title: Chronic alcohol consumption leads to neurochemical changes in the nucleus accumbens that are not fully reversed by withdrawal.
abstract: Neuropeptide Y (NPY)- and acetylcholine-containing interneurons of the nucleus accumbens (NAc) seem to play a major role in the rewarding effects of alcohol. This study investigated the relationship between chronic alcohol consumption and subsequent withdrawal and the expression of NPY and acetylcholine in the NAc, and the possible involvement of nerve growth factor (NGF) in mediating the effects of ethanol. Rats ingesting an aqueous ethanol solution over 6months and rats subsequently deprived from ethanol during 2months were used to estimate the total number and the somatic volume of NPY and cholinergic interneurons, and the numerical density of cholinergic varicosities in the NAc. The tissue content of choline acetyltransferase (ChAT) and catecholamines were also determined. The number of NPY interneurons increased during alcohol ingestion and returned to control values after withdrawal. Conversely, the number and the size of cholinergic interneurons, and the amount of ChAT were unchanged in ethanol-treated and withdrawn rats, but the density of cholinergic varicosities was reduced by 50% during alcohol consumption and by 64% after withdrawal. The concentrations of dopamine and norepinephrine were unchanged both during alcohol consumption and after withdrawal. The administration of NGF to withdrawn rats significantly increased the number of NPY-immunoreactive neurons, the size of cholinergic neurons and the density of cholinergic varicosities. Present data show that chronic alcohol consumption leads to long-lasting neuroadaptive changes of the cholinergic innervation of the NAc and suggest that the cholinergic system is a potential target for the development of therapeutic strategies in alcoholism and abstinence.
authors.affiliation: Department of Anatomy, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal. Electronic address: pedroper@med.up.pt.
authors.forename: Pedro A
authors.initials: PA
authors.lastname: Pereira
authors.affiliation: Department of Anatomy, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal. Electronic address: jneves@med.up.pt.
authors.forename: João
authors.initials: J
authors.lastname: Neves
authors.affiliation: Department of Anatomy, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal. Electronic address: manelvilela8@gmail.com.
authors.forename: Manuel
authors.initials: M
authors.lastname: Vilela
authors.affiliation: Department of Anatomy, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal. Electronic address: sergioalvesdesousa7@gmail.com.
authors.forename: Sérgio
authors.initials: S
authors.lastname: Sousa
authors.affiliation: Department of Anatomy, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal. Electronic address: catarina_cruz@hotmail.com.
authors.forename: Catarina
authors.initials: C
authors.lastname: Cruz
authors.affiliation: Department of Anatomy, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal. Electronic address: madeira@med.up.pt.
authors.forename: M Dulce
authors.initials: MD
authors.lastname: Madeira
mesh_terms: D000818:Animals; D002795:Choline O-Acetyltransferase / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism; D000431:Ethanol / Q000008:administration & dosage / Q000494:pharmacology*; D007395:Interneurons / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D008297:Male; D020932:Nerve Growth Factor / Q000378:metabolism; D009478:Neuropeptide Y / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism; D009714:Nucleus Accumbens / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D009478:Neuropeptide Y; D000431:Ethanol; D020932:Nerve Growth Factor; D002795:Choline O-Acetyltransferase; D004298:Dopamine; D009638:Norepinephrine
keywords: Acetylcholine; Chronic alcohol consumption; Nerve growth factor; Neuropeptide Y; Nucleus accumbens; Withdrawal