成体期黒質損傷ラットにおける時間知覚の行動科学的検討 <論文>

We studied the effects of an injection of 6-hydroxydopamine (6-OHDA) into the substantianigra of rats on the performance of timing behavior by using a peak interval (PI) procedure. Rats were trained on a PI 30-s procedure for 30 sessions. Then, subjects were divided into three groups: lesion (n=6), operational sham lesion (n=3) and intact (n=3). After 6-OHDA treatment, subjects were retrained on the PI 30-s procedure for 15 sessions and were checked for their timing behavior. Results indicated that sham and intact groups did not change the performance of timing between pre- and post- operation treatment. In the lesion group, a behavioral change occurred shortly after lesion treatment. They showed a dull curved peak in PI 30-s and peak time showed an in accuracy of 30-s. However, the lesion group recovered their performance following repeated training for 15 sessions. It is suggested that we should further investigate the durability of the 6-OHDA, as well as conduct histological analysis of the striatum, which is the dopamine (DA) projection ahead of the substantianigra. Such investigations would enable the identification of possible relationships between the function of substantianigra and time perception.