Area postrema lesions cause overconsumption of palatable foods but not calories.

Rats with lesions of the area postrema and immediately adjacent solitary nucleus consume greater amounts of highly palatable food during short exposures than do control rats. When a highly palatable substance (cookies or glucose solutions) is available continuously along with laboratory chow, lesioned rats exhibit average 24 hour calorie intakes which are not different from those of control rats. Nevertheless, the lesioned animals ingest a significantly greater proportion of total calories as the highly palatable substances than do control rats. The data suggest that lesions involving the area postrema and adjacent nucleus of the solitary tract enhance intake of highly palatable food without causing overconsumption of calories.