(611) Allergic Maternal Inflammation in Rats Programs Offspring Oxytocin and Vasopressin Innervation in Social Brain Regions.

Thursday, February 9, 2023

4:00 PM – 5:30 PM

Objective: Exposure to inflammatory perturbations, such as infection or allergy, during pregnancy increases the offspring’s risk for neurodevelopmental disorders. Rodent models enable us to investigate the neural mechanisms that may underlie behavioral changes in offspring exposed to inflammation in utero. Our lab has demonstrated that a rat model of allergic maternal immune activation (MIA) induces behavior in offspring resembling that found in neurodevelopmental disorders, including decreased juvenile social play. This study tested whether this fetal programming of altered social behavior may be mediated by reduced innervation of the nonapeptides Oxytocin (OT) and Vasopressin (AVP) in social brain regions such as the Medial Amygdala (MeA) and the Bed Nucleus of the Stria Terminalis (BST).

Study Design: Adult virgin female Sprague Dawley rats (n=7/group) were randomly assigned to be sensitized to ovalbumin with alum adjuvant, or saline. After breeding, pregnant dams were subjected to either OVA challenge or saline control by intranasal infusion on gestational day 15 and were left to give birth undisturbed. On postnatal day 28, 1-2 offspring per sex per litter (n = 40) were sacrificed and brain tissue was collected, fixed, and processed for fluorescence immunohistochemistry of OT and AVP. Fiber fractional area (pixels²) was calculated using Image J software. 2-way ANOVA was used for statistical analysis (alpha=0.05).

Results: A significant interaction revealed that Allergic MIA decreased OT fiber density in the BST of female but not male offspring. There was also a trend for reduced AVP fiber density in the medial anterior BST in both sexes, and a main effect such that males had significantly more AVP than females. Allergic MIA did not decrease OT fiber density in the MeA.

Conclusion:

Allergic MIA may produce sex-specific mechanisms underlying altered social behavior. Future studies will investigate whether pre- or post-natal immunomodulatory treatment may prevent the fetal programming of abnormal social behavior and neuropeptide fiber densities.

Primary & Presenting Author(s)

Sophia Costantine, N/A (she/her/hers)
High School Intern
Department of Psychology and Neuroscience The Ohio State University
Columbus, Ohio, United States

Coauthor(s)

MB
Michaela R. Breach, MS
Neuroscience Graduate Program The Ohio State University
Columbus, Ohio, United States
HA
Habib Akouri, N/A
Department of Psychology and Neuroscience The Ohio State University
Columbus, Ohio, United States
KL
Kathryn M. Lenz, PhD
Department of Psychology, Neuroscience, and Institute for Behavioral Medicine Research The Ohio State University
Columbus, Ohio, United States