Limited bedding and nesting increases ethanol drinking in female rats

Area of Science:

• Neuroscience
• Developmental Psychology
• Pharmacology

Background:

• Early life adversities (ELAs), including prenatal opioid exposure (POE) and postnatal adversity, are linked to increased problematic alcohol (EtOH) consumption in adolescence.
• The noradrenergic system, particularly alpha-adrenoceptors, plays a role in alcohol drinking behaviors and their treatment, making it a potential target for understanding ELAs' effects.

Purpose of the Study:

• To investigate the combined and individual effects of POE and limited bedding/nesting (LBN) on adolescent EtOH drinking in rats.
• To determine if ELAs alter alpha-1 and alpha-2 adrenoceptor densities in specific brain regions.
• To explore the role of alpha-2 adrenoceptor inhibition in modulating EtOH intake following ELAs.

Main Methods:

• Rats were exposed to morphine during gestation (POE) and/or limited bedding and nesting (LBN) from postnatal day 3-11 to model ELAs.
• Adolescent rats (PD 31-33) were given intermittent access to 20% EtOH (v/v) to assess drinking behavior.
• Alpha-adrenoceptor densities were quantified using radioligand binding assays in cortex, brainstem, and hypothalamus of EtOH-naïve rats at PD 30 and PD 70.

Main Results:

• Contrary to hypotheses, only LBN significantly increased EtOH intake in female adolescent rats compared to females with POE.
• Neither POE nor LBN exposure affected alpha-1 or alpha-2 adrenoceptor densities in the studied brain regions across adolescent ages.
• These findings indicate a complex interplay between ELA type and sex in influencing adolescent alcohol consumption.

Conclusions:

• The impact of early life adversities on adolescent alcohol drinking is sex-dependent, with limited bedding and nesting alone increasing intake in females.
• Alpha-adrenoceptor densities in the cortex, brainstem, and hypothalamus are not significantly altered by prenatal opioid exposure or postnatal adversity during adolescence.
• These results highlight the nuanced effects of different early life adversities and sex on the development of alcohol drinking behaviors.