数秒範囲の時間評価における神経基盤

―背側線条体の役割―

抄録

Previous studies have examined the neural mechanisms of interval timing (i.e., time perception in the seconds-to-minutes range). Some studies have demonstrated that silencing the dorsal striatum abolishes optimal performance during interval timing tasks. This finding suggests the dorsal striatum has an important role in interval timing. However, research has also demonstrated that the dorsal striatum is important for performing actions. Thus, the possibility that silencing the dorsal striatum affects the performance of actions during tasks rather than interval timing cannot be ruled out. To address this issue, we examined the role of the dorsal striatum in a temporal discrimination task and tone pitch discrimination task. Rats were presented various pitches of tones for various durations and were then required to press one of two levers. They would finally receive rewards if their responses were correct. These tasks were identical, except for the dimension of the required discrimination. Pharmacological inactivation of the dorsal striatum impaired performance in the temporal discrimination task, but not in the tone pitch discrimination task. This finding suggested the specific role of the dorsal striatum in interval timing.