Movements Evoked from the Region of the Caudate Nucleus in Gats

Abstract

Abstract M osfeldt L aursen , A. Movements evoked from the region of the caudate nucleus in cats. Acta physiol. scand. 1962. 54. 175–184. – The caudate nucleus and adjacent structures were stimulated in alert cats with implanted electrodes. With a 14 lead multielectrode assembly thresholds could be determined successively in points known distances apart without intervening displacement of brain tissue. Contraversive head turning and circling were the only motor responses of caudate origin: they were eliminated by lesions in the caudate whereas degeneration of the internal capsule left them unaffected. Flexion of contralateral extremities previously attributed to the caudate was elicited with the lowest threshold when stimuli were applied to the internal capsule. It remained unaffected by lesions in the caudate whereas it was eliminated by degeneration of the internal capsule. Thus when flexion of contralateral extremities was obtained from lead pairs of the multilead electrode situated in the caudate the response must be assumed to be due to stimulation of the internal capsule by current spread. It is consistent with this interpretation that contraversive head turning‐circling and contralateral flexion had their lowest thresholds at different frequencies of stimulation. Lip‐smacking, salivation and other responses with vegetative components were elicited from lead pairs of the multilead electrode in the septum or by current spread from electrodes in the caudate to the septum. The results were confirmed using bipolar electrodes of conventional design.