ナカムラ　カエ   NAKAMURA KAE   中村　加枝    所属   関西医科大学  生理学講座    職種   教授
言語種別	日本語
発表タイトル	サル背側縫線核における報酬および嫌悪刺激の情報表現 Neuronal coding of rewarding and aversive stimuli in the primate dorsal raphe nucleus.
会議名	第33回　日本神経科学大会
学会区分	全国規模の学会
発表形式	ポスター掲示
講演区分	一般
発表者・共同発表者	◎Hayashi, K,. Nakao,K., Okada,O., Kobayashi,Y., Nakamura, K.
発表年月日	2010/09
開催地 （都市, 国名）	神戸
概要	Neuronal activity in the dorsal raphé nucleus (DRN), a major source of serotonin, is modulated by the received reward size. To investigate whether DRN neurons code rewarding or aversive stimuli and/or positive or negative prediction error, we recorded single-unit activity in the DRN of two monkeys performing the trace conditioning task. This task consisted of two blocks with distinct contexts. In the appetitive block, liquid reward was used as an unconditioned stimulus (US). In the aversive block, air-puff directed at the monkey face was used as a negative US. In both blocks, three visual stimuli (conditioned stimuli: CSs) were paired with the US, with probabilities of 100, 50 and 0%, respectively. To confirm that monkeys learned the association of each specific CS with the US, we monitored licking behavior and anticipatory eye blinking. In 50 and 0% trials, tone was presented as a neutral stimulus in the absence of reward or air-puff. We recorded 211 task-related neurons. It was found that DRN neurons responded to the CSs in the appetitive block more often than in the aversive block; 38% (n=81) responded to the rewarding CS with 100% probability, while 9% (n=19) responded to the aversive CS with 100% probability. Among them, 13 neurons responded to both rewarding and aversive CSs. Many DRN neurons also responded to the USs (n=176); either to reward only (n=35), to air-puff only (n=57) or to both (n=84). In the appetitive block, reward-related activity was modulated by its probability with stronger response to the unpredicted than the predicted US. In the aversive block, short-latency response to air-puff delivery was frequently observed regardless of the CS-US predictability. These results suggest that the primate DRN codes information about both rewarding and aversive stimuli, and some DRN neurons exhibited activity similar to reward prediction error reported for dopamine neurons.