Olfactory discrimination in rats with anterior amygdala lesions.

In Experiment 1, rats with posterior lateral olfactory tract/anterior amygdala lesions or with control neocortical lesions were tested for retention of a preoperatively learned odor detection task and for learning on new odor discrimination problems. All rats had perfect or near-perfect retention of the detection task, and there were no discernible differences between groups in learning on the new odor discrimination problems. In Experiment 2, an intensity-difference threshold for olfaction was determined in 4 rats before and after lesions of the posterior lateral olfactory tract and anterior amygdala. There were no apparent differences between pre- and postoperative performances on this psychophysical test. These results indicate that lateral olfactory tract projections to the amygdala and posterior olfactory cortex are not essential for normal performance on simple olfactory discrimination tasks.