Altered activity within the social behavior neural network in adolescent rats following prenatal alcohol exposure and/or early-life adversity

Social behavior relies on the dynamic, complex, and coordinated activity of a highly conserved "social behavior neural network," which includes the olfactory bulb (OB), piriform cortex (PCX), lateral septum, medial prefrontal cortex (mPFC), amygdala, paraventricular nucleus of the hypothalamus (PVN), and ventral hippocampus. Prenatal alcohol exposure (PAE) is known to disrupt social behavior development, leading to lifelong social functioning impairments. Individuals with PAE are at heightened risk of experiencing early-life adversity (ELA), which independently affects social behavior development; however, little is known about the combined effects of PAE and ELA on social behavior.

We previously demonstrated that PAE and ELA impact social recognition memory throughout adolescence; here, we combine animal models of PAE and ELA to gain insight into both independent and interactive effects of these insults on social behavior network neural activity in both early and late adolescent male and female rats. We measured neural activity (c-fos mRNA expression) across the network following social recognition memory testing.

Our findings indicate that both PAE and ELA are associated with altered neural activity in regions supporting social recognition memory, notably the OB, PCX, mPFC, amygdala, and PVN. The direction of these effects and specific regions impacted vary by sex and age at assessment. Importantly, different brain areas exhibit distinct sensitivities to each type of insult, with PAE generally resulting in hypoactivity of the amygdala and ELA altering mPFC activity.

These data contribute to a more complete social neurobehavioral profile, accounting for both PAE and ELA, to support earlier diagnoses and interventions.