Discrimination of social odors and their locations: role of lateral entorhinal area.
Discrimination of individual conspecifics by their odors has been reported for many mammalian species, but little information is available on the brain mechanisms underlying such discrimination. A previous study reported that large parahippocampal lesions, centered on entorhinal cortex but extending into adjacent areas of the brain, eliminated female hamsters' ability to discriminate the flank gland odors of different individuals, as tested with habituation-dishabituation methods. The current study examined the effects of lesions restricted to the lateral entorhinal area on such discriminations. Female hamsters were tested in several types of habituation procedure that differed across a sequence of trials in the locations of familiar and novel social odors. Discrimination of two individuals' odors depended on the sequences of locations of the odors, indicating that odor identity and location were simultaneously salient to female hamsters. Lesions of lateral entorhinal area interfered with this spatial-olfactory discrimination. When confounding spatial cues were eliminated, hamsters did discriminate between novel and familiar odors, and lesions in the entorhinal area did not eliminate this ability. Thus, although the lateral entorhinal area is not necessary for individual odor discrimination, it is involved in processing odor-place combinations.
Department of Psychology, Cornell University, Uris Hall, Ithaca, NY 14853, USA. dmayeaux@sbu.edu
Darryl J
DJ
Mayeaux
Robert E
RE
Johnston
D000818:Animals; D006224:Cricetinae; D004192:Discrimination, Psychological / Q000502:physiology*; D018728:Entorhinal Cortex / Q000033:anatomy & histology / Q000502:physiology*; D030762:Estrous Cycle / Q000502:physiology; D005260:Female; D008647:Mesocricetus; D009812:Odorants; D010812:Physical Stimulation; D011187:Posture; D012726:Sexual Behavior, Animal / Q000502:physiology; D012903:Smell / Q000502:physiology*; D012931:Social Environment; D013238:Stereotaxic Techniques