ポスター発表 (Poster Sessions)

社会行動 Social Behavior
P3-2-123 対面視線あわせに同期した前頭・頭頂におけるガンマ帯域律動 Direct eye contact increases gamma-band oscillations in parietal and frontal cortices ○岩木直¹ ○Sunao Iwaki¹ 産業技術総合研究所ヒューマンライフテクノロジー研究部門¹ Human Technology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST)¹ Perception of facial expression and eye gaze direction of others is a key ability in typical social interaction. Recent neuroimaging studies have elucidated that the changes in eye gaze directed to the observer evoke specific neural responses in the middle frontal, the inferior temporal, superior parietal and the posterior superior-temporal regions. However, it is still unclear how the changes in the eye gaze direction between the directly facing subjects changes the spontaneous brain activities in the both subjects.Here we used neuromagnetic (MEG) and EEG recordings on both subjects, i.e., the sender and the observer of the eye gaze, to measure changes in the spontaneous brain activities while the observer perceives changes in eye gaze direction of the senderEEG and EOG signals from the sender and whole-head MEG signals from the observer were recorded simultaneously while the sender changed eye gaze direction, namely, (a) contact with (CONTACT) or (b) avert from the observer (AVERT). MEG and EEG signals were analyzed in the time-frequency domain to evaluate event-related changes in the spontaneous brain activities induced by the onset of eye movements.Significant increase in the gamma-band power was observed in the CONTACT condition compared to the averting condition at the MEG sensors covering the right superior parietal, bilateral posterior superior-temporal, and the frontal areas of the observer. Frequency-domain Granger-Geweke causality was used to test if there were causal connectivity between the areas where significant changes in gamma-band power were observed. The preliminary results indicate that the connectivity between (a) the bilateral frontal areas, and (b) the right frontal and parietal areas might be crucial for the perception of eye gaze of the directly facing person. The increase in gamma-band activities in these regions might reflect the integration of information processed individually in these regions for eye gaze perception.	P3-2-124 マウスにおけるアロ養育行動とオキシトシン神経系のテストステロンによる抑制 Testosterone inhibits alloparental responsiveness and oxytocin neural system in mice ○岡部祥太^1,2, 永澤美保¹, 茂木一孝¹, 菊水健史¹ ○Shota Okabe^1,2, Miho Nagasawa¹, Kazutaka Mogi¹, Takefumi Kikusui¹ 麻布大学大学院・獣医・動物・伴侶動物学研究室¹, 日本学術振興会特別研究員DC1² Companion Animal Research, Sch of Veterinary Medicine, Azabu Univ, Sagamihara¹, JSPS Research Fellow (DC1)² Parental behavior is enhanced by sensory stimuli from infants, and by changes in hormone levels. However, alloparental responsiveness in nonreproductive adults and involvement of hormones on it are not known well in mice. We firstly examined the effects of gonadal hormones on alloparental responsiveness in virgin mice. In retrieving test, the initial retrieving latency was shorter in females than males, and another sex difference was observed regarding pup sensitization; 5 times-pup exposures shortened the retrieving latency in females, but not in males. Gonadectomy neither influenced initial retrieving latency nor the pup sensitization in females. In contrast, gonadectomy shorterned the initial retrieving latency, and induced the pup sensitization in males. As compared with only gonadectomy, estrogen implant with gonadectomy further shortened the initial retrieving latency in males, but pup sensitization was not affected in both sexes. Testosterone implant impaired the pup sensitization in both sexes. We further examined the effect of gonadal hormones on oxytocin (OT) neural system. The number of OT immunoreactive (OT-ir) neurons in hypothalamic paraventricular nucleus was higher in females than males. In parallel with pup sensitization, gonadectomy affected only in males; the number of OT-ir neurons was increased by gonadectomy in males. As compared with gonadectomy, estrogen implant with gonadectomy did not affect the number of OT-ir neurons in both sexes. However, testosterone implant decreased the number of OT-ir neurons in both sexes. Considering the similar inhibitory effects of testosterone both to the pup sensitization and the number of OT-ir neurons, it was postulated that the sex difference of alloparental responsiveness was caused by inhibitory effect of testosterone via OT neural system in mice.
P3-2-125 メダカの群泳行動の誘発に動きのどのような側面が関与するのか？―バイオロジカルモーション刺激を用いた研究 What aspects of motion are involved in the induction of shoaling behavior in medaka?: studies using biological motion stimuli ○中易知大¹, 渡辺英治¹ ○Tomohiro Nakayasu¹, Eiji Watanabe¹ 基礎生物学研究所・神経生理学研究室¹ Laboratory of Neurophysiology, National Institute for Basic Biology¹ Many fish species are known to associate preferentially with conspecifics. Visual cues have been shown to play a crucial role in inducing shoaling behavior. For example, shoal size, sex, body coloration, and body size affects the formation of shoals. Using biological motion stimuli (depicting a moving creature by means of just a few isolated points), our previous study demonstrated for the first time that physical motion information is also involved in the induction of shoaling behavior. The present study examined what aspects of motion are important for the induction of shoaling behavior in medaka. We focused our attention on the temporal order (Experiment 1) and movement speed (Experiment 2). Biological motion stimuli were constructed based on the tracking data of medaka: six points were placed along the body trunk using computer software (Wriggle Tracker; Library, Tokyo, Japan). In Experiment 1, we compared the forward and reverse playback movies. In Experiment 2, there were five swimming speeds: the normal speed, two faster-than-normal speeds, and two slower-than-normal speeds. Shoaling behavior was assessed on the basis of the time for which the medaka were close to the display on which visual stimuli were presented and their travel distance in the test tank. It was shown that, whereas reverse playback of biological motion hardly interfered with the induction of shoaling behavior (Experiment 1), shoaling behavior was decreased in faster- and slower-than normal speed groups compared with normal speed group (Experiment 2). These results suggest that movement speed (but not temporal order) plays a critical role in the induction of shoaling behavior.	P3-2-126 男女による第2:4指比と海馬の安静時機能的結合の差異：fMRIを用いた検討 Sexual dimorphism of the relationship between hippocampal functional connectivity and second to fourth digit ratio: A resting-state fMRI study ○堂西倫弘¹, 寺田正樹², 金桶吉起¹ ○Tomohiro Donishi¹, Masaki Terada², Yoshiki Kaneoke¹ 和歌山県立医大・医・第1生理¹, 和歌山南放射線科クリニック² Dept of System Neurophysiol, Wakayama Med Univ, Wakayama, Japan¹, Wakayama-Minami Radiology Clinic, Wakayama, Japan² Hippocampus is known to be related to various cognitive functions and emotional control, as well as memory. Recent studies show that the hippocampal volume is affected by the prenatal androgen exposure as measured by the second to fourth digit ratio (2D:4D) in female. Thus, the hippocampus may be an important region to construct gender-related identity. We measured global functional connectivity in the hippocampus with other regions ("regional global connectivity," rGC), and examined its correlation with 2D:4D. A 3 Tesla MRI (Philips) with a 32-channel head coil was used to obtain structural (T1-weighted) and resting state functional (BOLD) images of healthy subjects (89 males and 84 females, 18-30 years old). During the acquisition (a series of three 5-min sessions), the subjects were asked to stay awake with their eyes closed. Preprocessing of BOLD signal was performed through SPM8 and MATLAB: head motion realignment, normalization with the standard EPI template, spatial/temporal smoothing and noise reduction. For each voxel (6x6x6 mm) in the gray matter, cross-correlation coefficients with all of other voxels were calculated and averaged to determine each vowels' rGC. The mean rGC value in the hippocampus was significantly higher for female subjects than that for male subjects (t-test, p<0.01). Pearson's correlation between rGC and 2D:4D revealed to be significant (p<0.01, corrected for multi-comparison with Monte Carlo simulation assuming a specified size of voxel cluster) at unilateral hippocampus, with negative correlation in males (on the right) and positive in females (on the left). The results suggest that, in female, the low global functional connectivity of the hippocampus is related to dominance and aggression that are known to be related to low 2D:4D. In contrast, high global functional connectivity in male may be related to the risk-taking decision making, since 2D:4D is known to be inversely related to the male day traders' ability.
