The amygdala and fear memory

Elsevier eBooks, Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 1, 2024

Language: Английский

Dopamine D1-like receptors modulate synchronized oscillations in the hippocampal-prefrontal-amygdala circuit in contextual fear

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2023, Volume and Issue: unknown

Published: June 15, 2023

Abstract Contextual fear conditioning (CFC) is mediated by a neural circuit that includes the hippocampus, prefrontal cortex, and amygdala, but neurophysiological mechanisms underlying regulation of CFC neuromodulators remain unclear. Dopamine D1-like receptors (D1Rs) in this regulate local synaptic plasticity, which facilitated synchronized oscillations between these areas. In rats, we determined effects systemic D1R blockade on oscillatory synchrony dorsal hippocampus (DH), prelimbic (PL) basolateral amygdala (BLA), ventral (VH), sends hippocampal projections to PL BLA. altered DH-VH reduced VH-PL VH-BLA during CFC, as inferred from theta gamma coherence theta-gamma coupling. also impaired indicated decreased freezing at retrieval, was characterized VH-PL, VH-BLA, PL-BLA synchrony. This reduction VH-PL-BLA not fully accounted for non-specific locomotor effects, revealed comparing epochs movement controls. These results suggest D1Rs modulating within hippocampus-prefrontal-amygdala circuit. They add growing evidence indicating retrieval reflects signature learned fear.

Language: Английский

Closed-loop brain stimulation to reduce pathologic fear

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2022, Volume and Issue: unknown

Published: July 24, 2022

ABSTRACT Maladaptive processing of trauma related memory engrams leads to dysregulated fear reactions. In post-traumatic stress disorder (PTSD), dysfunctional extinction learning prevents discretization trauma-related and generalized responses. PTSD is postulated as a mnemonic-based disorder, but we lack markers or treatments targeting pathological processing. Hippocampal sharp wave-ripples (SWRs) concurrent neocortical oscillations are scaffolds consolidate contextual memory, their role during remains poorly understood. We demonstrate that closed-loop SWRs triggered neuromodulation the medial forebrain bundle (MFB) can enhance consolidation extinction. It modified memories became resistant induced recall (i.e., ‘renewal’ ‘reinstatement’) did not reemerge spontaneously PTSD-like phenotype. The effects mediated by D2 receptor signaling synaptic remodeling in basolateral amygdala. These results suggest help consolidating memories. Furthermore, enhancing SWR-triggered induction reward signals alleviate pathologic reactions rodent model PSTD. No adverse were seen, suggesting this potential therapy for anxiety disorders.

Language: Английский