Aversive sensation in the brain after eating unpalatable food

Taste plays an important role in the regulation of food and fluid intake in animals. Taste information on the tongue is transmitted to the brain, and we feel hedonic or aversive sensation from the taste of a food. Various studies have shown that opioids or the dopamigenic system is deeply related to the hedonic response in the brain. Few studies have been made, however, about the aversion to food, which is an important signal for animals to protect them from poison that usually has a bitter taste and causes an aversive sensation. We recently suggested that diazepam binding inhibitor (DBI) was released in the brain after stimulation by an aversive taste and might be involved in the aversive sensations of taste. In this review we describe the studies on aversive sensation after eating and propose a novel concept that food aversion may be divided into aversion and rejection. Furthermore, we suggest that DBI is involved in aversion.