Distinct and Overlapping Patterns of Acute Ethanol-Induced C-Fos Activation in Two Inbred Replicate Lines of Mice Selected for Drinking to High Blood Ethanol Concentrations

Abstract

The inbred high drinking in the dark (iHDID1 and iHDID2) strains are two replicate lines bred from the parent HS/Npt (HS) line for achieving binge levels of blood ethanol concentration (≥80 mg/dL BEC) in a four-hour period. In this work, we sought to evaluate differences in baseline and ethanol-induced c-Fos activation between the HS, iHDID1, and iHDID2 genetic lines in brain regions known to process the aversive properties of ethanol. Methods: Male and female HS, iHDID1, and iHDID2 mice underwent an IP saline 2 3 g/kg ethanol injection. Brain sections were then stained for c-Fos expression in the basolateral/central amygdala (BLA/CeA), bed nucleus of the stria terminals (BNST), A2, locus coeruleus (LC), parabrachial nucleus (PBN), lateral/medial habenula (LHb/MHb), paraventricular nucleus of the thalamus (PVT), periaqueductal gray (PAG), Edinger–Westphal nuclei (EW), and rostromedial tegmental nucleus (RMTg). Results: The iHDID1 and iHDID2 lines showed similar and distinct patterns of regional c-Fos; however, in no region did the two both significantly differ from the HS line together. Conclusions: Our findings lend further support to the hypothesis the iHDID1 and the iHDID2 lines arrive at a similar behavior phenotype through divergent genetic mechanisms.

Corticosterone Levels and Glucocorticoid Receptor Gene Expression in High Drinking in the Dark Mice and Their Heterogeneous Stock (HS/NPT) Founder Line

“…Because selective breeding principally changes the frequencies of genes affecting the targeted trait, any other differences between the selected line and its non-selected founder line may reflect coordinate genetic influences on the two traits. Thus, comparisons between HDID-1 and the founder HS/NPT lines have successfully been used to investigate the genetic and molecular determinants of high-risk drinking and identify potential pharmacotherapies for AUD ( Cozzoli et al, 2012 , 2016 ; Iancu et al, 2013 , 2018 ; Crabbe et al, 2017 , 2020 ; Ferguson et al, 2018 , 2019 ; Grigsby et al, 2020 ; Ozburn et al, 2020 ; Pozhidayeva et al, 2020 ; Robinson et al, 2020 ; Savarese et al, 2020 ). To test the effects of GR antagonism within this selectively bred line, HDID-1 mice were given both mifepristone, a non-selective steroid hormone receptor antagonist, and CORT113176, a specific GR antagonist.…”

Chemogenetic inhibition of corticotropin-releasing factor neurons in the central amygdala alters binge-like ethanol consumption in male mice.

“…Additional studies should delineate the sex differences in the impact of silencing of CRF neurons on ethanol consumption (Schwandt et al, 2016). Previous reports show that G i/o -DREADDs in CRF neurons functionally inhibit the activity of CRF+ cells in vitro (Pleil et al, 2015), but herein, the function of G i/o -DREADDs in CRF neurons was analyzed using c-Fos, as previous studies have shown ethanol administration causes upregulation of c-Fos in the CeA (Leriche et al, 2008;McBride, 2002;Morales et al, 1998;Robinson et al, 2020). CNO administration prior to IP ethanol reduced the number of c-Fos+ cells within the CeA, suggesting that G i/o -DREADD activation inhibited CRF-neuronal activity stemming from an ethanol injection.…”

“…Mice were given CNO 30 min prior to administration of 1.5 g/kg ethanol ip (13% v/v in 0.9% saline). This dose of ethanol has previously been indicated to increase c-Fos within the amygdala and simulates BECs comparable to those achieved within the DID paradigm (Marshall et al, 2015;McBride, 2002;Robinson et al, 2020). Two hours post ethanol injections, mice were euthanized via perfusion.…”

“…Every fourth section collected from c-Fos experimental brains was used for c-Fos immunoreactivity detection similar to previous description of immunohistochemical procedures (Robinson et al, 2020). Briefly, sections were rinsed in 0.1 M PBS before submersion in goat serum (PBS/0.1% triton-X/3% serum; Vector Laboratories; Burlingame, CA) for 30 min to reduce background staining.…”

Transcriptome analysis of alcohol dependence and stress interactions in the nucleus of the solitary tract

“…Acute and chronic exposure to ethanol have been shown to activate the NTS as measured by c-Fos induction [16][17][18][19]. Activity within the NTS has been associated with substance use withdrawal [20]. Activation and inhibition of the NTS regulate both stress reactivity and alcohol consumption [4,12,13,21].…”