A study of motor control of the tongue : implications for swallowing

Abstract

ABSTRACT As the control of tongue movement is important during the first two phases of swallowing, the purpose of this study was to evaluate the initiation of swallowing by examining the control of tongue movement in a rat animal model. Measurement of the contractile properties of the tongue were made. The retrusive twitch and tetanic tensions evoked by stimulation of the whole Xllth nerve or lateral branch were significantly greater, than the protrusive responses elicited by medial branch stimulation. Maximum tetanic tension evoked by lateral branch stimulation was significantly greater than the maximum tetanic tension elicited by whole nerve stimulation. In addition, the protrusive contraction time of the tongue in response to medial branch stimulation was significantly faster than the retrusive contraction time in response to whole Xllth nerve or lateral branch stimulation. Also, the fatigue properties of the tongue muscles appear to be different than those of other rat muscles.