嗅覚、味覚、化学感覚 Olfaction, Taste, Chemical Senses
P2-2-110 鳩における前梨状皮質の投射様式 Fiber connections of the prepiriform cortex in the pigeon ○阿閉泰郎1 ○Yasuro Atoji1 岐阜大学応用生物科学部獣医解剖学1 Lab Vet Anat, Gifu Univ, Gifu1 The olfactory system in birds consists of the olfactory bulb, anterior olfactory nucleus, prepiriform cortex (CPP), nucleus taeniae of the amygdala (TnA), and piriform cortex. I reported at a previous meeting (2012) that the olfactory bulb projects heavily to CPP. The present study was examined efferent and afferent fiber connections of pigeon CPP by a tract-tracing method. When cholera toxin B (CTB) was injected into CPP, CTB-labeled neurons were numerously distributed in whole CPP, densocellular part of the hyperpallium (HD), tenia tecta, anterior olfactory nucleus, piriform cortex, and dorsolateral corticoid area (CDL). The olfactory bulb contained several CTB-labeled neurons in the mitral cell layer. In TnA, CTB-labeled neurons were seen in rostral portion under the occipito-mesencephalic tract at levels of the anterior commissure, but caudal to it they were not found. When biotinylated dextran amine (BDA) was injected into CPP, pathways and terminals of labeled fibers basically showed mirror image of CTB labeling in a contralateral side. BDA-labeled fibers were divided into two routes. First, a compact fiber bundle runs in CPP caudally to the piriform cortex on lateral surface of the telencephalon. On the way, several loose bundles are branched to the medial striatum, olfactory tuberculum, and septum at rostral region, to rostral TnA at middle region, and at caudal region to lateral portions of arcopallium and caudal nidopallium and dorsally to CDL and lateral hippocampal formation. A few BDA-labeled fibers appeared to go down into the hypothalamus via occipito-mesencephalic tract. Secondly, a large loose bundle starts to go medio-ventrally or medially. The loose bundle travels to the olfactory bulb, anterior olfactory nucleus, tenia tecta, and HD. Main projections of pigeon CPP extend wider than those of the olfactory bulb and CPP is a relay station to limbic system.	P2-2-111 コモンマーモセット嗅球の構造 Structure of the marmoset olfactory bulb ○徳野博信1, 守屋敬子1, 田中いく子1, 海津敬倫1, 市川眞澄2 ○Hironobu Tokuno1, Keiko Moriya-Ito1, Ikuko Tanaka1, Yoshitomo Umitsu1, Masumi Ichikawa2 東京都医学総合研究所・脳構造研究室1, 東京都医学総合研究所・基盤技術研究センター2 Lab Brain Struct, Tokyo Met Inst of Med Sci, Tokyo1, Bas Tech Res Cent, Tokyo Met Inst of Med Sci, Tokyo2 The common marmoset (Callithrix jaccus) is a small-sized New World monkey, which is attracting growing attention in the field of neuroscience. Several brain atlases of the marmoset have been published in recent years. However, the olfactory bulb has not been described in these atlases. Thus we have examined cyto- and chemoarchitecture of the marmoset olfactory bulb in the present study. Adult common marmosets were deeply anesthetized and perfused through the heart with 4% paraformaldehyde solution. Coronal or parasagittal sections were made with a freezing microtome. Nissl-stained sections were used for cytoarchitectonic analysis. For chemoarchitectonic analysis, immunostained sections were prepared using antibodies against calcium binding proteins or SMI-32. They were then incubated with a biotinylated secondary antibody against primary antibody, and incubated with an ABC-elite kit (Vector). The sections were processed with DAB and nickel chloride. The sections were finally scanned with a Mirax Scan to obtain high resolution zoomable digital images. In addtion, input and output organization of the olfactory bulb was analyzed using tract tracing techniques with biotinylated dextran amine and cholera toxin B subunit.
