Neural descending pathways from the cortical jaw motor area and amygdaloid nucleus to jaw muscles.

Previously1), we have determined the various jaw movements of rabbits that can be evoked by electrical stimulation of the cortical jaw motor region. Jaw movement induced by stimulation of the neocortical jaw motor region was predominant in a jaw opening direction whereas that following stimulation of the amygdala was predominant in a jaw closing direction. Additionally, these two brain regions could induce jaw movements independently. In this experiment, the representation in these brain structures of each jaw muscle and the descending neural pathways from the neocortex and amygdaloid nucleus concerned with jaw movement were explored physiologically .