P3-2-127 社会行動における脳内アロマテースの機能的役割：コモンマーモセットを用いたPET研究 Functional role of brain aromatase in social behavior: PET study with [¹¹C]cetrozole and [¹⁸F]FDG in common marmosets ○横山ちひろ¹, 川崎章弘¹, 林拓也¹, 高橋佳代¹, 細谷孝充², 渡辺恭良¹, 尾上浩隆¹ ○Chihiro Yokoyama¹, Akihiro Kawasaki¹, Takuya Hayashi¹, Kayo Takahashi¹, Takamitsu Hosoya², Yasuyoshi Watanabe¹, Hirotaka Onoe¹ 理研・分子イメージング¹, 東京医歯大・生体材料工学² RIKEN CMIS, Kobe¹, Dept Chem Biosci, IBB, Tokyo Med Dent Univ, Tokyo² Aromatase, an enzyme that converts androgens to estrogens, is located not only in the female reproductive organs but also in the brain of both genders, the latter thought to be involved in emotion and cognition. In this study, we performed positron emission tomography (PET) imaging of brain aromatase in the common marmoset (Callithrix jacchus) and analyzed its association with individual personality of social behaviors.The study was conducted using 12 adult male marmosets. Each animal was directly encountered by an unfamiliar marmoset for a period of 10 minutes, during which their social behaviors such as aggression, anxiety and friendliness were scored by factor analysis using individual behavioral measures. Regional aromatase distribution was measured by PET with [¹¹C]cetrozole, a novel PET probe for aromatase, and regional neural activity under a social condition, staying with an unfamiliar marmoset, was measured with a glucose analogue, [¹⁸F]FDG. While [¹¹C]cetrozole was specifically localized both in the amygdala and hypothalamus, aggression score was significantly correlated only with binding potential (BP) of [¹¹C]cetrozole in the hypothalamus. In addition, individual variation of the BP value in the hypothalamus was correlated with [¹⁸F]FDG uptake in the two medial parts of cerebral cortex, a positive correlation was found in the posterior cingulate cortex while a negative in the anterior cingulate cortex. The present results suggest that hypothalamic aromatase is involved in processing social behaviors by interacting with the medial cortical structures that is known to process self-social information.	P3-2-128 化学物質への生後幼弱期暴露が成長後の情緒社会性異常を引き起こすリスク評価に資するマーカー遺伝子群の探索 Search for genetic markers for the risk of the postnatal exposure to chemical compounds in emotion and social behavior after maturation ○片山敦子¹, 門間彰彦², 秋友孝文², 廣末愛², 星裕姫乃², 守口徹², 関野祐子¹, 佐藤薫¹ ○Atsuko Katayama¹, Akihiko Monma², Takafumi Akitomo², Megumi Hirosue², Yukino Hoshi², Toru Moriguchi², Yuko Sekino¹, Kaoru Sato¹ 国立医薬品食品衛生研究所薬理部¹, 麻布大学生命環境科学部² Lab Neuropharmacol, Div Pharmacol, NIHS, Tokyo¹, Dep Food Life Sci, Azabu Univ, Sagamihara-shi² It is anticipated that postnatal exposure to chemical compounds might affect the emotion and social behavior later in life. However, the assay system to clarify such risk has not been established. In this study, we attempted to search for genetic markers for the quantification of the risk of postnatal exposure to chemical compounds in emotion and social behavior after maturation. We used two well-known rat models of which emotion and social behavior after maturation became abnormal owing to the postnatal treatments, i.e., the administration of valproic acid (VPA) on postnatal day 14 (P14) and maternal separation (MS). We performed microarray analyses (Affymetrix, Rat 230.2 Array) of amygdalae from juvenile rats (P33-37) which had exposed to VPA (0.4-400 mg/kg) on P14 (P14SC) or separated from their mothers during lactation period. Because the rats which had been exposed to 400 mg/kg of VPA showed enhancement of anxiety in our study, we made a list of genes which had changed the expression levels in the same direction (even if increase or decrease) in all rats in 400 mg/kg VPA group. By principal component analysis (PCA) using these genes, VPA-exposed groups were discriminated from the control group in a dose dependent manner, though each fold change of expression level to control is not significant. Further, MS group was also discriminated from the control group by PCA, though the extent of the discrimination is less than that of 400 mg/kg VPA group. The listed genes could be the candidates for the genetic markers for the risk of postnatal exposure to chemical compounds in emotion and social behavior after maturation. Currently we are investigating the correlation of the PCA analysis data with the results of behavioral tests.
