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Loss of δ‐GABA A receptor‐mediated tonic currents in the adult prelimbic cortex following adolescent alcohol exposure
Author(s) -
Centanni Samuel W.,
Burnett Elizabeth J.,
TranthamDavidson Heather,
Chandler L. Judson
Publication year - 2017
Publication title -
addiction biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.445
H-Index - 78
eISSN - 1369-1600
pISSN - 1355-6215
DOI - 10.1111/adb.12353
Subject(s) - tonic (physiology) , gabaa receptor , infralimbic cortex , prefrontal cortex , endocrinology , medicine , neuroscience , chemistry , receptor , agonist , neurotransmission , biology , cognition
Delayed maturation of the adolescent prefrontal cortex may render it particularly vulnerable to insults, including those associated with drugs of abuse. Using a rat model of binge alcohol exposure, the present study examined the effect of adolescent intermittent ethanol (AIE) exposure during postnatal days 28–42 on γ‐aminobutyric acid (GABA)ergic neurotransmission in the prelimbic cortex. In control rats, patch‐clamp electrophysiology in acute slices obtained at different postnatal ages revealed a developmental increase in the GABA A receptor‐mediated tonic current in layer V pyramidal neurons but no change in layers II/III when measured in the adult. In slices from AIE‐exposed rats, the amplitude of the tonic current was significantly reduced compared with controls when tested at postnatal days 45, 60 and 90–120. This AIE‐induced reduction in tonic current was found to reflect attenuation of currents mediated by δ‐subunit containing receptors. Consistent with this, facilitation of the tonic current by bath application of either ethanol or allopregnanolone was attenuated in slices from AIE‐exposed adult rats compared with control rats. However, expression of this facilitation as a percent of the amplitude of the total current mediated by δ‐GABA A receptors revealed that AIE did not alter their sensitivity to either agonist. Lastly, immunohistochemistry and Western blot analysis revealed no change in the expression of δ‐GABA A subunits or their surface expression. Taken together, these studies reveal that AIE exposure results in persistent deficits in δ‐GABA A tonic currents in the adult prelimbic cortex that may contribute to deficits in decision‐making and behavioral control in adulthood.