[Excitatory responses of superior salivatory nucleus neurons to stimulation of orbital gyrus in the cat].

The responses of superior salivatory nucleus (SSN) neurons to electrical stimulation of ipsilateral orbital gyrus were investigated in ketamine anesthetized cats. A total of 52 SSN neurons were identified by the antidromic spike responses to stimulation of the right chorda tympani nerve. Thirty-three (63%) neurons responded with spikes to stimulation of the orbital gyrus. These neurons were also activated by stimulation of ipsilateral lingual nerve. Eleven (21%) neurons received the inputs from only the lingual nerve. Remaining 8 (16%) neurons failed to respond to stimulation of neither orbital gyrus nor lingual nerve. The latency of orbital cortically evoked responses was 16.5-42.0 msec (mean +/- S.D. = 28.6 +/- 6.9 msec, n = 33), and that to stimulation of lingual nerve was 6.5-15.5 msec (9.9 +/- 2.4 msec, n = 46), respectively. In this study, convergence of excitatory inputs from orbital gyrus and sensory nerve was found in 63% of SSN neurons. These inputs would play an important role in submandibular and sublingual salivation.