Short latency somaesthetic responses in motor cortex, transmitted through the spino-thalamic system, in the cat.

Evidence is presented that in the cat, the spinothalamic system contributes to short latency somaesthetic responses in motor cortex efferent cells. Intracellular recordings performed on identified pyramidal tract cells and corticospinal cells show that these cells are still activated and/or inhibited from the periphery after a set of central nervous lesions leaving intact only the ventral half of the spinal cord. The responses were attributed to the spinothalamic system. The ascending system is activated through collaterals of afferent fibres running in the dorsal columns of the spinal cord. This peripheral link to the motor cortex might participate in updating the motor command on the basis of information feedback from the periphery.