NMDA-INDUCED RHYTHMICAL ACTIVITY IN XII-NERVE OF ISOLATED CNS FROM NEWBORN RATS

WE tried to induce rhythmical ore-facial motor activities in an isolat ed brain stem-spinal cord preparation from newborn rats. Neural activi ties were monitored from the hypoglossal nerve (XII N) and the ventral roots of the cervical cord. Bath application of N-methyl-D-aspartate (NMDA) as well as glutamate induced rhythmical burst activity in XII N distinct from and much faster than respiratory rhythm. This NMDA-indu ced rhythmical activity was blocked by simultaneous application of 2-a mino-5-phosphonovalerate (AP5). The results demonstrate that NMDA rece ptor activation can induce rhythmical XII N activity different from re spiration in an isolated mammalian CNS. This preparation will be usefu l for the investigation of neural mechanisms underlying the central ge neration of food ingestive movements.