Changes on auditory physiology in response to the inactivation of amygdala nuclei in high anxiety rats expressing learned fear

Autor(es)

Nobre, Manoel Jorge ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Psicol, Fac Filosofia Ciencias & Letras Ribeirao Preto, BR-14090901 Ribeirao Preto, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Physiology & Behavior; v. 118, p. 80-87, JUN 13 2013.
• Citações Web of Science: 4

Resumo

The inferior colliculus (IC) is primarily involved in the processing of acoustic stimuli, including those emitted by prey and predators. The role of the central nucleus of the IC (CIC) in fear and anxiety has been suggested based on electrophysiological, behavioral and immunohistochemical studies. The reactivity of high-anxiety rats (HA) to diverse challenges is different from low-anxiety ones (LA). In humans and laboratory animals, pathological anxiety is often accompanied by heightened vigilance and alertness, hyperactivity of the amygdala (AM), and increased amplitude of the auditory evoked potentials (AEP) from the IC. This study aims to evaluate the influence of the inactivation of the central (CEA) and basolateral (BLA) nuclei of the amygdala, after local infusions of the full GABA(A) agonist muscimol (1 nmol/0.2 mu l), on the AEP elicited in the CIC of rats tested under a learned fear state. Our results showed that both BLA and CEA inactivation change the expression of conditioned fear, in a paradigm using the context as the conditioned stimulus (CS). These changes are correlated to the innate anxiety levels of the animals. It is supposed that this shortcoming is in addition to the imbalance between the regulatory role of the top-down and bottom-up processes in the control of anxiety. (C) 2013 Elsevier Inc. All rights reserved. (AU)

• Processo FAPESP: 08/05724-9 - NEUROBIOLOGIA DO ABUSO DE DROGAS: Estudo comportamental e farmacológico sobre o medo e ansiedade eliciados em ratos abstinentes de álcool e morfina, e da importância de estruturas mesencefálicas na modulação dessas respostas.
• Beneficiário: Manoel Jorge Nobre Do Espirito Santo
• Modalidade de apoio: Auxílio à Pesquisa - Regular