Friday, April 30, 2010

Decreased beta2*-nicotinic acetylcholine receptor availability after chronic ethanol exposure in nonhuman primates



Ethanol associated behaviors have been linked to the 2-subunit containing nicotinic acetylcholine receptors (2*-nAChR); however, there is conflicting evidence on ethanol-induced changes in nAChR expression during and after chronic ethanol consumption.

In this study, five male animals orally self-administered ethanol for 18 ± 1 weeks. Animals were scanned with [
123I]5-IA-85380 and SPECT prior to ethanol self-administration, and at 24 h and 5-13 wks withdrawal.

2 *-nAChR availability was not significantly different from baseline at 24 h withdrawal, but was significantly decreased compared to baseline at 5-13 wks withdrawal throughout the cortex and in the thalamus, but not the midbrain.

The percent decrease in
2*-nAChR availability from baseline to 5-13 wks withdrawal in the parietal cortex was negatively correlated with total grams of ethanol consumed in lifetime and in the midbrain was negatively correlated with average daily ethanol consumption (g/kg).

Prolonged withdrawal from chronic ethanol consumption is associated with a decrease in
2*-nAChR availability.

The decrease in
2*-nAChR availability is influenced by alcohol consumption, suggesting the chronicity and severity of alcohol consumption may underlie persistent changes in 2*-nAChR availability.

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Request Reprint E-Mail: kelly.cosgrove@yale.edu


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