P2-2-112 線虫における交差順応 Cross modality adaptation in Caenorhabditis elegans ○設樂久志1, 小林純也1, 棚元亮1, 堀田耕司1, 岡浩太郎1 ○Hisashi Shidara1, Jyunya Kobayashi1, Ryo Tanamoto1, Kohji Hotta1, Kotaro Oka1 慶應大院・理工・生命1 Dept Bio and Info, Fac of Sci and Tech, Keio Univ1 Caenorhabditis elegans is naturally exposed to the various sensory modality stimulations: odor, gustatory and temperature. C. elegans is known to dissect these modalities by specific sensory neurons; odor cues sensed by AWA and AWC respectively, gustatory by ASEL. These various cues lead worms to decide their behavior. Previous reports have clarified the neural functions and circuits related with just single sensory modality. However, it is unknown how different modality stimulations influence each other (cross modality). Here, we revealed the adaptation to one sensory modality affects another modality, which we named the cross modality adaptation.First, we checked worms showed the cross modality adaptation by behavioral assay. We investigated chemotaxis index (C.I.) for volatile cues of worms exposed to Mg2+ for adaptation in 5 min in advance. When worms are conditioned to Mg2+, C.I. to IAA or DA decreased as much as conditioned to IAA or DA.To understand the cross modality adaptation further, we focused on AIY interneuron because this neuron is related with the adaptation in 5 min (early adaptation) and be received neural projection from various sensory neurons including AWA, AWC and ASEL. We expressed phototaxis red fluorescent protein, KillerRed (Bulina et al., 2006), on AIY, which generates reactive oxygen species (ROS) upon green light irradiation. This technique enables us to prepare many worms with AIY defective for population assay. The defective worms did not show the cross modality adaptation, indicating AIY is necessary for the adaptation.Finally, we checked Ca2+ dynamics of AIY before and after the cross modality adaptation by Ca2+ imaging. Although in pre-adaptation intercellular Ca2+ in AIY increased after odor stimulation, it showed no response after adaptation with Mg2+. These results also suggested that AIY is necessary for the cross modality adaptation.	P2-2-113 腹側淡蒼球δ-オピオイド受容体の阻害によって甘味溶液の摂取量が増加し、嗜好性が上昇する Blockade of delta-opioid receptors in the ventral pallidum induces increase in the intake and palatability of sweet taste solution in rats ○乾賢1, 志村剛1 ○Tadashi Inui1, Tsuyoshi Shimura1 大阪大学　大学院人間科学研究科　行動生態学講座　行動生理学研究分野1 Division of Behavioral Physiology, Department of Behavioral Sciences, Graduate School of Human Sciences, Osaka University, Osaka, Japan1 The ventral pallidum (VP) receives enkephalinergic fiber projections from the nucleus accumbens (NAc). Although the NAc is well known to play a critical role in reward and taste palatability, the role of the enkephalinergic innervation from the NAc to VP in taste palatability and ingestive behavior still remains unclear. Therefore, we examined the effects of microinjection of an antagonist of delta-opioid receptors, which has enkephalin as its endogenous ligand, into the VP on the intake (Exp. 1) and palatability (Exp. 2) of saccharin solution. Furthermore, we tested whether drug injection affects taste palatability of conditioned aversive saccharin (Exp. 3). All rats were implanted with guide cannulae for drug injections. They were trained to drink water from a bottle for 20 min (Exp. 1) or via an intraoral cannula for 3 min (Exp. 2 and 3). In Exp. 1 and 2, the rats were injected with delta-opioid receptors antagonist naltrindole (0, 10 or 100 ng) before the presentation of a 5 mM saccharin on every three days. In Exp. 3, the rats received a pairing of a 5 mM saccharin with an i.p. administration of a 0.15 M lithium chloride. Three days after the conditioning, the naltrindole injection was followed by the saccharin presentation. We measured the intake volume (Exp. 1) or number of ingestive and aversive taste reactivity responses (Exp. 2 and 3). In Exp. 1, the microinjection of the 10 ng naltrindole resulted in significantly larger intake of saccharin solution than the 0 ng. Exp. 2 revealed that the rats injected with 10 ng naltrindole expressed significantly greater number of ingestive taste reactivity responses. In Exp. 3, we found that the 10 ng naltrindole decrease aversive taste reactivity responses to the saccharin solution. These results suggest that the blockade of delta-opioid receptors in the VP increases the palatability of saccharin, so as to facilitate it's consumption. In addition, we showed that the drug treatment attenuate conditioned taste aversion.