P3-2-129 外側中隔に発現するオキシトシン受容体の母性行動調節に関する機能 The potential role of oxytocin receptor expressed in the lateral septal nucleus in the regulation of maternal behavior ○佐藤佳亮¹, 日出間志寿¹, 浅山瑛美¹, 長田大知¹, 水上浩明², 西森克彦¹ ○Keisuke Sato¹, Shizu Hidema¹, Emi Asayama¹, Daichi Osada¹, Hiroaki Mizukami², Katsuhiko Nishimori¹ 東北大学大学院　農学研究科　分子生物学¹, 自治医大分子病態治療研究セ遺伝子治療研究部² Lab Mol Biol, Grad Sch Agric Sci, Tohoku Univ, Sendai¹, Div Genetic Therapeutics, Cent Mol Med, Jichi Med Univ, Shimotsuke² We have been studying the mice deficient in oxytocin or oxytocin receptor (Oxtr) genes, and suggested that this system had essential functions in the overall regulation of social behaviors. Maternal behavior was an important social behavior of female mice, and we reported impaired maternal behavior in Oxtr gene deficient (Oxtr -/-) mice (Takayanagi et al., 2005). OXTR-Venus knockin mice, generated in order to identify OXTR-expressing neurons, showed several nuclei with higher expression of OXTR, including the lateral septal nucleus (LS) and medial preoptic area (MPOA), the regions associated with maternal behavior (Yoshida et al., 2009). The number of c-Fos positive neurons with co-expression of OXTR was increased in the MPOA and LS of Oxtr-Venus knockin mice, during the parturition or when they did maternal behavior. We observed less increase in the numbers of c-Fos positive cells at the LS than the MPOA of Oxtr -/- female mice when exposed to pups compared with Oxtr +/+ female. We next injected AAV-Oxtr vector to the LS of Oxtr -/- female mice and observed rescued maternal behavior after parturition. Further experiment with infection of AAV-Cre vector to the LS nucleus of floxed-Oxtr mice did not show significant decrease in maternal behavior. These data not only suggested the critical role of OXTR expressed in the LS, and resultantly activated neural circuit in the same nucleus, but also implied an essential function of OXTR in the other nuclei than the LS for maternal behavior.In addition, we generated lox71 and loxJTZ17-based new AAV vector, as a new system to facilitate neuron type-specific gene expression. Any gene carried in this AAV vector, flanked by the mutant LoxP elements in an opposite direction, could be activated by inversion caused by Cre recombinase in one-directional way. Using this system, we could achieve neuron type-specific expression of the fluorescence protein gene.	P3-2-130 顔認知に網膜視蓋路が果たす役割 Facilitation of face recognition through the retino-tectal pathway ○中野珠実^1,2, 東田典子¹, 北澤茂^1,2 ○Tamami Nakano^1,2, Noriko Higashida¹, Shigeru Kitazawa^1,2 大阪大学大学院生命機能研究科¹, 大阪大学大学院医学系研究科² Graduate School of Frontier Biosciences, Osaka University, Osaka¹, Graduate school of medicine, Osaka University, Osaka² Humans can shift their gazes faster to human faces than to non-face targets, when they are required to choose between the face and non-face targets. However, it remains unclear whether the direct projection from the retina to the superior colliculus is involved in this facilitated recognition of faces in particular. To address this question, we presented a pair of face and non-face pictures to participants modulated in a gray scale in one condition, and modulated in a blue-yellow scale (S-cone isolating stimuli) in another. The information of the S-cone isolating stimuli is conveyed through the retino-geniculate pathway, but not through the retino-tectal pathway. With the gray-scale stimuli, the reaction time was shorter towards a face than towards a non-face target. The facilitatory effect in choosing a face disappeared with the S-cone isolating stimuli. Moreover, fearful faces elicited a significantly larger facilitatory effect as compared to neutral faces, when we presented face (with or without emotion) and non-face stimuli in a gray scale. The effect of facial emotion disappeared with the S-cone isolating stimuli. These results indicate that the facial and emotional information conveyed through the retinotectal pathway is responsible for the faster recognition of human faces.
P3-2-131 扁桃体内側核におけるエストロゲン受容体αまたはβの部位特異的ノックダウンにより雄マウスの社会的嗜好性は異なった影響を受ける Site-specific knockdown of estrogen receptor α or β in the medial amygdala differently affects social preference in male mice ○仲田真理子^1,2, 佐野一広¹小川園子¹ ○Mariko Nakata^1,2, Kazuhiro Sano¹, Sergei Musatov³, Sonoko Ogawa¹ 筑波大・行動神経内分泌¹, 日本学術振興会・DC2², コーネル大・医³ Behav Neuroendo, Univ Tsukuba, Japan¹, JSPS DC2², Weill Cornell Univ Med Col, USA³ Testosterone (T) is known to play a role in the regulation of male social behavior partly by acting on estrogen receptors (ERs) after being aromatized to estradiol. One of the target brain sites of T is the medial amygdala (MeA), which is involved in processing of social odors. It is still not known about the relative importance of ERα and ERβ, which are both localized in the MeA, for the regulation of social behavior in male mice. Here, we examined the effects of site-specific knockdown of ERα or ERβ in the MeA on social investigatory behavior in social preference tests with three different stimuli sets. Adult male ICR/Jcl mice were bilaterally injected with an adeno-associated viral vector that silences ERα (ERαKD) or ERβ (ERβKD), or a control vector into the MeA. They were tested for preference between a receptive female and a gonadally intact (intact) male (PTMF), between a receptive female and a gonadectomized (GDX) female (PTFF), and between a GDX male and an intact male (PTMM). In pre-injection PTMF and PTFF sessions, all mice investigated receptive females more than intact male or GDX female mice. In post-injection sessions, control animals sniffed receptive females longer in both PTMF and PTFF, and sniffed GDX males longer in PTMM. However, in ERαKD mice, sniffing time toward a GDX male was not different from that toward an intact male in the PTMM test although preference to receptive females in the PTMF and PTFF test was not affected. On the other hand, in ERβKD mice, sniffing time toward a receptive female was not different from that toward a GDX female in the PTFF test although they showed preference in the PTMF and PTMM test in a similar manner as the control group. These results suggest that ERα and ERβ in the MeA may be involved in different aspects of social preference regulated by gonad steroids in male mice.	P3-2-132 集団飼育下においてマウス社会性行動の解析を可能とする新システムの開発 Development of a novel analyzing system for social behavior of mice under group-housed conditions ○遠藤のぞみ¹, 宇治田和佳¹, 遠山千春¹, 掛山正心¹ ○Nozomi Endo¹, Waka Ujita¹, Chiharu Tohyama¹, Masaki Kakeyama¹ 東京大院・医・健康環境医工学部門¹ Lab. Env. Health Sci., Grad. Sch. of Med., Univ. of Tokyo., Tokyo¹ Behavioral analysis of laboratory rodents is extremely important because it may be able to provide a clue to unveil the mechanisms underlying a variety of brain functions. Among brain functions, the necessity to understand social behaviors has been increasing because understanding of the mechanisms of social behaviors in rodent models can be used to elucidate the mechanisms of social behavior disorders observed in human mental illnesses. Although the signs and symptoms of social behavior disorders manifest in the social context, behavioral tests that have been used to analyze sociality are to assess a relationship between only two animals. For example, these tests include aggressive behavior test, sexual behavior test, and three chambers test, that are used under simplified unnaturally-formed conditions for a short period. To study social behaviors of animals under more naturally-formed social context over a long period, it should be prerequisite to develop a behavior analyzing system that can automatically identify an individual animal any time and assess behaviors under group-housed conditions. We here introduce our newly developed behavior-analyzing system using video image analyzing for individual mice identification under group-housed conditions. In this system, mice that were labeled with a unique symbol were taken by an infrared camera, and identified by an originally developed software based on the pattern recognition technique. The location of each mouse was recorded as an X-Y coordinate over several weeks. This novel technique was used to tackle behavior assessments under group-housed conditions, and could be an asset for experiments using rodent models in a variety of biomedical studies.
