The amygdala, part of the brain reward circuitry, plays a role in cocaine-seeking and withdrawal in animals and craving and relapse in humans. The incentive motivation for cocaine is associated with cocaine cues and the amygdala is essential in forming drug-related associations. The membrane effects of chronic cocaine on amygdala neurons, however, are not known and mechanisms underlying drug-related associations are only beginning to be understood. The long-term objective of this research is to analyze the mechanisms underlying cocaine cue-related information by characterizing the modulation and modification of amygdala neurotransmission at the synaptic level during withdrawal from chronic cocaine. Chronic cocaine enhances glutamatergic transmission and group I metabotropic glutamate receptor (mGluR) effects in amygdala neurons. Dopamine also plays a role in cue related events in the amygdala. The proposed experiments will test the hypothesis that 2 weeks after withdrawal from chronic cocaine persistent alterations of neurotransmission and plasticity are specific for amygdala pathways and modulated by metabotropic glutamate and dopaminergic receptors. In these experiments synaptic transmission in intra-amygdala pathways is recorded using sharp electrode, whole cell patch, and extracellular recording in amygdala slices. The overall goal is to analyze membrane measures of cue-associated cocaine memory after chronic cocaine withdrawal, specifically: 1. Characterize the modifications in glutamatergic synaptic transmission and plasticity to stimuli representing drug-related cues and determine the underlying signaling mechanisms during chronic cocaine withdrawal; 2. Analyze the role of metabotropic glutamate and dopamine receptors in modulating synaptic transmission and plasticity and determine the underlying signaling mechanisms after withdrawal from chronic cocaine. These studies will determine synaptic mechanisms underlying neuroadaptations and intra-amygdala communication of drug-related cues after chronic cocaine withdrawal and may lead to novel and more rational strategies to block cue-induced relapse of cocaine addiction.

Agency
National Institute of Health (NIH)
Institute
National Institute on Drug Abuse (NIDA)
Type
Research Project (R01)
Project #
5R01DA017727-02
Application #
7082967
Study Section
Molecular Neuropharmacology and Signaling Study Section (MNPS)
Program Officer
Lin, Yu
Project Start
2005-07-01
Project End
2010-06-30
Budget Start
2006-07-01
Budget End
2007-06-30
Support Year
2
Fiscal Year
2006
Total Cost
$294,903
Indirect Cost
Name
University of Texas Medical Br Galveston
Department
Pharmacology
Type
Schools of Medicine
DUNS #
800771149
City
Galveston
State
TX
Country
United States
Zip Code
77555
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Schmidt, Kady; Krishnan, Balaji; Xia, Yan et al. (2011) Cocaine withdrawal reduces group I mGluR-mediated long-term potentiation via decreased GABAergic transmission in the amygdala. Eur J Neurosci 34:177-89
Krishnan, Balaji; Centeno, Marjorie; Pollandt, Sebastian et al. (2010) Dopamine receptor mechanisms mediate corticotropin-releasing factor-induced long-term potentiation in the rat amygdala following cocaine withdrawal. Eur J Neurosci 31:1027-42
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