ABSTRACT
The gustatory system regulates the perception, transduction, and transmission of the gustatory impulses. It recognizes the concentration and the pleasurable or harmful qualities of the consumed substances. It responds to a diverse type of taste sensations. Taste, as a chemical sensation, shares common connections and characteristics with the olfactory system, entailing the stimulation of the gustatory modied epithelial receptors, primarily G protein coupled and, to lesser degree, ion channel receptors. The taste receptors are scattered on the distinct papillae of the dorsum of the tongue, epiglottic vallecula, and soft palate. Transduction of the chemical stimuli by the gustatory receptors is eventually transmitted via bers of the facial, glossopharyngeal, and vagus nerves, which link with the neurons of the solitary nucleus and, ultimately, with the gustatory cortex through the ventromedial thalamic nucleus. A parallel link enables the gustatory impulses to travel to the hypothalamus and amygdala to regulate autonomic activities induced by taste. The quality of taste is determined by activation of several clusters of well-dened central and peripheral gustatory neurons. Due to the multisynaptic connection of the gustatory pathway, continuous replacement of the taste receptors and the reexive taste-elicited behavior are factors that enable this system to resist potential injuries.