P3-2-133 母子分離が成熟後におけるマウスの競争行動に及ぼす影響 Characterization of the Lasting Impact of Maternal Separation on Competitive Behavior in Mice ○べナー聖子¹, 遠藤のぞみ¹, 遠藤俊裕¹, 西村典子¹, 吉岡亘¹, 倉繁秋江¹, 遠山千春¹, 掛山正心¹ ○Seico Benner¹, Nozomi Endo¹, Toshihiro Endo¹, Noriko Nishimura¹, Wataru Yoshioka¹, Akie Kurasige¹, Chiharu Tohyama¹, Masaki Kakeyama¹ 東京大院・医・疾生セ・健康環境医工学部門¹ Lab. Environ. Health Sci., CDBIM, Grad. School of Med., The University of Tokyo, Tokyo, Japan¹ The significance of the early life stress (ELS) in the programming of social behavior is evident from numerous epidemiological and animal studies. Nevertheless, experimental resources are limited in evaluating the lasting impacts of ELS under a socially stressful context which is a risk factor for psychopathogenesis in humans. The present study thus aimed to characterize the ELS-induced behavioral phenotypes in mice under social stress, and accordingly define the mPFC-amygdala activities in which its relational imbalance is associated with various forms of psychopathology. We adopted maternal separation (MS) as an ELS model, and the group-housed competition task in IntelliCage (Endo et al., PONE, 2012) as a social stress. MS mice were generated by separating the pups from their dams for 180 min per day during postnatal days (PND) 1-4. Post PND 80, the IntelliCage-based competition task was conducted (n8/group) where water drinking was permitted 3 hr a day, subjecting mice to compete for water. Mice quicker to reach the peak of the water access were considered "dominant" compared to the mice with a delayed peak. Immediate early gene (IEG) expressions in the mPFC and the amygdala were quantified by the Laser microdissection-RTqPCR, as a neural activity index. The behavioral analysis revealed that the MS mice exhibited dominance over the controls, as their access peak rose earlier than that of the controls'. Isolating the groups shifted the control's peak to superimpose that of the MS mice, which again was pushed back as the groups were share-housed. The IEG expressions between the mPFC-amygdala during the competition showed positive correlation in the MS group, while it correlated negatively in the controls. The results suggest that the neonatal MS treatment produces dominancy under competitive social stress in mice, and the exacerbated amygdala activity in relation to the mPFC presumably underlies the manifested phenotype.	P3-2-134 強制音声曝露による雄マウス超音波発生の変化 Artificial auditory environment can modulate male mice vocal characters ○菅野康太^1,2, 浅場明莉¹, 横山和樹¹, 永澤美保¹, 茂木一孝¹, 菊水健史¹ ○Kouta Kanno^1,2, Akari Asaba¹, Kazuki Yokoyama¹, Miho Nagasawa¹, Kazutaka Mogi¹, Takefumi Kikusui¹ 麻布大学・獣医・動物・伴侶動物学研究室¹, 日本学術振興会特別研究員PD² Companion Animal Research, Sch of Veterinary Medicine, Azabu Univ, Sagamihara¹, JSPS Research Fellow (PD)² Male mice emit ultrasounds when encountering females or their urine. The ultrasound vocalization contains song-like structure and recent studies have focused in the detail analysis of the characteristic of the songs, such as syllable compositions or temporal sequence of syllables. We have demonstrated that male mice have a strain specific profiles of the songs (Kikusui et al. 2011, Sugimoto et al. 2011), and this character was not changed by cross-fostering, in which auditory environment during the neonatal period were supposed to be manipulated. In the present study, we tried again to examine the possibility of vocal learning, by using a novel method to change early auditory environments. We raised the male C57BL/6 (B6) pups under the condition of the artificial exposure of BALB/c (BALB) songs emitted from ultrasounds-speaker. As a result, the mice exhibited altered vocalization; patterns of syllable types in songs became simple compared to normally raised B6 and BALB mice. However, this indicated that there was no evidence of positive vocal learning. We also examined two indexes in this experimental model: one was sexual behavior, which was reported to be related to the occurrence of a specific syllable types. The other was c-fos immunoreactive cells as a neuronal activity marker in response to female urine. Because it had reported that neuronal lesion of the amygdala resulted in emitting simple patterns of syllables, the c-fos immunoreactivity in the amygdale was analyzed. The results demonstrated that the mice artificially exposed to songs in the neonatal period showed normal sexual behavior as well as the c-fos immunoreactivity in the amygdala even they emitted different pattern of syllables. Taken our previous study together, these data supports the hypothesis that mice songs are mostly regulated by genes and little contribution of vocal learning, but there is certain plasticity in the syllable compositions dependent on the rearing environments.
P3-2-135 社会的随伴性認知の神経基盤 Neural substrates of social contingency ○佐々木章宏¹, 北田亮^1,2, 岡本悠子^1,2, 定藤規弘^1,2 ○Akihiro T Sasaki¹, Ryo Kitada^1,2, Yuko Okamoto^1,2, Norohiro Sadato^1,2 生理学研究所心理生理¹, 総合研究大学院大学生理科学専攻² Div. Cerebral Integration, Natl. Inst. for Physiol. Sci., Okazaki, Japan¹, Grad. Univ. for Advanced Studies, Okazaki, Japan² For the social interaction, such as reciprocal imitation, it is important to perceive that one's own and other's actions are contingent, which seems to be detected by comparison of those. It has been reported infants initially prefer to perfect contingency, such as one's own action and its consequence, leading to agency perception. Subsequently, infants change their preference to high-but-imperfect contingency, such as being imitated by others, leading to social contingency perception. This suggests contingency detection system extends its function to perceive social contingency as well as agency, allowing us to assume common neural substrates may be involved. Although previous studies suggested the extrastriate body area (EBA) was involved in detection of agency and self-other congruency, unknown is whether neural substrates of agency and social contingency are shared.26 healthy right-handed subjects participated in the study. They performed visuo-motor matching task, where they moved their finger according to auditory instruction, and judged the level of contingency between subjects' own and visually presented finger movements. Visual stimuli were varied in the feedback type (self-action or other's-action), congruency between performed and presented actions (congruent or incongruent), and presentation timing (with or without delay).Region-of-interest analysis, within functionally defined EBA, revealed bilateral EBA significantly activated when viewing of congruent actions compared with incongruent actions (congruency effect), irrespective of feedback type and timing. Whole brain analysis revealed left inferior frontal gyrus (IFG) showed significant congruency effect when self-actions were presented WITHOUT delay, conversely, same effect was observed when other-action was presented WITH delay.Thus, we suggest that EBA is involved simple coding for form of finger posture, while the left IFG is involved in complex coding for social relevance.	P3-2-136 コモン・マーモセットの社会性発達におけるバルプロ酸の影響 Prenatal exposure to valproic acid (VPA) alters social interactions in common marmoset infants: An autistic-like primate model ○安江みゆき^1,3, 中神明子^2,3, 中垣慶子³, 一戸紀孝³, 川合伸幸^2,3 ○Miyuki Yasue^1,3, Akiko Nakagami^2,3, Keiko Nakagaki³, Noritaka Ichinohe³, Nobuyuki Kawai^2,3 日本女子大学大学院人間社会研究科¹, 名古屋大学大学院情報科学研究科², 国立精神・神経医療研究センター神経研究所³ Graduate School of Integrated Arts and Social Sciences, Japan Women's University, Kawasaki¹, Graduate School of Information Science, Nagoya University, Nagoya², Research National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo³ Although various types of rodent models for autism including valproic acid (VPA) syndrome have been produced, these non-primate animals, as being rodents, do not always reproduce human complex social behaviors. In contrast, primates demonstrate complex social interactions as humans do.The present study is one of our on-going project to establish a primate model for autism. Model primates (common marmosets) were exposed to VPA during gestation period. To establish these primates as an animal model for autism, behavioral assays with high relevance to diagnostic criteria of autism spectrum disorders (ASD) are required. We assessed social interaction of marmosets in a behavioral test commonly used for mouse models, a three-chambered approach task, which scores time spent in a side chamber with a novel conspecific animal versus time spent in the other side chamber with a non-social novel object.Results show that the VPA marmoset infants spent more time in a side chamber with an unfamiliar marmoset over the other side with an empty cup, as the age-matched control primates did. We also scored the time looking at an unfamiliar marmoset. Despite staying in the same chamber with an unfamiliar conspecific, the VPA marmosets less attended to the unfamiliar marmoset than the control marmosets. The amount of attention to an unfamiliar marmoset was also different between two groups even in the center chamber: the control marmosets looked longer at an unfamiliar marmoset than the VPA marmosets. Although the VPA marmosets preferred to stay in a side chamber with an unfamiliar animal, they paid less attention to the conspecific. These behaviors seem to be parallel to those of autistic people, that was not reproduced by any of the rodent models. These results suggest that the VPA marmosets show social interaction deficit in the early developmental period and thus can be a promising primate model for ASD.
