Reflex responses of single salivatory neurons to stimulation of trigeminal sensory branches in the cat.

Responses of 71 single salivatory neurons, identified by antidromic spikes evoked by stimulation of the chorda tympani, were tested to stimulation of the ipsilateral infraorbital (IO), inferior alveolar (IA) and lingual nerves (LN) in the cat. Fifty-one neurons responded with spike potentials to stimulation of one or more of these nerves (responsive type, R), while the remaining 20 neurons did not respond to stimulation of any of them (non-responsive type, NR). Thirty-three R neurons were activated by stimulation of all of the 3 trigeminal afferent branches, while 12 neurons responded with spikes to stimulation of only one branch, usually of LN. Reflex spike responses appeared with a latency of 5.6-14.6 ms to LN stimulation, 6.4-15.7 ms to IO stimulation and 6.0-26.0 ms to IA stimulation. Impulses of both A beta and A delta afferent fibres of the trigeminal nerve were found to be effective for activation of salivatory neurons.