|Budget Amount *help
¥3,300,000 (Direct Cost : ¥3,300,000)
Fiscal Year 2002 : ¥1,200,000 (Direct Cost : ¥1,200,000)
Fiscal Year 2001 : ¥2,100,000 (Direct Cost : ¥2,100,000)
The purpose of the present study was to examine how neuronal activity in the prefrontal cortex is involved in performance of categorized multiple movements. We trained a monkey to perform four movements sequentially, separated by brief waiting periods. In one condition, a visual signal (LED of three different colors) indicated what movement to be performed. In the other condition, correct sequences of fore movements had to be remembered. EMG analyses showed that magnitude of muscle activities were equal in the two conditions. Activity change in forelimb muscle were not detectable during waiting periods. Animal was performed 11 kinds of multiple movements, which are categorized in three patterns; mono-series type (push-push-push-push, pull-pull-pull-pull, turn-turn-turn-turn), alternate series type (push-turn-push-turn, pull-turn-pull-turn, turn-push-turn-push, turn-pull-turn-pull), and paired series type (push-push-turn-turn, pull-pull-turn-turn, tunr-turn-push-push, turn-turn-pull-pull).
241 task-related neurons were recorded in the prefrontal cortex. Among them 77 neurons shdwed increased activity in first waiting period. 53 of 77 neurons were belonged to the one of three patterns; mono-series type 11; alternate series type 23; paired series type 19. Many neurons were recorded in and around the principal sulcus, especially in the upper part of principal snlcus. Such activities were not recorded in frontal eye field. These results indicate prefrontal cortex participate in categorization of sequential performance of multiple movements