P3-2-137 胎生期PCB曝露が乳児期バイオロジカルモーション知覚発達に及ぼす影響 Influences of prenatal exposure to polychlorinated biphenyl (PCB) congeners on biological motion perception during early infancy ○土居裕和¹, 西谷正太¹, 永井知子¹, 藤澤隆史¹, 掛山正心², 前田隆浩¹, 篠原一之¹ ○Hirokazu Doi¹, Shota Nishitani¹, Tomoko Nagai¹, Takashi Fujisawa¹, Masaki Kakeyama², Takahiro Maeda¹, Kazuyuki Shinohara¹ 長崎大学大学院医歯薬学総合研究科・神経機能学分野¹, 長崎大学大学院医歯薬学総合研究科², 東京大学大学院医学系研究科³ Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan¹, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki City, JAPAN², Graduate School and Faculty of Medicine, The University of Tokyo, Tokyo, JAPAN³ The recent surge of ASD and the ASD-like behavioral problems at subclinical level in young population is said to be partly attributable to the neurotoxicity of chemical-environments. To examine this possibility, we investigated the link between the ASD-like deficiencies in social cognition during infancy and the prenatal exposure to PCB congeners by a prospective birth-cohort design. As an indicator of socio-cognitive ability, preference towards upright- over inverted-biological motion stimuli was measured in 40 four-month-olds, and the link between preferential looking pattern and levels of prenatal exposure to PCB congeners was examined by step-wise multiple regression analysis. The results revealed a positive correlation between the concentration of dioxin-like PCB #118 and the fixation duration on inverted-biological motion. Likewise, infants with high level of PCB#118 exposure failed to show normal preference towards upright biological motion stimuli in contrast to infants with low exposure level. These results indicate a potential link between postnatal manifestation of ASD-like social deficits and the prenatal exposure to PCB congeners.	P3-2-138 コモンマーモセットの音声発達におけるバルプロ酸の影響 The marmoset infants exposed to valproate acid during gestation period vocalize a limited call with fixed intervals: A primate model for autistic syndrome disorder ○中神明子^1,2, 坂野拓¹, 安江みゆき^1,3, 中垣慶子¹, 一戸紀孝¹, 川合伸幸^1,2 ○Akiko Nakagami^1,2, Taku Banno¹, Miyuki Yasue^1,3, Keiko Nakagaki¹, Noritaka Ichinohe¹, Nobuyuki Kawai^1,2 （独）国立精神神経医療研究センター　神経研究所¹, 名古屋大院　情報科学², 日本女子大学³ National Center of Neurology and Psychiatry¹, Graduate school of Information Science, Nagoya Univ², Japan Women's Univ³ It is important to produce an animal model for studying autism spectrum disorder (ASD) to examine the underlying neural mechanisms. Although some animal models have been proposed in rodents, only a few models demonstrate all of the three core features: impaired social interaction, communication and restricted and repetitive behavior. Among others, impaired communication skill (vocalization) has been the most difficult feature to implicate in rodent models because of their poor vocal repertoire.Currently, we are in process of making a primate model for ASD. The present study is one of our on-going projects to establish a primate model for autism. Model primates (common marmosets) were exposed to valproate acid (VPA) during gestation period. To establish these primates as an animal model for autism, behavioral assays with high relevance to each category of behavioral criteria are required.We recorded infant marmosets' vocalization once in a week after birth and analyzed their sequential calls recorded in 5-minute sessions. We found significant difference in their vocalization patterns between control and VPA marmosets 3 weeks after birth. The variety of call types used by VPA marmosets was very limited compared to their age-matched controls. The distribution of inter-call interval histogram was also different between control and VPA marmosets; The inter-call interval histograms of control marmosets had a long heavy tail but such a tail could not be observed in those of controls. These results indicate VPA marmosets used a limited number of call types with a relatively fixed utterance interval, and suggest that the VPA marmoset have a deficit in communication and repetitive tendencies, which are core features of autism.
