Chemogenetic disruption of the hippocampus impairs gustatory preconditioning in rats

Mélie M. Talaron, Nathan M. Holmes, Guillaume Ferreira, Etienne Coutureau
Neurobiology of Learning and Memory. 2026-07-01; 226: 108187
DOI: 10.1016/j.nlm.2026.108187

Talaron MM(1), Holmes NM(2), Ferreira G(3), Coutureau E(4).

Author information:
(1)Univ. Bordeaux, CNRS, INCIA, UMR 5287, Bordeaux F-33000, France; School of
Psychology, University of New South Wales, Sydney, New South Wales 2052,
Australia. Electronic address: .
(2)School of Psychology, University of New South Wales, Sydney, New South Wales
2052, Australia.
(3)Univ. Bordeaux, INRAE, Bordeaux INP, NutriNeuro, UMR 1286, Bordeaux F-33000,
France.
(4)Univ. Bordeaux, CNRS, INCIA, UMR 5287, Bordeaux F-33000, France.

Adaptive behavior often relies on learning associations between stimuli that
were never directly paired with reinforcement. Sensory preconditioning provides
a powerful paradigm to investigate such indirect learning: when neutral stimuli
A and X are paired during preconditioning, and X is subsequently paired with an
unconditioned stimulus (US) during conditioning, stimulus A elicits conditioned
response at test despite never being directly paired with the US. While the
hippocampus is known to be critical for this process, its involvement in
unimodal sensory preconditioning remains unclear. Here, we investigated the role
of the hippocampus (dorsal and ventral) during different phases of gustatory
preconditioning using chemogenetic approach in rats. We demonstrated that
disruption of the hippocampus during either preconditioning or test selectively
impaired the mediated aversion to A while leaving the direct conditioned
aversion to X intact. These findings provide the first evidence that the
hippocampus is necessary for unimodal gustatory preconditioning, extending
previous demonstrations of hippocampal involvement in polymodal protocols. Our
work therefore clarifies the critical role of the hippocampus in forming and
retrieving purely gustatory associations to guide behavior, highlighting its
function as a central hub for memory integration.

DOI: 10.1016/j.nlm.2026.108187
PMID: 42336191 [Indexed for MEDLINE]

Conflict of interest statement: Declaration of competing interest The authors
declare that they have no known competing financial interests or personal
relationships that could have appeared to influence the work reported in this
paper.