Long-term effects of intermittent adolescent alcohol exposure in male and female rats

Alcohol is a serious public health concern that has a differential impact on individuals depending upon age and sex. Patterns of alcohol consumption have recently changed: heavy episodic drinking—known as binge-drinking—has become most popular among the youth. Herein, we aimed to investigate the consequences of intermittent adolescent alcohol consumption in male and female animals. Thus, Wistar rats were given free access to ethanol (20% in drinking water) or tap water for 2-h sessions during 3 days, and for an additional 4-h session on the 4th day; every week during adolescence, from postnatal day (pnd) 28–52. During this period, animals consumed a moderate amount of alcohol despite blood ethanol concentration (BEC) did not achieve binge-drinking levels. No withdrawal signs were observed: no changes were observed regarding anxiety-like responses in the elevated plus-maze or plasma corticosterone levels (pnd 53–54). In the novel object recognition (NOR) test (pnd 63), a significant deficit in recognition memory was observed in both male and female rats. Western Blot analyses resulted in an increase in the expression of synaptophysin in the frontal cortex (FC) of male and female animals, together with a decrease in the expression of the CB2R in the same brain region. In addition, adolescent alcohol induced, exclusively among females, a decrease in several markers of dopaminergic and serotonergic neurotransmission, in which epigenetic mechanisms, i.e., histone acetylation, might be involved. Taken together, further research is still needed to specifically correlate sex-specific brain and behavioral consequences of adolescent alcohol exposure

Sex-dependent influence of chronic mild stress (CMS) on voluntary alcohol consumption; study of neurobiological consequences

Alcohol use disorder and depression are highly comorbid, and both conditions exhibit important sexual dimorphisms. Here, we aimed to investigate voluntary alcohol consumption after 6 weeks of chronic mild stress (CMS) in Wistar rats – employed as an animal model of depression. Male and female rats were investigated, and changes in several molecular markers were analysed in frontal cortex (FCx) and hippocampal formation (HF). CMS induced depressive-like responses in the forced swimming test - increased immobility time - in male and female animals, without affecting anhedonia (sucrose preference test) nor motor activity (holeboard); body weight gain and food intake were diminished only among CMS males. Voluntary alcohol consumption was evaluated in a two-bottle choice paradigm (ethanol 20% versus tap water) for 4 consecutive days; females exhibited a higher preference for alcohol compared to male animals. In particular, alcohol consumption was significantly higher among CMS females compared to CMS male animals. Remarkably, similar changes in both male and female animals exposed to CMS were observed regarding the expression levels of NCAM-140 KDa (decrease), GFAP and CB1R expression (increase) within the FCx as well as for HF PSD-95 levels (increase). However, contrasting effects in males and females were reported in relation to synaptophysin (SYN) protein levels within the FCx, HF CB1R expression (a decrease among male animals but an increase in females); while the opposite pattern was observed for NCAM-140 KDa protein levels in the HF. A decrease in CB2R expression was only observed in the HF of CMS-females. The present study suggests that male and female animals might be differentially affected by CMS regarding later voluntary alcohol consumption. In this initial approach, cortical SYN, and NCAM-140 KDa, CB1R and CB2R expression within the HF have arisen as potential candidates to explain such sex differences in behaviour. However, the depression-alcoholism relationship still deserves further investigation

Telegram as a teaching tool in Parasitology and Immunology

Depto. de Microbiología y ParasitologíaFac. de FarmaciaFALSEsubmitte