The entorhinal cortex is involved in conditioned odor and context aversions.
In a natural environment, avoidance of a particular food source is mostly determined by a previous intake experience during which sensory stimuli such as food odor, become aversive through a simple associative conditioned learning. Conditioned odor aversion learning (COA) is a food conditioning paradigm that results from the association between a tasteless scented solution (conditioned stimulus, CS) and a gastric malaise (unconditioned stimulus, US) that followed its ingestion. In the present experimental conditions, acquisition of COA also led to acquisition of aversion toward the context in which the CS was presented (conditioned context aversion, CCA). Previous data have shown that the entorhinal cortex (EC) is involved in the memory processes underlying COA acquisition and context fear conditioning, but whether EC lesion modulates CCA acquisition has never be investigated. To this aim, male Long-Evans rats with bilateral EC lesion received CS-US pairings in a particular context with different interstimulus intervals (ISI). The results showed that the establishment of COA with long ISI obtained in EC-lesioned rats is associated with altered CCA learning. Since ISI has been suggested to be the determining factor in the odor- and context-US association, our results show that the EC is involved in the processes that control both associations relative to ISI duration.
Centre of Research in Neuroscience, CNRS UMR 5292 - INSERM U1028 - UCBL1 Lyon, France.
Barbara
B
Ferry
Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, Faculté de Psychologie, CNRS, Université de Strasbourg, Neuropôle de Strasbourg, GDR 2905 du CNRS Strasbourg, France.
Karine
K
Herbeaux
Etablissement Public de Santé Alsace Nord Brumath - Service Pharmacie - CHU de Strasbourg, Hôpital Civil, Clinique de Psychiatrie - Service de Psychiatrie II Brumath, France.
Hervé
H
Javelot
Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, Faculté de Psychologie, CNRS, Université de Strasbourg, Neuropôle de Strasbourg, GDR 2905 du CNRS Strasbourg, France.
Monique
M
Majchrzak
context aversion; entorhinal cortex; food conditioning; odor aversion; odors