Faster acquisition of an olfactory discrimination following septal lesions in male albino rats.

Normal rats and rats with septal lesions were maintained on a 23.5-hr water deprivation schedule and trained to bar press for water reinforcement, which was available during the presentation of one odor (SD) but not another (Sdelta). Vanilla and vinegar were the olfactants. Both groups showed evidence of discrimination within the first 2-hr of training and reached asymptotic discrimination ratios greater than 90 percent, but the rats with septal lesions reached successively higher levels of discrimination faster than the controls. The results suggest a septal inhibitory influence on the olfactory bulbs.