Abstract
The motor effects induced by intracortical microstimulation (ICMS), suggested that there are three orofacial motor and masticatory cortical areas in cats; the ventral bank of the cruciate sulcus (area M), the anterior part of the coronal gyrus (area C), the lateral wall of the presylvian sulcus (area P), and the masticatory cortical area (area MA). In the present study, to investigate the function of these four areas and the first somatosensory cortex (SI), single neuronal activities were recorded in each cortical area during mastication in 20 conscious cats. Many MRNs in areas C, P, M, MA and SI received inputs from the tongue and the perioral regions. Furthermore, the relationship between the activity pat tern of MRNs and orofaical behavior during mastication was examined. MRNs in M and in P may control the tension of the perioral region and tongue movements. Sensory inputs evoked by masticatory movements were subdivided into perioral and tongue inputs in the SI. The sensory information is integrated in the MA and C. Integrated information will transport toward the M and the P.
These findings suggest that mastication is activated by the cooperation among various area (M, P, C, MA and SI).
