Abstract
We examined whether the red nucleus (RN) lesion can modify cortically induced rhythmical jaw movements in rats anesthetized by urethane. Rhythmical jaw movements were induced by repetitive electrical stimulation of the orofacial motor cortex (OfM) and the insular cortex (IC). The RN lesions were made bilaterally by passing negative current. The distance between the maximum jaw-opening position and minimum jaw-opening positions was measured during rhythmical jaw movements. The duration of rhythmical jaw movements and the distance between the maximum jaw-opening position and minimum jaw-opening position before RN lesion was taken as 100%. The%age change in the duration of rhythmical jaw movements and the distance between the maximum jaw-opening position and minimum jaw-opening position after bilateral RN lesions were determined. The RN lesions did influence rhythmical jaw movements induced by stimulation of the OfM. The distance between the maximum jaw-opening position and minimum jaw-opening position 15 min and 30 min after lesions was significantly decreased to 60.7±15.8% and 56.1±15.9% (mean±S.E., n=10) of controls, respectively. The duration of rhythmical jaw movements 15 min and 30 min after lesions was significantly shortened to 60.4±12.6% and 42.8±12.4% of controls, respectively. On the other hand, lesions of the RN did not influence rhythmical jaw movements induced by stimulation of the IC. These results suggest that the RN is involved in the control of jaw movements induced by stimulation of the OfM. [J Physiol Sci. 2007;57 Suppl:S162]