P3-2-139 mGluR7を介した攻撃行動発現調節のメカニズムの解明 Regulation of aggressive behavior by mGluR7 ○馬杉（時田）美和子¹, , 河田光博¹ ○Miwako Masugi-Tokita¹, Peter Josef Flor², Mitsuhiro Kawata¹ 京府医・生体構造科学¹ Dept of Anatomy and Neurobiology, Kyoto Prefectural Univ of Med, Kyoto¹, Lab of Molecular & Cellular Neurobiology, Univ of Regensburg, Regensburg, Germany² Metabotropic glutamate receptors (mGluRs) consist of eight different subtypes and exert their effects on second messengers and ion channels via G-proteins. The function of individual mGluR subtypes in the CNS, however, largely remains to be clarified. We examined the aggressive behavior in male wild-type and mGluR7 knockout littermates, using a resident-intruder paradigm. Wild-type mice displayed intense aggression against olfactory bulbectomized intruders. In comparison, mGluR7 knockout (KO) mice showed significantly reduced levels of aggression. We also found that mGluR7 KO mice seldom showed anogenital sniffing against intruders.Olfaction is known to be the essential component for the recognition of male pheromones that elicit aggressive behaviors. Although mGluR7 is widely distributed in the brain, intense expression is found both in main and accessory olfactory system. To investigate the mechanism of altered aggression, we further assessed urine preference of mGluR7 KO mice. Two cotton pads wetted with different odorant sources were presented simultaneously to the mice. Wild-type mice spent longer time to sniff male urine than saline, but mGluR7 KO mice did not show such preference.To examine olfactory processing, we analyzed c-Fos-immunoreactive (IR) cells in several nodes of the accessory olfactory pathway after exposure to urine. We found a reduction in Fos-IR cells in the bed nucleus of the stria terminalis (BNST) of mGluR7 KO mice, while no significant difference was observed in those of accessory olfactory bulb. To further examine the site of action, we injected the selective mGluR7 antagonist MMPIP into several brain regions including the BNST, and observed behavioral changes. These results indicate that altered olfactory processing could be the cause of reduced aggression of mGluR7 KO mice.	P3-2-140 母親からの働きかけにより誘発される父親両親行動としての仔運び行動とFos発現 Mouse pup retrieval as paternal parental behavior and Fos expression following communicative interaction with maternal mates ○鍾静¹, 梁明坤¹, 馬文ショウ¹東田陽博¹ ○Jing Zhong¹, Mingkun Liang¹, Wenjie Ma¹, Shirin Akther¹, Haruhiro Higashida¹ 金沢大学子どものこころの発達研究センター¹ Research Center for Child Mental Development, Kanazawa University Graduate School of Medicine, Kanazawa, Japan¹ Although a number of animal models have been used in experimental studies of paternal care, in view of its value for genetic studies, a mouse of paternal care could be especially useful. While some strains of the laboratory mouse Mus musculus become biparental, there is little information about what specifically induces male parental behavior.In the present study, we have addressed the above question regarding factors that determine male parental care using laboratory mice of the outbred ICR strain (originally obtained from the Charles River Laboratories in 1965 and since then bred in Japan; alternative name, Swiss CD1). The ICR mice are uniparental but a good model for parental behavior, because they very actively reproduce, and exhibit easily-monitored pup-retrieval after separation, which is reliable indicator of parental behavior. We show that male ICR mice demonstrate robust parental care, which is induced by signaling from the mother, after separation from the pups. We show that this mediated through olfactory and auditory cues, and that the male response can be modified hormonally via oxytocin and through the central cholinergic system.Additional questionnaire is the neural circuit for paternal parental behavior. We compared neuronal activation in ICR male mice which show or do not show retrieval of pups by quantifying c-fos immunoreactivity in several brain area. The Fos positive cells are significantly detected in the brain region of medial preoptic area (MPOA) during paternal parental behavior. This result suggests, in the neuronal circuit, MPOA play an important role in paternal parental care.
P3-2-141 母親からの働きかけにより誘発される父親両親行動としての仔運び行動とオキシトシン Mouse pup retrieval as paternal parental behavior and oxytocin´s roles following communicative interaction with maternal mates ○梁明坤¹, 鍾静¹, 馬文ショウ¹東田陽博¹ ○Mingkun Liang¹, Jing Zhong¹, Wenjie Ma¹, Shirin Akther¹, Haruhiro Higashida¹ 金沢大学子どものこころの発達研究センター¹ Research Center for Child Mental Development, Kanazawa University Graduate School of Medicine¹ Accumulated evidence reveals that parental care is partly determined genetically in monogamous animals. However, a mouse non-biparent model of paternal care is useful, because some strains of the laboratory mouse Mus Muscles become biparental. And there is little information about what specifically induces male parental behavior.In the present study, we identified the laboratory mice of the outbred ICR strain (originally obtained from the Charles River laboratories in 1965 and since then bred In Japan; alternative name, Swiss CD1) is suitable for male parental researches. The ICR mice are uniparental but a good model for parental behavior, because they very actively reproduce, and exhibit easily-monitored pup-retrieval after separation, which is a reliable indicator of parental behavior. We show that male ICR mice demonstrate robust parental care, which is induced by signaling from the mother, after separation from the pups. We show that this signaling is mediated through olfactory and auditory cues. Here we report some evidence based on the hypothesis that the male responses can be modified hormonally via oxytocin and through the central cholinergic system. By using the brain microdialysis method, we collected cerebrospinal fluid for measuring oxytocin levels and applied oxytocin directly to the brain for monitoring mouse parental care.	P3-2-142 母から隔離された子デグーの発声中におけるFoxp2遺伝子の脳内発現 Foxp2 gene expression in pups brain of Octodon degus during the vocalization after they are separated from their mother ○別所親房¹, 武市直弥¹, 長手翔吾¹, 阿部将卓¹ ○Chikafusa Bessho¹, Naoya Takeichi¹, Shogo Nagate¹, Masataka Abe¹ 京都産業大学理学部物理科学科¹ Dept Physics, Kyoto Sangyo Univ, Kyoto¹ FOXP2 was the first gene linked to human speech and language and many animal models have been developed to study the function of FoxP2 in vocal learning. Mice pups vocalize in ultrasonic region when they are removed from their mothers. We used degu as an animal model. The degu (Octodon degus) is a small rodent and they are highly social. They have an elaborate vocal repertoire comprising up to 15 unique sounds. Degu pups vocalize at audible range when they are separated from their parents. A degu pup was taken out of the home cage and placed for thirty minutes in another litter. A digital voice recorder was placed over the pup. Three minutes of recording commenced after the pup vocalized. Sonographs were got by FFT Analyzer soft. A pup was anesthetized and sacrificed thirty minutes after recording and the whole brain was removed. A brain was cut in two sagittal section and the left brain section was fixed in 4 % paraformaldehyde in PBS(pH 7.4) over night at 5°C. Sections with 50μm were reacted with EGR-1 antibody or FOXP2 antibody over night at 5°C, then washed in PBS and were incubated in Alex488 conjugated goat secondary antibody for 1-2 hr at room temperature in dark , rinsed in PBS. Green fluorescence of slices in blue light (490 nm) was observed with the aid of an inverted fluorescence microscope . Images of fluorescence were recorded and pseued color images were made . We got three conclusions. 1. Call frequencies of 4-6 day old degu pups separated from parents are covered about 600-3500 Hz. 2. Mean fluorescent intensity of antibody EGR-1 in the hippocampus and striatum of separated pup is stronger than the intensity in those regions of control . 3. Mean fluorescent intensity of antibody FOXP2 in the hippocampus and striatum of separated pup is stronger than the intensity in those regions of control.We are trying to study the Foxp2 gene expression by in situ hybridization.
