Distinct Chrna5 mutations link excessive alcohol use to types I/II vulnerability profiles and IPN GABAergic neurons.

Léa Tochon, Nadia Henkous, Morgane Besson, Uwe Maskos, Vincent David
Transl Psychiatry. 2024-11-06; 14(1):
DOI: 10.1038/s41398-024-03164-8

PubMed

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1. Transl Psychiatry. 2024 Nov 6;14(1):461. doi: 10.1038/s41398-024-03164-8.

Distinct Chrna5 mutations link excessive alcohol use to types I/II vulnerability
profiles and IPN GABAergic neurons.

Tochon L(1), Henkous N(2), Besson M(3), Maskos U(3), David V(4).

Author information:
(1)Univ. Bordeaux, CNRS, EPHE, INCIA, UMR 5287, Bordeaux, France.
.
(2)Univ. Bordeaux, CNRS, EPHE, INCIA, UMR 5287, Bordeaux, France.
(3)Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Integrative
Neurobiology of Cholinergic Systems, Paris, France.
(4)Univ. Bordeaux, CNRS, EPHE, INCIA, UMR 5287, Bordeaux, France.
.

Genome wide association and animal studies have implicated genetic variations in
CHRNΑ5, encoding the α5 subunit-containing nicotinic acetylcholine receptors
(α5*nAChRs), as a risk factor for developing alcohol use disorders (AUDs). To
understand how α5*nAChR mutations may influence alcohol (EtOH) drinking
behavior, we used a two-bottle choice procedure with intermittent access to
alcohol in male and female transgenic mice expressing either the highly frequent
human single nucleotide polymorphism (α5SNP/rs16969968) or a deletion of the
Chrna5 gene (α5KO). AUDs-related preconsommatory traits (anxiety,
sensation-seeking and impulsivity) were assessed with a battery of relevant
tasks (elevated-plus maze, novel place preference and step-down inhibitory
avoidance). The implication of the α5-expressing IPN GABAergic neurons in AUDs
and related behavioral traits was verified using neurospecific lentiviral
(LV)-induced reexpression of the α5 subunit in α5KOxGAD-Cre mice. Both α5SNP and
α5KO mice showed over-consumption of EtOH, but displayed opposite vulnerability
profiles consistent with Cloninger’s subtypes of human AUDs. α5SNP mice showed
Type I-like characteristics, i.e., high anxiety, novelty avoidance, whereas
α5KOs exhibited Type II-like features such as low anxiety and high impulsivity.
LV re-expression of the α5 subunit in IPN GABAergic neurons restored the control
of EtOH intake and improved the impulsive phenotype. We demonstrate that the SNP
(rs16969968) or null mutation of Chrna5 result in increased volitional EtOH
consumption but opposite effects on anxiety, novelty-seeking and impulsive-like
behaviors that match Cloninger type I and II of AUDs, including sex-related
variations. IPN GABAergic neurons expressing α5*nAChRs play a key role in
limiting both EtOH drinking and motor impulsivity.