ABSTRACT
The nucleus tractus solitarius (NTS), the first central relay for taste input, contains neurons that drive the decision to swallow or reject a potential food. The NTS receives information regarding stimulus attributes through afferent activity in taste nerves, and signals about nutritive state and postingestional consequences through visceral afferents. There are cogent arguments for four or five independent classes of taste stimuli that may be established at the receptor level, maintained throughout the processing chain, and experienced as qualitatively distinct perceptions. NTS neurons were categorized into several groups based on their response profiles to the entire stimulus array before amiloride. Since the responses to chemicals that do not contain sodium or lithium ions remain unaffected in the NTS, these stimuli must not be transduced by receptors that have amiloride-sensitive channels. The majority of the caudal half of the NTS receives input from the gastrointestinal tract.
