| First Author | Tarren JR | Year | 2017 |
| Journal | Front Mol Neurosci | Volume | 10 |
| Pages | 338 | PubMed ID | 29114204 |
| Mgi Jnum | J:263384 | Mgi Id | MGI:6189271 |
| Doi | 10.3389/fnmol.2017.00338 | Citation | Tarren JR, et al. (2017) Acute Ethanol Administration Upregulates Synaptic alpha4-Subunit of Neuronal Nicotinic Acetylcholine Receptors within the Nucleus Accumbens and Amygdala. Front Mol Neurosci 10:338 |
| abstractText | Alcohol and nicotine are two of the most frequently abused drugs, with their comorbidity well described. Previous data show that chronic exposure to nicotine upregulates high-affinity nicotinic acetylcholine receptors (nAChRs) in several brain areas. Effects of ethanol on specific brain nAChR subtypes within the mesolimbic dopaminergic (DA) pathway may be a key element in the comorbidity of ethanol and nicotine. However, it is unknown how alcohol affects the abundance of these receptor proteins. In the present study, we measured the effect of acute binge ethanol on nAChR alpha4 subunit levels in the prefrontal cortex (PFC), nucleus accumbens (NAc), ventral tegmental area (VTA), and amygdala (Amg) by western blot analysis using a knock-in mouse line, generated with a normally functioning alpha4 nAChR subunit tagged with yellow fluorescent protein (YFP). We observed a robust increase in alpha4-YFP subunit levels in the NAc and the Amg following acute ethanol, with no changes in the PFC and VTA. To further investigate whether this upregulation was mediated by increased local mRNA transcription, we quantified mRNA levels of the Chrna4 gene using qRT-PCR. We found no effect of ethanol on alpha4 mRNA expression, suggesting that the upregulation of alpha4 protein rather occurs post-translationally. The quantitative counting of YFP immunoreactive puncta further revealed that alpha4-YFP protein is upregulated in presynaptic boutons of the dopaminergic axons projecting to the shell and the core regions of the NAc as well as to the basolateral amygdala (BLA), but not to the central or lateral Amg. Together, our results demonstrate that a single exposure to binge ethanol upregulates level of synaptic alpha4( *) nAChRs in dopaminergic inputs to the NAc and BLA. This upregulation could be linked to the functional dysregulation of dopaminergic signalling observed during the development of alcohol dependence. |
