Effects of opioid and GABAergic modulation of the dPAG neurons on the conditioned fear of rats tested under alcohol withdrawal, submitted to chronic stress, and previously selected for their low or high anxiety levels

• Grant number: 10/06165-3
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): June 01, 2010
• Effective date (End): December 31, 2010
• Field of knowledge: Humanities - Psychology
• Principal Investigator: Manoel Jorge Nobre Do Espirito Santo
• Grantee: Laís Batista Carmo Silva
• Home Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Alcohol reinforcing effects result from its interaction with various systems of neurotransmitter in the brain, such as the GABAergic and opioid ones, among others, which makes its pharmacodynamic action more complex than that of other drugs of abuse, producing selective and dose-dependent effects. Withdrawal from drugs of abuse have a feature of an unconditioned stressor and as such, may be under the control of neuronal systems and brain regions that often modulate the body's response to unconditioned fear stimuli, among them the dorsal periaqueductal gray (dPAG). This region, together with the superior and inferior colliculi and raphe nuclei, is involved in the integration of defensive reaction to aversive stimuli that naturally produce fear. Particularly with regard to dPAG, it has been shown that alcohol withdrawal induces a pronounced increase in sensitivity to electrical stimulation of its neurons, suggesting that the increased levels of anxiety present during withdrawal may be associated with the sensitization of the neuronal substrates of unconditioned fear and anxiety in these regions. This type of response keeps a great resemblance to many of the symptoms observed in abstinent individuals. This experiment aims to study the influence of chronic stress exposure on the conditioned fear response of alcohol withdrawn-rats, previously selected for their high or low emotional reactivity (high or low anxious), and the importance of the opioid and GABA receptors of dPAG neurons on the modulation of this response.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

CARMO SILVA, LAIS BATISTA; NOBRE, MANOEL JORGE. Impaired fear inhibitory properties of GABA(A) and mu opioid receptors of the dorsal periaqueductal grey in alcohol-withdrawn rats. ACTA NEUROBIOLOGIAE EXPERIMENTALIS, v. 74, n. 1, p. 54-66, 2014. Web of Science Citations: 5.