若手道場口演（Wakate Dojo）

Wakate Dojo Emotion, Motivation, Learning, Consciousness 2 若手道場口演情動・動機づけ・記憶・意識2

7月26日（金）16:10～16:30　第10会場（万代島ビル　6F　会議室） 2WD10ba2-1 Tbx1遺伝子ヘテロ欠損自閉症モデルマウスにおけるコミュニケーション能力の解析 Risa Kato（加藤梨沙）¹，Akihiro Machida（町田暁洋）¹，Kensaku Nomoto（野元謙作）¹，Noboru Hiroi（廣井昇）²，Kazutaka Mogi（茂木一孝）¹，Takefumi Kikusui（菊水健史）¹ ¹麻布大学院獣医学研究科 ²アルベルト・アインシュタイン医学校 Tbx1 genetic variants are associated with autism spectrum disorders in humans. We have shown that Tbx1 heterozygous (Tbx1 HT) mice emit atypical pup ultrasonic vocalizations (pup USVs). However, it is not fully understood how the deficiency of this gene affects social communication. To address this question, we first examined maternal approach behaviors to atypical Tbx1 HT pup USVs. We played back recorded pup USVs and examined the responses of wild-type (WT) mothers. Our data showed that atypical Tbx1 HT pup calls did not elicit WT mothers' approach behaviors even though WT mothers had raised Tbx1 HT pups. These results suggest that WT mothers do not respond atypical Tbx1 pup USVs regardless of the presence or absence of experiences raising Tbx1 HT pups, probably because social interactions with Tbx1 HT pups were less rewarding to WT mothers. To investigate if social interactions with Tbx1 HT juveniles are also less rewarding, we evaluated reinforcing value of social interactions among Tbx1 HT and WT littermates using social conditioned place preference (SCPP). SCPP was composed of test sessions (pre and post) and conditionings (social and isolated). The apparatus was divided into two compartments. Each compartment contained a different type of bedding. First, mice spent time freely exploring each compartment during a pre-test session for 30 minutes. After this, mice were confined to one type of bedding with a WT or Tbx1 HT littermate during a social conditioning for 24 hours, and to a different type of bedding without a littermate during an isolated conditioning for 24 hours. Following the completion of these conditionings, all mice were subjected to a free exploration as a post-test session for 30 minutes. The more rewarding social interactions are, the higher reinforcing values are. That is why mice spend more time in the social conditioned compartment during a post-test session compared to a pre-test session. Our data showed that the reinforcing value of Tbx1 HT males to WT males was lower compared to that of WT males to WT males. The reinforcing value of both Tbx1 HT and WT males to Tbx1 HT males tended to be lower compared to that of WT males to WT males. Overall, our findings suggest that Tbx1 deficiency alter social communication not only between mothers and pups but also among juveniles.		7月26日（金）16:30～16:50　第10会場（万代島ビル　6F　会議室） 2WD10ba2-2 げっ歯類が見るものは聞いているものである Yuki Ito（伊藤優樹），Ryo Sato（佐藤涼），Yu Masago（真砂裕），Shizuko Hiryu（飛龍志津子），Kohta I Kobayasi（小林耕太）同志社大院生命医科学 When two sensory modalities receive conflicting information, the perception of one modality is sometimes modified to align with the other modality. For example, when a brief flash is accompanied by two brief sounds, the single flash is often perceived as two flashes. This phenomenon is called ""sound-induced flash illusion"" and these illusions by sensory integration demonstrate how human perceived the multi-sensory environment in a tightly integrated manner, and the illusions serves as a key to reveal how and where the information from different sensory modalities is integrated in the brain, and subsequently generate our perception. It is, however, unclear if nonhuman animals experience the sound-induced flash illusion. We investigated whether sound-induced flash illusion occurred in Mongolian gerbil, one of the standard laboratory rodent species. We used the novel object recognition paradigm to evaluate the naturally developed sensory potential of the gerbils. An object equipped with a LED was set in a behavioral arena, and a loudspeaker was fixed above the arena. The gerbils were first familiarized with a repetitive single flash. In the test trial, the presentation of paired flashes caused a significant increase in exploration, confirming that the NOR paradigm is suitable for evaluating their perception of stimulus temporal pattern (i.e., number of flashing). In a subsequent experiment, in the familiarization trials, paired tone bursts and a single flash were repeatedly presented with a stimulus-onset asynchrony (SOA) of 255 ms. Two types of SOA (0 and 100 ms) were then introduced in test trial. The 100 ms SOA was longer than the integration window reported in human research, and our result showed that only the 0 ms SOA increased the exploratory behavior of the gerbils. These results suggest that the gerbil's visual perception is altered when a contradictory sound is presented simultaneously, and that sensory integration underlying the sound-induced flash illusion may be shared across mammals. While we still need to conduct the more tightly controlled behavioral task as operant conditioning, the gerbil will give us an opportunity to investigate the detailed neural mechanism of audio-visual integration.

7月26日（金）16:50～17:10　第10会場（万代島ビル　6F　会議室） 2WD10ba2-3 ショウジョウバエ幼虫の光回避行動を規定する神経回路 Natsuko Omamiuda-Ishikawa（大豆生田−石川夏子），Moeka Sakai（酒井萌花），Kazuo Emoto（榎本和生）東京大院理生物科学 Animals typically avoid noxious stimuli with stereotyped escape behavior.For instance, Drosophila larvae receive blue light as noxious stimuli and show escape behavior consisting of stereotyped behavioral repertoire including rapid forward locomotion, head-casting, turning and backward locomotion. It is known that light-induced escape behavior is mediated by two distinct sensory pathways: class IV dendritic arborization (C4da) sensory neurons on body wall and photoreceptor neurons on a dorsomedial position in the anterior region, yet how these pathways are coordinated to evoke efficient escape behavior in the circuit level remains elusive. Here we identify two distinct pairs of neurons, designated MDN neurons and STG neurons which are located in the larval brain and suboesophageal zone respectively, that evoke backward locomotion upon optogenetic activation. Our anatomical and functional analysis indicates that STG neurons are directly upstream of MDN neurons and send excitatory signals to MDN neurons. Further functional analysis indicates that STG neurons are downstream of C4da sensory neurons, but not photoreceptor neurons. On the other hand, MDN neurons receive input from not only from C4da neurons via STG neurons but also photoreceptor neurons. It is consistent with the result that MDN neurons, but not STG neurons, are required for noxious light-induced backward locomotion. Combining these results, our findings suggest that STG neurons are interneurons that specifically medicate noxious information from C4da sensory neurons to MDN neurons. This study thus reveals a neural circuit of noxious light-induced backward locomotion and paves the way to understand the nature and logic of the signals that pass between the brain and redundant sensory circuits.