A study of the area of distribution of the deep sensory neurons of the human ventral thalamus.

During neurosurgical treatment for the relief of movement disorders, thalamic neurons were identified with activity related to passive joint movement, active joint movement, deep sensory stimulation and superficial sensory stimulation. The cells responding to passive joint movement were located just rostral and dorsal to the cells responding to superficial sensory neurons. This area corresponded not only to Hassler's Vim (ventralis intermedius) nucleus but also to a part of the Vc (ventralis caudalis) nucleus. This distribution mode of cells responsive to passive joint movement was similar to that of the deep sensory neurons in the VPLo (ventralis posterior lateralis oralis) nucleus and in a portion (anterodorsal shell) of the VPLc (ventralis posterior lateralis caudalis) nucleus in the monkey thalamus. Recently, the anatomic and physiologic similarity between the human and monkey thalamic ventrolateral complex has been described. These results confirm the similarity between the human and monkey thalamic ventrolateral complex both anatomically and physiologically and could thus be useful for future studies exploring the neuronal mechanisms of involuntary movement disorders, such as tremor.