シンポジウム（Symposium）

Symposium Neurobiology of emotional communication in rodents シンポジウム Neurobiology of emotional communication in rodents

7月26日（金）8:30～9:00　第6会場（朱鷺メッセ　2F　201A） 2S06m-1 ラットにおける警報フェロモンと安寧フェロモン Yasushi Kiyokawa（清川泰志）東京大院農獣医動物行動 The neuroscience community has become increasingly aware that animals can change their behavior depending on the level of stress in conspecifics. Such empathetic abilities are extremely attractive for researchers, which have led to establish numerous experimental models even in rodents observing helping behavior, consolation behavior, emotional contagion, vicarious fear, observational fear learning, and fear conditioning by proxy. Although it is difficult to clarify whether the empathetic behaviors in these models are based on higher brain functions, it is obvious that there is communication that triggers empathetic behaviors in the focal animals. In this talk, I would like to introduce two types of olfactory communication in rats, which augments anxiety responses or ameliorates fear responses in recipients. In alarm pheromonal communication, rats release 4-methylpentanal and hexanal from their perianal region when they are stressed. These molecules activate the anxiety circuit, including the bed nucleus of the stria terminalis, when 4-methylpentanal and hexanal are simultaneously detected by the vomeronasal and main olfactory systems, respectively. Consequently, recipient rats show a variety of anxiety responses, depending on the situations. In appeasing pheromonal communication, nonstressed rats release an appeasing pheromone, which is detected by the main olfactory system of recipient rats. When detected, this pheromone activates the posterior complex of the anterior olfactory nucleus and, as a result, suppresses the lateral amygdala. Thus, the conditioned fear responses elicited by auditory conditioned stimulus are ameliorated in recipient rats and causes social buffering. These findings clearly demonstrate that an olfactory signal alone can be sufficient to mediate empathetic behaviors. We believe that the interpretation of phenomenon without presuming higher brain functions is paradoxically the best way to fairly evaluate focal animals' empathetic abilities and accentuate the existence of higher brain functions.		7月26日（金）9:00～9:30　第6会場（朱鷺メッセ　2F　201A） 2S06m-2 Oxytocin-Dependent Emotion Recognition in Mice Francesco Papaleo（Papaleo Francesco） Istituto Italiano di Tecnologia Recognition and discrimination of other's emotions is a fundamental ability that influences development, survival and evolution of animals. Oxytocin (OXT) has been implicated in recognition of emotions. However, the action of endogenous OXT pathways and the brain mechanisms involved in recognition of emotions remains elusive. Here, we developed a new behavioral assay to measure mice ability to discriminate unfamiliar conspecifics based on either positive or negative emotional states. Using a combination of anatomical, genetic, and chemogenetic approaches we investigated the contribution of endogenous OXT signaling in mice emotion recognition. We show that mice are able to recognize and discriminate emotions in conspecifics, by a process that is distinct from sociability and emotion contagion. We found that OXT-ergic projections from the hypothalamus to the central nucleus of the amygdala (CeA) are necessary for the recognition of both positive and negative emotional states, while OXT release into the nucleus accumbens, prefrontal cortex, and hippocampal CA2 is dispensable. In agreement, virally-mediated enhancement of OXT signaling in the CeA is sufficient to rescue emotion recognition deficits in a genetic mouse model of cognitive liability. Our findings demonstrate that CeA OXT signaling plays a key role in emotion recognition in physiological and pathological conditions.

7月26日（金）9:30～10:00　第6会場（朱鷺メッセ　2F　201A） 2S06m-3 Behavioral and Neural Dynamics of Prosocial Behavior in Rats Julen Hernandez-Lallement（Hernandez-Lallement Julen）¹，Valeria Gazzola（Gazzola Valeria）^1,2，Christian Keysers（Keysers Christian）^1,2 ¹Social Brain Lab, Netherlands Institute of Neuroscience, The Netherlands ²Dept. of Psychology, Univ. of Amsterdam, Amsterdam, The Netherlands Showing what is commonly referred to as prosocial behaviors is appreciated and rewarded in human society, whereas anti-social actions often lead to isolation and reclusion and have a high societal cost. Understanding the neural mechanisms triggering prosocial choices would greatly benefit from rodent models that allow us to measure and manipulate brain activity with great precision. Here, we therefore present a rodent model of empathy-driven prosocial behavior, suited for cutting-edge neuroscientific manipulations. In this task, rats first developed a preference for a higher value option in a binary choice situation. In a second phase, choosing that option led to a punishment to an adjacent conspecific. Accordingly, if other's distress carries a negative value for at least some individuals, they should switch preference away from the formerly preferred option now harming others. Individual differences in switching can then reveal individual differences in the value associated to the pain of others. In this talk, I will present recent evidence of empathy-driven prosocial behavior. I will show that rats behave prosocially, a purposive behavior not explained by overall stress levels. I will present evidence suggesting that fear experience, while a powerful primer of prosocial behavior, is not required for its emergence. Finally, I will discuss a possible role of the ACC in prosocial behavior, in line with recent findings suggesting that this structure is involved in vicarious emotions.		7月26日（金）10:00～10:30　第6会場（朱鷺メッセ　2F　201A） 2S06m-4 The neural basis of social choice in rats Sander van Gurp（van Gurp Sander）¹，Marijn van Wingerden（van Wingerden Marijn）^1,2，Douman Seidisarouei（Seidisarouei Douman）¹，Mireille van Berkel（van Berkel Mireille）¹，Tobias Kalenscher（Kalenscher Tobias）¹ ¹Heinrich-Heine University, Duesseldorf, Germany ²Tilburg University, Tilburg, the Netherlands Rats are highly social animals living in large groups characterized by hierarchies, with a rich and complex social behavior repertoire. In the lab, rats have been shown to act pro-socially and perform helping behavior. These results seem to suggest that rats place a value on the well-being of, or outcomes delivered to their peers. If so, this process of social valuation should be observable in tasks sensitive to value estimation and manipulation. We aimed to quantify these social preferences with a range of behavioral paradigms. Adapting the 3-chambered social maze, we examined and quantified rats' social preferences when choosing to spend time investigating a conspecific or a non-social outcome, equating one in terms of the other. Using reinforcement learning paradigms, we examined whether social value can unblock learning about cues that predict reward delivery to others. We have found that, indeed, rats act as if trading off social reward and non-social reward based on their relative appetitive strength. Furthermore, we have found that social outcomes can unblock reinforcement learning, suggesting that rats process social value as valuable to themselves. Rats in these paradigms emit ultrasonic vocalisations (USVs), a prime candidate signal for transmitting social value. Playback of USVs results in Dopamine (DA) release, making the dopamine-producing cells in the VTA, that are involved in socially motivated (reward) seeking behavior in turn a candidate for representing such value signal. Using single-cell electrophysiology, we recorded activity from VTA-DA producing cells during playback of USV and indeed found a subset of cells responding differentially to the valence of the USV playback.