P2-2-114 CALHM1イオンチャネルが味蕾における甘味・苦味・うまみ受容時のプリン作動性神経伝達を担っている Purinergic neurotransmission of sweet, bitter and umami tastes in the taste bud by CALHM1 ion channel ○樽野陽幸1,2, 應本真4, 松本一郎4 ○Akiyuki Taruno1,2, Valerie Vingtdeux3, Ang Li2, Zhongming Ma2, Makoto Ohmoto4, Ichiro Matsumoto4, Sze Leung5, Maria Abernethy5, Gennady Dvoryanchikov6, Mortimer M. Civan2, Nirupa Chaudhari6, Goran Hellekant55, Michael G. Tordoff4, Philippe Marambaud3, J. Kevin Foskett2 京都府立医科大院・医・細胞生理1, ペンシルバニア大・医・生理2, ファインスタイン医学研究所3, モネル化学感覚研究所4, ミネソタ大ダルース校・医・生理薬理5, マイアミ大・医・生理生物物理6 Dept Mol Cell Physiol, Kyoto Pref Univ Med, Kyoto1, Dept Physiol, Univ Pennsylvania, Philadelphia, PA, USA2, Feinstein Inst for Med Res, Manhasset, NY, USA3, Monell Chem Senses Ctr, Philadelphia, PA, USA4, Dept Physiol Pharmacol, Univ Minnesota Duluth, Duluth, MN, USA5, Dept Physiol Biophys, Miller Sch Med, Univ Miami, FL, USA6 Taste buds (TB), composed of three distinct types of cells (type I, II and III), sense taste compounds and transmit signals to afferent gustatory neural pathways. Recognition of sweet, bitter and umami tastes requires non-vesicular release from type II cells of adenosine 5'-triphosphate (ATP) which acts as a neurotransmitter to activate afferent neural pathways. However, how ATP is released to fulfill this function is uncertain. In the present study, we show that a recently identified ion channel, calcium homeostasis modulator 1 (CALHM1), is an essential component for taste-evoked ATP release from sweet/bitter/umami-sensing type II TB cells. Calhm1 is expressed in mouse TB but not in surrounding epithelium. The co-expression of Calhm1 and Trpm5, and loss of Calhm1 signal in TB of Skn-1a-/- mice in which type II cells are developmentally absent, demonstrate that Calhm1 expression is confined to type II cells. Calhm1 KO mice are indifferent to sweet, bitter and umami compounds, whereas sour and salty taste recognition remains mostly normal. Its heterologous expression induces a novel ATP permeability that releases ATP from cells in response to manipulations that activate the CALHM1 ion channel, such as membrane depolarization and a reduction in extracellular Ca2+ concentration. Knockout of Calhm1 strongly reduces voltage-gated currents in isolated type II cells and taste-evoked ATP release from taste buds without affecting the excitability of taste cells to taste stimuli. Thus, CALHM1 is an ATP release channel required for sweet, bitter and umami taste perception as the neurotransmitter (ATP) release pathway.	P2-2-115 内因性レプチンとエンドカンナビノイドが高脂肪食肥満マウスの甘味感受性に及ぼす影響 Modulation of sweet taste sensitivity by endogenous leptin and endocannabinoids in mice with different circulating leptin levels ○仁木麻由1, 上瀧将史1, 大栗弾宏1, 吉田竜介1, 二ノ宮裕三1 ○Mayu Niki1, Masafumi Jyotaki1, Tadahiro Ohkuri1, Ryusuke Yoshida1, Yuzo Ninomiya1 九州大院・歯・口腔機能解析学1 Sect.Oral Neurosci., Grad. Sch. of Dental Sci., Kyushu Univ., Fukuoka, Japan1 The taste organ is a peripheral target for both leptin (Lep), an anorexic mediator and endocannabinoids (ECs), orexigenic mediators. Lep is shown to selectively suppress sweet taste responses in lean mice but not in Lep receptor-deficient db/db mice. In contrast, ECs enhance sweet taste sensitivities in lean mice but not in mice genetically lacking CB1 receptors. However the action of endogenous Lep and ECs on taste responses has not fully been made clear. In this study, we examined expression of related molecules and the effect of antagonists for Ob-Rb (leptin L39A/D40A/F41A : LA) Lep and CB1 (AM251) ECs receptors on the chorda tympani (CT) nerve responses in mice with different serum Lep levels. The results showed that about 40 % of taste cells expressing T1r3 (sweet taste receptor component) coexpressed Ob-Rb. Administration of LA significantly increased sweet taste responses of lean control mice, whereas administration of AM251 did not affect. Moreover the effect of LA on sweet responses gradually decreased with increasing plasma leptin levels, whereas the reverse is true for ECs. These findings suggest a possibility that circulating Lep may act as a modulator in mice that tonically influence basal sweet taste sensitivity, while ECs may become more effective with defects in Lep system.
