FUNCTIONAL RELATION OF INTERSTITIAL NUCLEUS TO ROTATORY MOVEMENTS EVOKED FROM ZONA INCERTA STIMULATION

Abstract

[image]The effect of acute lesions in and near the interstitial nucleus of Cajal (NIC) was determined in cats prepared as encephale isoles. Ocular torsion evoked by stimulation of zona incerta was significantly depressed or abolished after destruction in or medial to the ipsilateral NIC, but not in surrounding areas. The effect of chronic lesions in or near NIC was assessed on head and eye rotation. Head rotation evoked by stimulation through chronically implanted electrodes was significantly depressed in 3 cats following placement of a lesion just postero-medial to the NIC. Ocular rotation, in response to head tilt or to stimulation of zona incerta in encephale isole preparations, was seen after each of these lesions. Thus the integrity of the NIC would appear to be essential for mediation of rotatory movements evoked from stimulation in the ipsilateral zona incerta. However, the same elements of the NIC do not appear to mediate all rotations of the head and of the eyes.