Neuronal dynamics supporting formation and recombination of cross-modal olfactory-tactile association in the rat hippocampal formation.

The present study is aimed at describing some aspects of the neural dynamics supporting discrimination of olfactory-tactile paired-associated stimuli during acquisition of new pairs and during recombination of previously learned pairs in the rat. To solve the task, animals have to identify one odor-texture (OT) combination associated with a food reward among three cups with overlapping elements. Previous experiments demonstrated that the lateral entorhinal cortex (LEC) is involved in the processes underlying OT acquisition, whereas the dorsal hippocampus (DH) is selectively involved in the recombination processes.

Involvement of the lateral entorhinal cortex for the formation of cross-modal olfactory-tactile associations in the rat.

While the olfactory and tactile vibrissal systems have been extensively studied in the rat, the neural basis of these cross-modal associations is still elusive. Here we tested the hypothesis that the lateral entorhinal cortex (LEC) could be particularly involved. In order to tackle this question, we have developed a new behavioral paradigm which consists in finding one baited cup (+) among three, each of the cups presenting a different and specific odor/texture (OT) combination.