ABS 038: Systematic comparison of LBN approaches across institutions reveals distinct phenotypes in rodents

Su, Allison. ¹ , Regier, Elaina. ¹ , Win, Vishal. ¹ , Isabellah, Nikitah. ¹ Opendak., Maya ¹ ² ³

¹ Kennedy Krieger Inst., Baltimore, MD USA
² Solomon H. Snyder Dept. of Neuroscience, Johns Hopkins University Sch. of Medicine, Baltimore, MD USA
³ Kavli Neurodiscovery Institute, Baltimore MD USA

Van Wickle (2025) Volume 1, ABS 038

Introduction: Early-life adversity (ELA) impacts social development and neural trajectory, which leads to disrupted social behavior linked to autism, anxiety, and depression. The scarcity-adversity model in rodents, which employs low-bedding (LB) conditions, mimics ELA by inducing maternal neglect and maltreatment. However, current models introduce biological confounds, such as altered gut microbiota from fecal exposure, which may affect the results. This study seeks to standardize the LB model used in studies by evaluating whether moderate bedding deprivation (500cc corncob bedding) can elicit similar neural and behavioral changes as severe bedding deprivation (100cc), thereby addressing gut microbiome confounds and enhancing experimental reproducibility.

Methods: Long Evans rat dams and pups were assigned to control, severe LB (100cc), and moderate LB (500cc) conditions. Maternal behaviors were recorded from postnatal days (PN) 8–12 using BORIS software to assess maltreatment patterns On PN13, pups underwent a maternal approach test, analyzed via EthoVision, to evaluate social behavior. Neural activity in the basolateral amygdala (BLA), a region associated with social reward circuits, will be quantified through c-Fos staining, a protein which marks neuronal activity, and image analysis. Outcomes will be statistically compared using ANOVA.

Results: Maternal behavior analysis indicates similar patterns between the 100cc and 500cc conditions. Likewise, preliminary behavioral assessments suggest perturbed social behavior in pups from both conditions. ANOVA tests are needed to confirm statistical significance. BLA activity analysis is ongoing.

Discussion: This study aims to validate the 500cc bedding condition as a reliable ELA model and bridge findings from severe and moderate adversity conditions. Results may establish a standardized approach for ELA research and better pinpoint specific brain regions linked to social behavior disruptions. By addressing confounds and refining methodologies, this work advances the understanding of neural mechanisms underlying ELA and strengthens interventions targeting social disorders.