Research paperThe effects of gonadectomy and binge-like ethanol exposure during adolescence on open field behaviour in adult male rats

- Gonadectomy in male rats result in impaired spontaneous locomotion in adulthood.
- Adolescent binge-like ethanol shows increased anxiety-like behaviors in adult rats.
- Binge-like ethanol and gonadectomy exert impact on depressive-like behaviors in rats.
- The testicular hormones are potent stimulators of ethanol-induced behaviors.

Binge drinking ethanol exposure during adolescence can lead to long-term neurobehavioural damage. It is not known whether the pubertal surge in testosterone that occurs during adolescence might impact the neurobehavioural effects of early ethanol exposure in adult animals. We examined this hypothesis by performing sham or gonadectomy surgeries on Sprague-Dawley rats around postnatal day (P) 23. From P28-65,the rats were administered 3.0 g/kg ethanol using a binge-like model of exposure. Dependent measurements included tests of open field behaviour, blood ethanol concentrations, and testosterone levels. As adults, significant decreases in open field activity were observed in the GX rats. The open field behaviour of the GX rats was restored after testosterone administration. Binge-like ethanol exposure altered most of the parameters of the open field behaviour, suggestive of alcohol-induced anxiety, but rats treated with alcohol in combination with gonadectomy showed less motor behaviour and grooming behaviour and an increase in immobility, suggesting ethanol-induced depression. These results indicated that testosterone is required for ethanol-induced behavioural changes and that testicular hormones are potent stimulators of ethanol-induced behaviours.