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α2-adrenoceptor-mediated inhibition in the central amygdala blocks fear-conditioning


Holmes, NM and Crane, JW and Tang, M and Fam, J and Westbrook, RF and Delaney, A, α2-adrenoceptor-mediated inhibition in the central amygdala blocks fear-conditioning, Scientific reports, 7, (1) pp. 1-10. ISSN 2045-2322 (2018) [Refereed Article]


Copyright Statement

2017 The Authors. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0)

DOI: doi:10.1038/s41598-017-12115-x


The central amygdala is critical for the acquisition and expression of fear memories. This region receives a dense innervation from brainstem noradrenergic cell groups and has a high level of α2-adrenoceptor expression. Using whole-cell electrophysiological recordings from rat brain slices, we characterise the role of pre-synaptic α2-adrenoceptor in modulating discrete inhibitory and excitatory connections within both the lateral and medial division of the central amygdala. The selective α2-adrenoceptor agonist clonidine blocked the excitatory input from the pontine parabrachial neurons onto neurons of the lateral central amygdala. In addition, clonidine blocked inhibitory connections from the medial paracapsular intercalated cell mass onto both lateral and medial central amygdala neurons. To examine the behavioural consequence of α2-adrenoceptor-mediated inhibition of these inputs, we infused clonidine into the central amygdala prior to contextual fear-conditioning. In contrast to vehicle-infused rats, clonidine-infused animals displayed reduced levels of freezing 24 hours after training, despite showing no difference in freezing during the training session. These results reveal a role for α2-adrenoceptors within the central amygdala in the modulation of synaptic transmission and the formation of fear-memories. In addition, they provide further evidence for a role of the central amygdala in fear-memory formation.

Item Details

Item Type:Refereed Article
Research Division:Psychology
Research Group:Biological psychology
Research Field:Behavioural neuroscience
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in psychology
UTAS Author:Crane, JW (Dr James Crane)
ID Code:126379
Year Published:2018
Web of Science® Times Cited:7
Deposited By:Medicine
Deposited On:2018-06-07
Last Modified:2018-08-13
Downloads:66 View Download Statistics

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