Olfactory discrimination of fatty acids in rats with large bilateral lesions of the olfactory bulbs

Rats were trained to discriminate between varying concentrations of acetic acid and caproic acid and between acetic acid and propionic acid. Rats were tested on these tasks after receiving large bilateral bulbar lesions that included several of the fatty acid responsive areas identified in prior physiological studies. Experimental rats performed more poorly than unilateral bulb lesioned controls on the memory tests but had no significant deficits in discriminating fatty acids or in discriminating between the enantomiers of carvone. These results demonstrate that removal of most bulbar sites identified as responsive to fatty acids and the consequent disruption of patterned input to the bulb is largely without effect on discriminating odor qualities of similar acid vapors. The implications of these results for current concepts of odor coding are discussed.