Jahaziel Díaz-Rodríguez^1,2, Yadiel Alicea-Torres^1,2, Diego Nazario-Martínez^1,2, Génesis Rivas-Soto^1,2, Isabel Rivera-Correa^1,2, Eduardo Rosario-Díaz^1,2, Gabriela Serrano- Rivera^1,2, Joseph Torres-Cruz^1,2, Paulette Vázquez-Martínez^1,2, Laura Vicente-Rodríguez, PhD^1,2, Demetrio Sierra-Mercado, PhD²

¹Department of Biology, University of Puerto Rico at Cayey, ²University of Puerto Rico, Medical Sciences Campus, Department of Anatomy and Neurobiology

INTRODUCTION: Concussive brain injuries have raised public health concerns worldwide. These injuries often lead to the loss of motor and cognitive abilities. Notably, this type of injury is more common in women, who frequently experience depression and anxiety following the injury. Rodent models can be valuable for simulating concussions and studying their behavioral consequences. Rearing and grooming are exploratory and innate behaviors, respectively, that can be associated with fear and anxiety in rats. We hypothesized that concussive brain injury would increase grooming and rearing in female rats, which would be consistent with an increase in anxiety-like behaviors.

METHODS: To test this hypothesis, we utilized a closed head injury model involving a weight-drop method to mimic concussive injury in adult female rats. We then assessed grooming and rearing behaviors through home cage recordings (HCR) at various time points after the injury. Specifically, two groups of rats (CHI: n=12, SHAM: n=12) were subjected to 10-minute sessions in the HCR on days 4, 8, 24, and 32 post-injury. In each session, we recorded the grooming bouts and the rearing counts.

RESULTS: Our results indicate that CHI does notaffect exploratory or innate behaviors in female rats, which contradicts our initial hypothesis.

CONCLUSION: Future experiments will incorporate histological approaches to gain insights into how CHI affects the brain. Neuronal activity and inflammation will be measured in brain regions involved in anxiety-like behaviors, such as the insular cortex and subregions of the prefrontal cortex. The findings from this study will help us understand the neuronal mechanisms underlying negative behavioral patterns observed in females following an injury.

IACUC APPROVAL NUMBER: A120121

ACKNLOWEDGEMENTS: NIEHS R21ES034191 to DS-M and FG-V; NINDS R21NS119991, Brain & Behavior Research Foundation Young Investigator grant, PRCTRC Pilot, NIGMS COBRE II, RCMI8G12MD00760, Hispanics in Research Capability (HiREC), and Title V Pilot Project (PiP)  to DS-M; NSF PRCEN fellowships to MC-C, MR-L& HH-M, Neuro-ID fellowship 5R25NS080687 to TS-R, AF-P & GH-B, UPR Med Sci Campus Chancellor’s Office and School of Medicine Deanship.