Motor effects of stimulation and ablation of the caudate nucleus of the monkey

Electric stimulation of the caudate nucleus of the lightly anesthetized monkey was undertaken to demonstrate contralateral extremity movement. Contralateral forelimb flexion was observed in 75 percent of stimulations. The caudate nuclei were subsequently ablated, and 40 percent showed abnormal movements, mainly ipsilateral torticollis and ipsilateral eye deviation. The findings are consistent with previous studies using the caudate nucleus of the cat.