Projection to parabrachial nucleus of solitary tract nucleus neurons activated by tongue afferents in rats.

Eighty-eight solitary tract nucleus neurons of anesthetized rats were recorded extracellularly, and investigated by the spike responses to stimulation of the three tongue afferents and the ipsilateral parabrachial nucleus. Among them, 21 neurons were found to receive antidromic invasions from the parabrachial nucleus. Moreover, they were mostly excited by stimulation of the nerves innervating the anterior tongue.