Hippocampal dendritic spines remodeling and fear memory are modulated by GABAergic signaling within the basolateral amygdala complex.

GIACHERO M, ; CALFA, G. ; MOLINA VICTOR ALEJANDRO

HIPPOCAMPUS

WILEY-LISS, DIV JOHN WILEY & SONS INC

Lugar: New York; Año: 2015 vol. 25 p. 545 - 555

1050-9631

GABAergic signaling in the basolateral amygdala complex(BLA) plays a crucial role on the modulation of the stress influenceon fear memory. Moreover, accumulating evidence suggests that thedorsal hippocampus (DH) is a downstream target of BLA neurons incontextual fear. Given that hippocampal structural plasticity is proposedto provide a substrate for the storage of long-term memories, the mainaim of this study is to evaluate the modulation of GABA neurotransmissionin the BLA on spine density in the DH following stress on contextualfear learning. The present findings show that prior stressfulexperience promoted contextual fear memory and enhanced spine densityin the DH. Intra-BLA infusion of midazolam, a positive modulatorof GABAa sites, prevented the facilitating influence of stress on bothfear retention and hippocampal dendritic spine remodeling. Similarly tothe stress-induced effects, the blockade of GABAa sites within the BLAameliorated fear memory emergence and induced structural remodelingin the DH. These findings suggest that GABAergic transmission in BLAmodulates the structural changes in DH associated to the influence ofstress on fear memory.