Poster abstracts

Poster number 63 submitted by Michaela Breach

Maternal allergic inflammation has sex-specific effects on oxytocin fiber density in brain regions associated with juvenile social play in rats

Michaela Breach (Neuroscience Graduate Program), Habib E. Akouri (Department of Psychology, The Ohio State University), Claire M. Dodson (Department of Psychology, The Ohio State University), Kathryn M. Lenz (Department of Psychology, Department of Neuroscience, Institute for Behavioral Medicine Research, The Ohio State University)

Abstract:
Background: Maternal immune activation (MIA) increases the offspring’s risk of neurodevelopmental disorders.1 Our rat model of acute allergic MIA produces offspring with symptoms akin to those found in neurodevelopmental disorders, including impaired juvenile social play behavior.2 Here, we further analyzed the behavioral profile found in this model and investigated whether MIA affected oxytocin (OT) and arginine vasopressin (AVP), two neuropeptides crucial for the regulation of social behavior. Methods: Virgin female rats assigned to the MIA group were sensitized to ovalbumin, bred, and allergically challenged on gestational day 15. Control females were administered saline on the same schedule. Male and female offspring were either tested for behavior (ultrasonic vocalizations, allogrooming, and social preference) or euthanized on postnatal day (P)28 for OT and AVP immunofluorescence analysis. OT and AVP neurons were counted in the paraventricular nucleus (PVN), while fiber staining was quantified in the lateral septum (LS), nucleus accumbens (NAc), and directly lateral to the PVN, in the lateral hypothalamic area (LHA). Results: Allergic MIA reduced neonatal USV frequency (F1,36 = 5.6, p = 0.02, eta2 = 0.13). In contrast to our published findings of impaired juvenile play, MIA did not impair sociability in adults (F1,34 = 0.009, ns). Interestingly, MIA reduced OT fiber density in the LS (F1,19 = 7.03, p = 0.02, eta2 = 0.24) and LHA (F1,17 = 5.22, p = 0.04, eta2 = 0.23) of juvenile males but not females. AVP fiber density was unaffected in the LS and LHA (F’s ≤ 2.13, ns). We are currently analyzing other brain regions relevant to sociality, including NAc and PVN. Conclusions: Allergic MIA may impair juvenile play behavior through sex-specific actions on oxytocinergic innervation of the social brain. Future work will investigate the immunological mechanisms underlying oxytocin alterations and social play deficits.

References:
1. Han, V.X., et al., Maternal acute and chronic inflammation in pregnancy is associated with common neurodevelopmental disorders: a systematic review. Transl Psychiatry, 2021. 11(1).

2. Breach, M. R., Dye, C. N., Joshi, A., Platko, S., Gilfarb, R. A., Krug, A. R., ... & Lenz, K. M. (2021). Maternal allergic inflammation in rats impacts the offspring perinatal neuroimmune milieu and the development of social play, locomotor behavior, and cognitive flexibility. Brain, Behavior, and Immunity, 95: 269-286.

Keywords: Maternal Inflammation, Oxytocin, Social Behavior