title: Patterns of Theta Activity in Limbic Anxiety Circuit Preceding Exploratory Behavior in Approach-Avoidance Conflict.
abstract: Theta oscillations within the hippocampus-amygdala-medial prefrontal cortex (HPC-AMY-mPFC) circuit have been consistently implicated in the regulation of anxiety behaviors, including risk-assessment. To study if theta activity during risk-assessment was correlated with exploratory behavior in an approach/avoidance paradigm we recorded simultaneous local field potentials from this circuit in rats exploring the elevated-plus maze (EPM). Opposing patterns of power variations in the ventral hippocampus (vHPC), basolateral amygdala (BLA), and prelimbic (PrL) mPFC, but not in the dorsal hippocampus (dHPC), during exploratory risk-assessment of the open arms preceded further exploration of the open arms or retreat back to the safer closed arms. The same patterns of theta power variations in the HPC-BLA-mPFC(PrL) circuit were also displayed by animals submitted to chronic unpredictable stress protocol known to induce an anxious state. Diverging patterns of vHPC-mPFC(PrL) theta coherence were also significantly correlated with forthcoming approach or avoidance behavior in the conflict situation in both controls and stressed animals; interestingly, vHPC-BLA, and BLA-mPFC(PrL) theta coherence correlated with future behavior only in stressed animals, underlying the pivotal role of the amygdala on the stress response.
authors.affiliation: Life and Health Sciences Research Institute, University of MinhoBraga, Portugal; ICVS/3B's - PT Government Associate LaboratoryBraga/Guimarães, Portugal.
authors.forename: Luis R
authors.initials: LR
authors.lastname: Jacinto
authors.affiliation: Life and Health Sciences Research Institute, University of MinhoBraga, Portugal; ICVS/3B's - PT Government Associate LaboratoryBraga/Guimarães, Portugal.
authors.forename: João J
authors.initials: JJ
authors.lastname: Cerqueira
authors.affiliation: Life and Health Sciences Research Institute, University of MinhoBraga, Portugal; ICVS/3B's - PT Government Associate LaboratoryBraga/Guimarães, Portugal.
authors.forename: Nuno
authors.initials: N
authors.lastname: Sousa
keywords: amygdala; anxiety; local field potentials; prefrontal cortex; stress; ventral hippocampus