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Orbitofrontal and insular cortex: Neural responses to cocaine‐associated cues and cocaine self‐administration
Author(s) -
Guillem Karine,
Kravitz Alexxai V.,
Moorman David E.,
Peoples Laura L.
Publication year - 2010
Publication title -
synapse
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.809
H-Index - 106
eISSN - 1098-2396
pISSN - 0887-4476
DOI - 10.1002/syn.20698
Subject(s) - orbitofrontal cortex , psychology , self administration , neuroscience , reinforcement , stimulus (psychology) , electrophysiology , prefrontal cortex , population , anesthesia , medicine , cognition , cognitive psychology , social psychology , environmental health
Based on neuro‐imaging studies in cocaine‐addicted humans, it is hypothesized that increases in neural activity within several regions of the prefrontal cortex contribute to cue‐induced cocaine seeking and cocaine‐induced compulsive drug self‐administration. However, electrophysiological tests of these hypotheses are lacking. In the present study, animals were trained to self‐administer cocaine (0.75 mg/kg) for 14 days. On the 14th day, we conducted electrophysiological recordings of lateral orbitofrontal (LO) and ventral anterior insula (AIV) neurons. A subset of the combined population of recorded neurons showed a change in firing rate in association with one or more of the following discrete events: (1) presentation of a discriminative stimulus that signaled the onset of the self‐administration session, (2) occurrence of the first cocaine‐directed operant response, (3) occurrence of a cocaine‐reinforced press, and (4) presentation of cues normally paired with delivery of the cocaine reinforcer. The majority of the stimulus‐ and response‐related changes in firing involved a brief increase in firing during the stimulus and response event, respectively. In addition to these event‐specific responses, approximately half of the recorded neurons exhibited a sustained change in average firing (i.e., discharges per 30‐s bin) during the cocaine self‐administration session, relative to average firing during a presession, drug‐free period (referred to as session changes). The prevalence of session‐increases and decreases were not significantly different. These and other findings are discussed in relation to hypotheses about cue‐evoked and cocaine‐maintained cocaine‐directed behavior. Synapse 64:1–13, 2010. © 2009 Wiley‐Liss, Inc.