The basolateral amygdala is necessary for the encoding and the expression of odor memory.
Learning & Memory. 2009-03-20; 16(4): 235-242
Read on PubMed
1. Learn Mem. 2009 Mar 20;16(4):235-42. doi: 10.1101/lm.1247609. Print 2009 Apr.
The basolateral amygdala is necessary for the encoding and the expression of odor
Sevelinges Y(1), Desgranges B, Ferreira G.
(1)Laboratoire de Comportement, Neurobiologie et Adaptation, CNRS UMR 6175, INRA
UMR 85, Université Tours, Nouzilly, France.
Conditioned odor avoidance (COA) results from the association between a novel
odor and a delayed visceral illness. The present experiments investigated the
role of the basolateral amygdala (BLA) in acquisition and retrieval of COA
memory. To address this, we used the GABA(A) agonist muscimol to temporarily
inactivate the BLA during COA acquisition or expression. BLA inactivation before
odor-malaise pairing greatly impaired COA tested 3 d later. In contrast, muscimol
microinfusion between odor and malaise spared retention. Moreover, inactivation
of the BLA before pre-exposure to the odor prevented latent inhibition of COA.
This suggests that neural activity in the BLA is essential for the formation of
odor representation. BLA inactivation before the retrieval test also blocked COA
memory expression when performed either 3 d (recent memory) or 28 d (remote
memory) after acquisition. This effect was transitory as muscimol-treated animals
were not different from controls during the subsequent extinction tests.
Moreover, muscimol infusion in the BLA neither affected olfactory perception nor
avoidance behavior, and it did not induce a state-dependent learning. Altogether,
these findings suggest that neural activity in the BLA is required for the
encoding and the retrieval of odor memory. Moreover, the BLA seems to play a
permanent role in the expression of COA.
PMID: 19304894 [Indexed for MEDLINE]