感覚情報の統合と情動行動表出の脳神経基盤
Neural mechanisms for integration of sensory information and a pathway to emotion and behaviour
S1-3-3-1
ゼブラフィッシュが好きな匂いと嫌いな匂い:嗅覚行動の神経回路基盤
Olfactory neural circuitry in zebrafish: Does it smell good, bad, or sexy?

○吉原良浩1
○Yoshihiro Yoshihara1
独立行政法人理化学研究所シナプス分子機構研究チーム1
Laboratory of Neurobioligy of Synapse, Riken Brain Science Institute1

Zebrafish has become one of the most useful model organisms in neurobiology. In addition to its general advantageous properties (external fertilization, rapid development, transparency of embryos, etc.), zebrafish is amenable to various genetic engineering technologies such as transgenesis, mutagenesis, gene knockdown/knockout, and transposon-mediated gene transfer. Our transgenic approach unraveled two segregated neural pathways originating from ciliated and microvillous olfactory sensory neurons (OSNs) in the olfactory epithelium to distinct regions of the olfactory bulb, which likely convey different types of olfactory information (e.g. pheromones and odorants). Furthermore, the two basic principles (one neuron - one receptor rule and axon convergence to target glomeruli) are essentially preserved also in zebrafish, rendering this organism a suitable model vertebrate for the olfactory research. In this talk, I will summarize recent advances in our knowledge on functional architecture of the zebrafish olfactory circuits mediating various odor-induced behaviors. In particular, I will focus on molecular genetic dissection of the neural elements involved in the attraction to food odorants, the aversion from alarm pheromones, and the social response to sex pheromones.
S1-3-3-2
線虫の味覚可塑性とその機構
Gustatory plasticity and underlying mechanisms in C. elegans

○飯野雄一1, 國友博文1, 大野速雄1, 佐藤博文1, 佐藤陽介1, 土屋純一1, 山田康司1, 加藤紳也1, 内藤泰樹1, 富岡征大1
○Yuichi Iino1, Hirofumi Kunitomo1, Hayao Ohno1, Hirofumi Sato1, Yohsuke Satoh1, Jun-ichi Tsuchiya1, Koji Yamada1, Shinya Kato1, Yasuki Naito1, Masahiro Tomioka1
東京大学・大学院理学系研究科1
Department of Biophysics and Biochemistry, The University of Tokyo1

The nematode C. elegans is an excellent model system to study how a neural network recognizes the environmental chemical signals and how it regulates the navigation behavior based on the memory of previous experiences.
Worms determine the two-dimensional concentration gradient of salt, NaCl, by using a single chemosensor at the head, and migrate towards higher, or lower, salt concentrations. Importantly, worms memorize the salt concentration at which they were cultivated with ample food and migrate to this concentration range when placed on a salt concentration gradient. They achieve this directional migration by using a combination of two behaviors, "pirouette" and "weathervane". By quantification of these behaviors, we found that experience-dependent plasticity of chemotaxis is achieved by reversal of these elementary behaviors depending on whether current salt concentration is higher or lower than the memorized concentration. Neural activities of a small circuit of sensory neurons and interneurons show dramatic changes that can partially explain this behavioral switching.
On the other hand, when the worms were starved, they now avoid the salt concentration that they have experienced in the absence of food. The switch of behavior by starvation is mainly mediated by the insulin/PI 3-kinase pathway, which acts in a single chemosensory neuron ASER. We found that the newly found isoform of the worm insulin receptor DAF-2, DAF-2c, is preferentially localized to the synapse-rich axonal region of the ASER neuron. This localization increased by starvation. Furthermore, DAF-2c was found transported to the axon by the kinesin-1 complex, and this transport was negatively regulated by MAP kinase. We also found that the starvation-dependent learning involves down-regulation of synaptic transmission from the sensory neuron. We propose that this regulation of insulin receptor localization is a key component of the starvation-dependent salt chemotaxis learning.
S1-3-3-3
温度センサーの可塑性と温度情報の統合機構
Plasticity of thermosensors and integration of temperature information

○富永真琴1
○Makoto Tominaga1
自然科学研究機構 岡崎統合バイオサイエンスセンター1, 総合研究大学院大学 生理科学2
Division of Cell Signaling, Okazaki Institute for Integrative Bioscience1, Department of Physiological Sciences, The Graduate University for Advanced Studies2

Ambient temperature can be precisely detected either by skin keratinocytes or sensory neurons where thermosensitive TRP channels are involved in the function. The detected temperature information is integrated through the ascending pathways and is affected by many factors. In addition, ambient temperature information can be modulated dynamically at the periphery through the changes in the function of thermosensing molecules, TRP channels. I would like to summarize the recent progress of the research of thermosensitive TRP channels expressed in skin keratinocytes and sensory neurons.
S1-3-3-4
感覚情報と情動行動をつなぐ神経基盤理解のためのアプローチ
Approach for understanding the mechanism linking multimodal information to emotional behavior

○松尾直毅1,2
○Naoki Matsuo1,2
京都大学白眉センター1, 科学技術振興機構さきがけ2
The HAKUBI Center, Kyoto University1, PRESTO, JST2

