Altered social recognition memory and hypothalamic neuropeptide expression in adolescent male and female rats following prenatal alcohol exposure and/or early-life adversity

Abstract

Prenatal alcohol exposure (PAE) and early-life adversity (ELA) both negatively impact social neurobehavioral development, including social recognition memory. Importantly, while individuals with PAE are more likely to experience ELA, relatively few studies have assessed the interaction of these two early insults on adolescent social behavior development. Here, we combine animal models of PAE and ELA to investigate both their unique and interactive effects on social neurobehavioral function in early and late adolescent male and female rats. Behavioral testing was followed by assessment of hypothalamic expression of oxytocin (OT) and vasopressin (AVP), key neuropeptides in the regulation of social behavior. Our results indicate that PAE and ELA have unique sex- and age-specific effects on social recognition memory and OT/AVP expression, with more pronounced neurobehavioral changes observed in males than in females in both early and late adolescence. Specifically, ELA impaired social recognition in early adolescent females regardless of prenatal treatment, while males showed deficits in both early and late adolescence in response to unique and interactive effects of PAE and ELA. Neurobiological data suggest that these perinatal insults differentially impact the OT and AVP systems in a sexually dimorphic manner, such that the OT system appears to be particularly sensitive to PAE in males while the AVP system appears to be more vulnerable to ELA in females. Taken together, our data provide novel insight into how the early postnatal environment may mediate outcomes of PAE as well as the power of animal models to interrogate the relationship between these pre- and postnatal insults.

Keywords: Adolescence; Early life adversity; Oxytocin; Prenatal alcohol exposure; Social behavior; Social recognition memory; Vasopressin.