Abstract

• After unilateral lesion of the rat neostriatum, we have been studied the relation between the behavioral chages of the rat and structural chages of the substantia nigra. We could find that a great number of axon terminals with pleomorphic vesicles in the ipsilateral substantia nigra were degenerated after one site lesion of neostriatum. while the structure of contralateral site was entirely intact. Also, we have been investigated that the contralateral asymmetry of posture and turning bebavior of the rat with lesion in the neostriatum. By the above results, it can be concluded that the axon terminal with pleomorphic vesicles in the substantia nigra ending of strio-nigral fibers and the degeneration of these ending is a cause to bring the contralateral postural asymmetry and/or circle behavior.