Multimodal sensory information triggers and modifies emotional behaviors. However, it remains unclear how the information is integrated and represented in the brain. A prevailing hypothesis suggests that information is encoded by a cooperative activity of specific subset group of neurons. However, identifying the neurons supporting a given information is challenging because these neuronal ensembles are likely sparsely distributed in the brain.
Contextual fear conditioning is a suitable model for studying the neuronal mechanism linking multimodal sensory information to emotional responses. Several previous studies including ours detected neurons whose activity is correlated with contextual fear-memory encoding. However, correlative studies do not address whether these neurons are essential components of the fear-memory engram. Utility of the cfos-tTA transgenic mice allows us to visualize and manipulate a neuronal activity in a specific subset of neurons that were activated by a fear-memory encoding. We have specifically stimulated or suppressed the activity of those sparsely activated neurons by DREADD (Designer Receptors Exclusively Activated by Designer Drug) system or tetanus toxin, and examined whether subsequent fear expression was affected. These studies would reveal a causal link between neuronal activity of a specific neuronal ensemble and a given information, and provide us a great insight about the representation of the external world in the brain.
S1-3-3-5
痛みによる不快情動生成における分界条床核の役割
Role of the bed nucleus of the stria terminalis in pain-induced negative emotion

○南雅文1
○Masabumi Minami1
北海道大学薬学薬理学研究室1
Dept Pharmacal, Grad Sch Pharm Sci, Hokkaido Univ1

Pain is an unpleasant sensory and emotional experience. The neural systems underlying the sensory component of pain have been studied extensively, but we are only beginning to understand those underlying its emotional component. The bed nucleus of the stria terminalis (BNST) has been implicated in stress responses and negative affective states, such as anxiety, fear, and aversion. In the present study, we first examined the role of the CRFergic transmission within the dorsolateral part of the BNST (dlBNST) in pain-induced aversion in male Sprague-Dawley rats. In vivo microdialysis demonstrated the increased release of CRF within the dlBNST by intraplantar formalin injection. Intra-dlBNST injection of CRF receptor antagonists dose-dependently attenuated the formalin-induced conditioned place aversion (CPA) without reducing nociceptive behaviors. Intra-dlBNST injection of CRF dose-dependently produced CPA even in the absence of noxious stimulation. Taken together, these results reveal that enhanced CRFergic transmissions within the dlBNST are important for the negative emotional component of pain. Next, in order to address cellular mechanisms for this effect of CRF, we examined the effect of CRF on neuronal activity in dlBNST neurons using a whole-cell patch-clamp recording. We found that CRF modulated the resting membrane potential in a particular type of neurons, type II neurons, in the dlBNST. To clarify the neuronal circuit(s) involved in pain-induced aversion, we characterized VTA-projecting BNST neurons using combined neurotracing and histochemical techniques. The major BNST-VTA projection originates from GAD67-expressing GABAergic neurons in the BNST, and preferentially targets GABAergic interneurons in the VTA, suggesting the disinhibitory control of VTA dopaminergic neurons by BNST-VTA projection. I will discuss the neuronal circuits for pain-induced negative emotion.
S1-3-3-6
マウスの社会行動を司る嗅覚と聴覚情報
Chemical and auditory senses regulate mice social behavior

○菊水健史1, 浅場明莉1, 岡部祥太1, 永澤美保1, 茂木一孝1
○Takefumi Kikusui1, Akari Asaba1, Shota Okabe1, Miho Nagasawa1, Kazutaka Mogi1
麻布大学獣医学部1
School of Veterinary Medicine, Azabu University1

Animals including humans use multisensory cues for initiation of social behavior. In mice, chemical and auditory cues have been demonstrated to induce social behavior, such as sexual and parental behavior. However, there is little challenge how on these cues are integrated and regulate the social behaviors. We examined the multisensory regulation of social behavior using 2 models, namely maternal behavior and sexual partner preference. First, we investigated whether pup odor and pup ultrasonic vocalizations (USVs) synergically stimulated maternal response in mother C57BL/6 mice using two-choice tests. The mothers did not approach reproduced pup USVs or pup odor those were sorely presented. However, simultaneous presentation of pup USVs and odor induced a specific approach response.C-fos positive cells in the bed nucleus of stria terminalis, medial preoptic area, central nucleus of amygdala, and basolateral amygdala,were found to be significantly increased, following the simultaneous presentation of pup USVs and odor, suggesting that these nuclei are involved in multimodal processing related with maternal behavior. Secondly, song preference of C57BL/6 or BALB/c female mice were monitored by two-choice test. C57BL/6 females preferred BALB/c male songs, whereas BALB/c females preferred C57BL/6 male songs, especially in females subjected to male sexual odorant cues. These results suggest that female mice can discriminate the characteristics of male songs and prefer the songs of mice of different strains under the stimulation of male odorants. These data suggest that social cue itself might not have privileged property for initiating social behavior, instead perceptual context, in which mice accepted various cues simultaneously, and multimodal processing seemed to be rather important for initiation social behavior.
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