PSYC 427 Lecture Notes - Lecture 12: Thenar Eminence, Supplementary Motor Area, Frontal Lobe
Document Summary
Single cells in monkey motor cortex are activated at short latency by deep (proprioceptive) and cutaneous stimuli. Short latency sensory input reaches m1 from somatosensory cortex and possibly directly from the thalamus. M1 surface potential evoked by stimulating peripheral nerves when sensory cortex was ablated. If you eliminate somatosensory cortex then there must"ve been another pathway to motor cortex (direct via thalamus). But this is not really the case there are inputs that come up dorsal column cuneate thalamus, but when combining anterograde and retrograde labeling ends up on different neurons in thalamus than those that project directly to m1. M1 does get direct input, but it"s not proprioceptive (spinal cord thalamus motor cortex) The signals seem to pass via somatosensory cortex in the cortical motor areas. M1 input may be restricted to spinothalamic inputs (thermal, nociception, coarse- touch) Like neurons in somatosensory cortex, neurons in motor cortex have sensory receptive fields.
