Both alpha(1)- and beta(1)-adrenoceptors in the bed nucleus of the stria terminalis are involved in the expression of conditioned contextual fear

Author(s)

Hott, Sara C. ^[1] ; Gomes, Felipe V. ^[1] ; Fabri, Denise R. S. ^[1] ; Reis, Daniel G. ^[1] ; Crestani, Carlos C. ^[2] ; Correa, Fernando M. A. ^[1] ; Resstel, Leonardo B. M. ^[1]

Affiliation

^[1] Univ Sao Paulo, Dept Pharmacol, Sch Med, BR-14049900 Ribeirao Preto, SP - Brazil

^[2] Sao Paulo State Univ, Dept Nat Act Principles & Toxicol, Sch Pharmaceut Sci, UNESP, Sao Paulo - Brazil

• Document type: Journal article
• Source: British Journal of Pharmacology; v. 167, n. 1, p. 207-221, SEP 2012.
• Web of Science Citations: 18

Abstract

BACKGROUND AND PURPOSE The bed nucleus of the stria terminalis (BNST) is a limbic structure that is involved in the expression of conditioned contextual fear. Among the numerous neural inputs to the BNST, noradrenergic synaptic terminals are prominent and some evidence suggests an activation of this noradrenergic neurotransmission in the BNST during aversive situations. Here, we have investigated the involvement of the BNST noradrenergic system in the modulation of behavioural and autonomic responses induced by conditioned contextual fear in rats. EXPERIMENTAL APPROACH Male Wistar rats with cannulae bilaterally implanted into the BNST were submitted to a 10 min conditioning session (6 footshocks, 1.5 ma/ 3 s). Twenty-four hours later freezing and autonomic responses (mean arterial pressure, heart rate and cutaneous temperature) to the conditioning box were measured for 10 min. The adrenoceptor antagonists were administered 10 min before the re-exposure to the aversive context. KEY RESULTS L-propranolol, a non-selective beta-adrenoceptor antagonist, and phentolamine, a non-selective a-adrenoceptor antagonist, reduced both freezing and autonomic responses induced by aversive context. Similar results were observed with CGP20712, a selective beta 1-adrenoceptor antagonist, and WB4101, a selective a1-antagonist, but not with ICI118,551, a selective beta 2-adrenoceptor antagonist or RX821002, a selective a2-antagonist. CONCLUSIONS AND IMPLICATIONS These findings support the idea that noradrenergic neurotransmission in the BNST via a1- and beta 1-adrenoceptors is involved in the expression of conditioned contextual fear. (AU)

• FAPESP's process: 11/13299-9 - Bed nucleus of the stria terminalis noradrenergic system modulates contextual fear conditionig: possible interaction with CRF and glutamatergic neurotransmission
• Grantee: Sara Cristina Hott
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 10/17343-0 - Evaluation of CBD effects on the molecular and behavioral changes induced by repeated treatment with MK-801
• Grantee: Felipe Villela Gomes
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 11/07332-3 - Possible role of dorsal hippocampus on behaviour and autonomic responses during defensive responses: involvement of NMDA receptor/nitric oxide and endocanabinoid
• Grantee: Leonardo Resstel Barbosa Moraes
• Support Opportunities: Regular Research Grants