P2-2-116 行動状態依存的に起こる呼吸リズムと嗅覚情報処理モードの変化 Behavioral state-dependent change in respiration pattern and information processing modes of the olfactory systems in freely behaving rats ○眞部寛之1,2, 森憲作1,2 ○Hiroyuki Manabe1,2, Kensaku Mori1,2 東京大学大学院　医学系研究科　細胞分子生理学1 Dept. Physiol., Grad. Sch. of Med., Univ. of Tokyo, Tokyo1, JST CREST, Japan2 Behavioral states control information processing modes of neuronal circuits in the brain. In the olfactory system, acquisition of the external odor information depends on respiratory rhythms. Because behavioral states controls also respiratory rhythms, information processing modes in the olfactory systems may be tightly coupled with the respiratory rhythms. In the present study, we examined the behavioral state-dependent change in the respiration pattern and information processing modes in the olfactory bulb (OB) and the olfactory cortex of freely behaving animals. We compared the respiration pattern and the neuronal activity pattern in the OB and the anterior piriform cortex (APC) among various behavioral states.Change in the behavioral states accompanied with coordinated change in the respiration pattern and the information processing mode in the OB and the APC. During awake states, local field potentials in the OB and the APC showed respiration-paced fast and slow gamma oscillatory activities. Fast gamma oscillation in the OB and APC coherently occurred at the inspiration phases. Slow gamma oscillation tended to succeed the fast gamma oscillation and occurred mainly at the expiration phases of the slow respiratory rhythms when rats showed eating and resting behaviors. Subpopulation of APC neurons showed respiration phase-locked activity. During slow-wave sleep state, slow-wave and sharp-wave activity occurred in the APC and the OB, whereas the inspiration-paced fast gamma activity was diminished. The respiration phase-locked spike activity in the APC neurons disappeared or reduced significantly during sleep states. These results suggest the behavioral state dependent coordinated change in the respiration pattern and neuronal activity pattern in the OB and the APC.	P2-2-117 嗅結節の深層部は睡眠中に前梨状皮質の同期した入力を受ける The deep layer of olfactory tubercle receives highly synchronized inputs from anterior piriform cortex during slow-wave sleep ○成清公弥1,2, 眞部寛之1,2, 森憲作1,2 ○Kimiya Narikiyo1,2, Hiroyuki Manabe1,2, Kensaku Mori1,2 東京大学大学院 医学系研究科 細胞分子生理学1 Dept Physiol, Univ of Tokyo, Tokyo1, JST-CREST, Japan2 During slow-wave sleep, anterior piriform cortex (APC) neurons are dissociated from external odor inputs by sensory gating and show highly synchronized discharges accompanying sharp waves (SPWs). We previously showed that the APC-SPW-related discharge of APC neurons travel down to olfactory bulb and are involved in the reorganization of bulbar neuronal circuits. However, it is still unknown whether the APC-SPW-related discharges travel to other regions. Olfactory tubercle (OT) is part of ventral striatum and thought to play a key role in reward-directed motivational behaviors. Since the OT receives massive axonal inputs from APC pyramidal cells, we supposed that the OT receives the SPW-associated inputs during slow-wave sleep. In the present study, we examined whether OT neurons receive the SPW-associated synchronized inputs by simultaneous electrophysiological recordings from the APC and OT in freely behaving and urethane-anesthetized rats. Local field potentials in the OT showed SPW-like activities that were in synchrony with the APC-SPWs during slow-wave sleep. Current source density analysis revealed that the current sink of the OT-SPWs was located in the layer II and III of the OT. Single unit recordings showed that a subpopulation of OT neurons discharged in synchrony with the APC-SPWs. Furthermore, correlation analysis of units activities of APC and OT neurons revealed that the discharges of the OT neurons followed those of the APC neurons. These results suggest that APC-SPW-associated synchronized discharges of APC neurons travel to the deep layer of the OT, and drive discharges of OT neurons during slow-wave sleep. We speculate that (1) the generation of SPW-associated synchronized discharges of APC neurons depend on memory-traces stored in the APC during preceding waking periods, and that (2) the highly synchronized inputs play an important role in the reorganization of synaptic connections in the neuronal circuits of the OT during slow-wave sleep.
P2-2-118 マウス三叉神経節における TRPV4 の発現の検討 Investigation of the expression of transient receptor potential vanilloid subtype 4 (TRPV4) in the mouse trigeminal ganglion ○石田雄介1, 中村雪子1, 近藤誠1, 山田貴博1, 島田昌一1 ○Yusuke Ishida1, Yukiko Nakamura1, Makoto Kondo1, Takahiro Yamada1, Shoichi Shimada1 大阪大学大学院　医学系研究科　第一解剖1 Dept Anat, Univ of Osaka, Suita1 Transient receptor potential vanilloid subtype 4 (TRPV4) is a non-selective cation channel and activated by hypotonic stimuli. It is famous that the channel is highly expressed in kidney. It had been reported that the receptor is also expressed in the epithelia of bladder and esophagus, etc. The localization of TRPV4 in these organs seems certain, however, it is controversial whether the channel express in somatosensory neurons. The reason seems to be that the examinations were performed by only immunohistochemical techniques. We investigate the expression of TRPV4 in the mouse trigeminal ganglion by RT-PCR method. Furthermore, we perform in situ hybridization analysis on TRPV4 to examine the expression pattern in the ganglia. In this conference, we show the results and discuss whether TRPV4 express in the mouse trigeminal ganglion.

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