P3-2-143 過剰な攻撃行動を引きおこす神経メカニズム：背側縫線核5-HT神経のグルタミン酸による制御 Escalated aggression by the activation of 5-HT system via glutamate in the dorsal raphe nucleus ○高橋阿貴¹, 小出剛^1,2 ○Aki Takahashi¹, Tsuyoshi Koide^1,2 遺伝研・マウス開発¹, 総研大・生命科学・遺伝学² MGRL, National Institute of Genetics, Mishima¹, Dept Genetics, School of Life Science, SOKENDAI, Mishima² The serotonin (5-HT) system in the brain has been studied more than any other neurotransmitter for its role in the neurobiological basis of aggression. However, which mechanisms modulate the 5-HT system to promote escalated aggression is not clear. The 5-HT neurons in the mammalian forebrain originate mainly from the dorsal raphe nucleus (DRN). Previously, we showed that a pharmacological activation of GABA(B) receptors in the DRN increased 5-HT release in the medial prefrontal cortex, and also escalated aggressive behavior in male mice. The increase of 5-HT release in one of the projection areas of the DRN suggests that the indirect disinhibition of 5-HT neuron activity by presynaptic GABA(B) receptors on non-5-HT neurons in the DRN is involved in escalated aggression. To examine which neurons are the target of GABA(B) agonist baclofen to escalate aggression, we measured the release of glutamate and GABA in the DRN using in vivo microdialysis. We found that there was a phasic increase of glutamate, but not GABA, release in the DRN by the local administration of baclofen. To see whether the increase of glutamate input in the DRN can escalate territorial aggression in male mice, we then examined the effect of direct injection of L-glutamate into the DRN. Our data showed that the glutamate microinjection into the DRN enhanced aggressive behavior dose-dependently. Thus, glutamatergic input into the DRN seems to be the modulator of escalated aggression. To understand the role of glutamate input in the DRN further, we are currently examining the level of extracellular glutamate in the DRN during the exposure to a male opponent (social instigation). Social instigation procedure is known to enhance territorial aggression in rodents, and the role of glutamatergic modulation in the DRN for this instigation procedure will be discussed.	P3-2-144 人のふりみて我がふり直せるラット Rats can better themselves by observing others ○請園正敏^1,2, 高野裕治^2,3, 間山広江^1,2, 廣中直行⁴ ○Masatoshi Ukezono^1,2, Yuji Takano^2,3, Hiroe Mayama^1,2, Naoyuki Hironaka⁴ 明治学院大学¹, CREST, 科学技術振興機構², NTTコミュニケーション科学基礎研究所³, 三菱化学メディエンス⁴ Meijigakuin University, Tokyo¹, CREST, JST, Kanagawa², NTT Communication Science Laboratories, Kanagawa³, Mitsubishi Chemical Medience, Kumamoto⁴ Human beings have the inherent ability for observational learning. Over the history of observational learning in animals, some experimental psychologists have been skeptical about observational learning in laboratory animals, but ethologists have observed many cases of observational learning in wild animals. The problem here is the disagreement between the psychology and ethology camps. We have successfully replicated the proverb "One man's fault is another man's lesson" in laboratory rats. In a maze for laboratory rats, observer rats watched other animals' (demonstrator) foraging behavior and then foraged in turn. The demonstrators showed inefficient exploration, but the observers, having observed the demonstrator's inefficiency, explored in a more efficient manner. The efficient learning in the observers could not be explained by existing learning theory in psychology. Our study showed laboratory rats have observational-learning ability. Moreover, this observational learning is not just a copying behavior but recreated knowledge. In this aspect, the results are quite new and will have an impact in psychology and ethology. In the near future, it will also have positive spillover effect in medicine, pharmacology, and neuroscience. These disciplines will become intent on solving the problems associated with communication disorders. Thus, the experiment developed by this study would be useful for basic research on brain functions in communication.
P3-2-145 選択肢の数とその社会的平等は報酬系の異なるコンポーネントに表現される Increasing number of choice options and their social equality are represented by dissociable components of the human reward system ○青木隆太^1,2, 松元まどか¹, 蓬田幸人^1,2, 出馬圭世^2,3, 村山航^2,4, 杉浦綾香⁵松元健二¹ ○Ryuta Aoki^1,2, Madoka Matsumoto¹, Yukihito Yomogida^1,2, Keise Izuma^2,3, Kou Murayama^2,4, Ayaka Sugiura⁵, Colin F. Camerer³, Ralph Adolphs³, Kenji Matsumoto¹ 玉川大学脳科学研究所¹, 日本学術振興会², 東京大学大学院総合文化研究科広域科学専攻生命環境科学系認知行動科学大講座⁵ Brain Sci Inst, Tamagawa Univ, Tokyo¹, JSPS, Tokyo², Caltech, Pasadena, USA³, UCLA, Los Angeles, USA⁴, Dept Life Sci, GSAS, Univ of Tokyo, Tokyo⁵ A large literature in neuroscience has described brain regions within which BOLD-fMRI tracks the value of stimuli and outcomes, notably including the ventral striatum (VS) and ventromedial prefrontal cortex (vmPFC). Here we investigated a distinct aspect of choice: the value presented by the sheer number of options available, regardless of actual outcome. Furthermore, we investigate the relative coding of this type of value when the choices offered are one's own, or those of another person. A two-person game between 20 healthy participants (SELF) and a confederate (OTHER) presented numbers of options for each player that were manipulated independently (1, 2, or 4 options) on a trial-by-trial basis. Reward outcomes were at a fixed 50% probability regardless of the number of options. After the fMRI scan, participants were asked to rate their emotional response to the numbers of options. Analysis of the post-scan subjective ratings revealed that the more equal the number of options between players, the more positive the emotional valence. Neuroimaging results showed that the number of options for SELF, but not for OTHER, was significantly associated with increased VS activation. Furthermore, the relative responsiveness of the VS to the number of options for SELF (compared to that for OTHER) was positively correlated with the subjective ratings across individuals. The degree of equality was significantly associated with activation in the vmPFC, and its responsiveness was positively correlated with the subjective ratings. Notably, the same voxels from the VS and vmPFC were significantly activated by reward outcome for SELF and the equality of outcome amongst the two players. The findings suggest that similar mechanisms are recruited not only when we obtain rewarding outcomes, but also when we have a greater number of options to freely choose among; and not only on trials with greater equity of reward outcomes, but also in greater equity of options available for choice.	P3-2-146 攻撃行動選択交配系雄マウスにおける活動性の解析 Running-wheel activity and home-cage activity in male mice selectively bred for aggression ○永田知代¹, 津田夢芽子¹, 小川園子¹ ○Kazuyo Nagata¹, Mumeko C. Tsuda¹, Sonoko Ogawa¹ 筑波大学人間系行動神経内分泌学研究室¹ Laboratory of Behavioral Neuroendocrinology, University of Tsukuba, Tsukuba, Japan¹ In our recent studies, we examined the relationship between levels of aggression and anxiety- and emotionality-related behaviors. However, the link between aggression and locomotor activity are less understood. In the present study, we focused on measuring locomotor activity in running-wheel (RW) and home-cage (HC) tests in three lines of gonadally intact male mice selectively bred for their levels of aggression, i.e. low-aggression (LAL), high-aggression (HAL), and non-selective control (NSL). They were tested for either RW or HC activity for 14 days under a 12:12 light-dark cycle. Although three lines of mice did not differ in their RW activity levels (number of daily wheel revolutions) during the dark phase, there were clear line differences in activity during the light phase. LAL mice showed significantly lower levels of activity compared to NSL mice during the light phase. Moreover, within-day pattern of RW activity differed between lines. In HAL and NSL mice, RW activity started to gradually increase during the last 2-3 hr of the light phase and continuously increased in the dark phase. On the other hand, RW activity in LAL mice did not show any increase before lights off but rather increased abruptly during the first 2 hr of the dark phase. In contrast, there were no line differences in levels of HC activity during both light and dark phases. However, within-day pattern of HC activity clearly differed across the three lines. HC activity in HAL and NSL mice gradually increased during the last 3 hr of the light phase and reached maximum levels in the first 1 hr of the dark phase. In LAL mice, increase in HC activity was only seen right after lights off and then peaked about 2 hr into the dark phase. Moreover, only NSL, but not HAL and LAL, mice showed a secondary peak of HC activity during the last 3 hr of the dark phase. These results collectively suggest the possibility of alterations in regulatory mechanisms of light-associated activity levels in LAL mice.
