[Taste].

Taste has a dual role. Like other senses it informs the individual about the external world, but unlike other senses it connects that perception with information about the internal environment. The principal function of taste is similar in all higher species. Molecules act on specialized sensory cells (= taste cells) in various regions of the oral cavity thus triggering signals, which are relayed to the cortex via afferent nerves, the caudal hindbrain and the thalamus. Taste afferents also reach the hypothalamus and the limbic system. The taste of food triggers physiological and behavioral reactions in man and animals. Stimulation of taste cells immediately elicits salivation, secretion of gastric acid and pancreatic juice as well as secretion of gastrointestinal and pancreatic hormones. Innate and learned taste preferences or aversions play an important role in food selection and taste aversions are considered to be reliable indicators of malaise. Neural signals from the periphery or humoral factors which are sensed by receptors in the central nervous system both can change the acceptance of a certain taste. Endogenous opiates in the brain seem to play a special role in the modulation of taste perception. The amygdala is apparently a brain area which is particularly important for taste perception.