Taste relay neurons in the solitary tract nucleus of rats.

Impulse discharges of 82 solitary tract nucleus neurons, in response to natural stimulation of the oral cavity, were recorded. Among these, 52 units responded to taste stimuli and 30 units to mechanical stimuli. When the caudal end of the parabrachial nucleus was stimulated ipsilaterally, 16 taste and 5 mechanoreceptive units were excited antidromically. Response types of rostrally projecting taste neurons were not different from those of the non-projecting ones, and both of them were similar to that of the chorda tympani.