P3-2-147 新規なデータマイニング法を用いたメダカ集団学習に関わる行動法則の同定 Identification of behavioral rules underlying social learning in medaka fish using a novel data mining method ○竹内秀明¹, 末廣勇司^1,2, 久保健雄¹, 落合崇¹ ○Hideaki Takeuchi¹, Yuji Suehiro^1,2, Takeo Kubo¹, Takashi Ochiai¹ 東京大学大学院理学系研究科生物科学専攻¹, 東京女子医大第二生理学教室² Dept Biol Sci, Grad Sch of Sci, Uni of Tokyo, Tokyo¹, Dept of Physiol, Tokyo Women's Med Univ Sch of Med, Tokyo² Social animals obtain adaptive information regarding food or predators rapidly and efficiently using 'social learning', which is defined as learning that is influenced by observing or interacting with other members. Few studies to date, however, have examined the behavioral cause-and-effect relationship among group members that mediates this social learning. To approach this subject, we constructed a behavioral paradigm where the 'social learning' is observed using medaka fish and established a novel data mining method to search for the behavioral cause-and-effect relationship. We first established a behavioral paradigm for visual food learning using medaka fish to show that a single fish can learn to associate a visual cue with a food reward. Grouped medaka fish (6 fish) learned to associate the visual cue with a food reward more rapidly than a single fish, indicating that social learning occurred in medaka fish. We then studied the behavioral properties that induce inter-individual interactions, such as coordinated movement, using a data-mining method based on Jensen Shannon Divergence (JSD). In addition, high-speed movement of a focal fish tended to transiently and locally induce the coordinated movement (alignment) of other members under free-swimming conditions without presenting the visual cue. High-speed movement of the informed and trained fish during the visual cue presentation facilitated the movement of naive fish in response to the same visual cues, suggesting the involvement of the social learning. Compared with the naive fish, the informed and trained fish tended to induce coordinated movement of other naive fish, suggesting the possible involvement of individual recognition in social learning. The data-mining method used in the present study can be a powerful method to search for factors associated with inter-individual interactions using a dataset for time-series coordinate data of individuals even in other animal social behaviors.	P3-2-148 ミラーニューロンシステムに関連した足運動模倣時の脳律動変化 Mirror neuron system during the imitation of foot movement in magnetoencephalography ○菅田陽怜¹, 平田雅之¹, 佐織友子², 後藤哲³, 柳澤琢史^1,2,4, 荒木俊彦², 吉峰俊樹¹, 依藤史郎² ○Hisato Sugata¹, Masayuki Hirata¹, Tomoko Saori², Tetsu Goto³, Takufumi Yanagisawa^1,2,4, Toshihiko Araki², Toshiki Yoshimine¹, Shiro Yorifuji² 大阪大学大学院医学系研究科脳神経外科¹, 大阪大学大学院医学系研究科神経機能診断学², 河内総合病院脳神経外科³, 国際電気通信基礎技術研究所脳情報研究所⁴ Department of Neurosurgery, Osaka University Medical School¹, Division of Functional Diagnostic Science, Osaka University Graduate School of Medicine, Osaka², Department of Neurosurgery, Kawachi General Hospital, Higashi-osaka city, Osaka³, ATR Computational Neuroscience Laboratories, Kyoto⁴ Objective: Mirror neuron system (MNS) is known to be related to understanding and imitation of action. We investigated neuromagnetic oscillatory changes during observation of action with intention to imitate in order to delineate the neural process underling the MNS. Methods: Fourteen healthy subjects participated in our study. After the pre-conditioning stimuli which indicate execution or observation, subjects observed two types of visual stimuli: an animated foot (dorsiflexion of ankle joint): and a static foot (a cross appeared on the foot). According to the pre-conditioning stimuli, the subjects dorsiflexed the ankle joint, or just looked at the finger. Beamforming analyses were used to delineate the oscillatory changes. Results: Oscillatory changes were observed in the following areas: bilateral superior parietal lobules (SPL), bilateral ventral premotor cortices (PMv), left superior temporal cortices, right fusiform gyrus. Left PMvs were desynchronized during execution of the foot or just during observation of the animated foot, whereas right PMv were desynchronized during just execution of the foot. Furthermore, desynchronizations in temporal and premotor cortices peaked faster than that in SPL. Conclusion: Our results suggest that these oscillatory changes reflect the activity of the MNS underling imitation of action. SPL may have key function to integrate information from different regions and form precise motor representation. Left and right PMvs may have different function as for imitation of movement; left PMv is involved in observation of movement and right PMv is associated with imitation or intention of movement. In addition, temporal cortices were activated during imitation of movements, suggesting that these areas also constitute the MNS.
P3-2-149 未経験雄における養育行動－単飼による効果－ Display of paternal mouse pup crouching behavior following social isolation of virgin males ○折笠千登世¹, 永岡謙太郎², 近藤保彦³, 佐久間康夫⁴ ○Chitose Orikasa¹, Kentaro Nagaoka², Yasuhiko Kondo³, Yasuo Sakuma⁴ 日医大・システム生理¹, 東京農工大院・農学・動物生命科学², 帝京科学大学・生命環境・アニマルサイエンス³, 東京医療学院大・保健医療⁴ Dept Physiol, Nippon Medical School, Tokyo¹, Tokyo Univ Agriculture and Technol, Tokyo, Japan², Teikyo Science Univ, Tokyo, Japan³, Univ Tokyo Health Sci, Tokyo, Japan⁴ While maternal behavior is essential for the survival of mammalian newborn offspring, more than 95 % of mammalian species rarely display males paternal. Male mice are not paternal without the sensitization to pup stimuli. We found that 77 % of socially isolated virgin males showed paternal crouching to the pups, 13 % committed infanticide, and the remaining of 10 % ignored pups, whereas no males kept in their littermates displayed paternal behavior. Then, we placed other virgin males alone in two-compartment cages divided by doubled opaque walls with alternated small holes. This equipment prevented physical contact and visibility but not odor and sound, that is, they could smell and hear each other. After 3 weeks housed each other in this equipment, no males displayed crouching behavior, suggesting that the isolated housing environment facilitates paternal behavior. We concluded that the social deprivation, especially, olfactory cues disinhibit the brain circuit for parental care in the male mice. In order to investigate the mechanisms of the brain for this phenomenon, we compared the gene expression by the cDNA microarray analysis using the specimen obtained from the preoptic area and the paraventricular nucleus in the hypothalamus of virgin males between which were kept in solely and were in their littermates after the pups exposure. We further discuss the genes responsibilities for induction of paternal crouching behavior change toward pups.

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