The role of the gustatory thalamus in taste-guided behavior.

Gustatory thalamus is the functional name for the parvicellular region of the ventroposteromedial nucleus of the thalamus. It is the penultimate nucleus in the thalamocortical pathway of the central gustatory system. Early research encouraged the view that the gustatory thalamus was important for taste detection and recognition. Consistent with this analysis, lesions of the area were found to induce profound deficits of innate taste preferences and aversions, salt appetite, and conditioned taste aversions (CTAs). More recent research using discrete lesions placed with electrophysiological guidance has, however, demonstrated that these deficits were due to damage to structures outside of, rather than within, the boundaries of the gustatory thalamus. In fact, the new data show that the gustatory thalamus is not essential for taste detection, sodium appetite, or CTA learning, but is critical for the preparatory (i.e. food-seeking) rather than the consummatory (i.e. food-eating) aspects of taste-guided behavior.