Avoidance of GABA-containing diets by olfactory bulbectomized rats

In order to test the importance of olfaction in the avoidance of GABA-containing diets by intact rats, olfactory bulbectomized and sham-operated control rats were allowed to choose between a low protein control diet and this diet supplemented with 2.5% GABA; the specificity of the response was examined by also testing for responses to other amino acids. Both groups of rats markedly avoided the GABA diet initially; the bulbectomized rats later tended to increase their intake of this diet. The bulbectomized rats chose similar amounts from the control diet and one supplemented with alanine whereas the control rats ultimately strongly preferred the latter diet. Both groups only moderately avoided a threonine-supplemented diet. The results suggest that (1) the odor of GABA is not critical in the avoidance of diets containing this amino acid; and (2) patterns of food selection from diets containing GABA differ from choices from diets containing other small neutral amino acids such as alanine or threonine.