University of Massachusetts Medical School Faculty Publications

Title

Nicotinic acetylcholine receptors containing the alpha4 subunit modulate alcohol reward

UMMS Affiliation

Department of Psychiatry, Brudnick Neuropsychiatric Research Institute

Publication Date

4-15-2013

Document Type

Article

Subjects

Receptors, Nicotinic; Dopaminergic Neurons; Ethanol; Alcoholism

Disciplines

Mental Disorders | Molecular and Cellular Neuroscience | Neuroscience and Neurobiology | Substance Abuse and Addiction

Abstract

BACKGROUND: Nicotine and alcohol are the two most co-abused drugs in the world, suggesting a common mechanism of action might underlie their rewarding properties. Although nicotine elicits reward by activating ventral tegmental area dopaminergic (DAergic) neurons via high-affinity neuronal nicotinic acetylcholine receptors (nAChRs), the mechanism by which alcohol activates these neurons is unclear.

METHODS: Because most high-affinity nAChRs expressed in ventral tegmental area DAergic neurons contain the alpha4 subunit, we measured ethanol-induced activation of DAergic neurons in midbrain slices from two complementary mouse models, an alpha4 knock-out (KO) mouse line and a knock-in line (Leu9'Ala) expressing alpha4 subunit-containing nAChRs hypersensitive to agonist compared with wild-type (WT). Activation of DAergic neurons by ethanol was analyzed with both biophysical and immunohistochemical approaches in midbrain slices. The ability of alcohol to condition a place preference in each mouse model was also measured.

RESULTS: At intoxicating concentrations, ethanol activation of DAergic neurons was significantly reduced in alpha4 KO mice compared with WT. Conversely, in Leu9'Ala mice, DAergic neurons were activated by low ethanol concentrations that did not increase activity of WT neurons. In addition, alcohol potentiated the response to ACh in DAergic neurons, an effect reduced in alpha4 KO mice. Rewarding alcohol doses failed to condition a place preference in alpha4 KO mice, paralleling alcohol effects on DAergic neuron activity, whereas a sub-rewarding alcohol dose was sufficient to condition a place preference in Leu9'Ala mice.

CONCLUSIONS: Together, these data indicate that nAChRs containing the alpha4 subunit modulate alcohol reward. All rights reserved.

Rights and Permissions

Citation: Biol Psychiatry. 2013 Apr 15;73(8):738-46. doi: 10.1016/j.biopsych.2012.09.019. Link to article on publisher's site

Related Resources

Link to Article in PubMed

Journal/Book/Conference Title

Biological psychiatry

PubMed ID

23141806