Mechanical Distention of Organotypic Hippocampal Slice Culture Membranes for High-Throughput <i>In Vitro</i> Modeling of Traumatic Brain Injury

Traumatic brain injury (TBI) results from impact to the head that induces both primary and secondary injuries. Secondary injuries are characterized by downstream inflammation, metabolic dysfunction, and cell death manifest from the inflicting primary injury to the head. Secondary injury offers a window for therapeutic interventions, but the multifaceted nature of secondary injury is complicated, necessitating mechanistic tools to screen the efficacy of such interventions. As such, utilizing animal models to define the features of secondary injury mechanisms is critical for medications development. Various animal TBI models employ specialized equipment to recapitulate both primary and secondary injury aspects of human TBI. The organotypic hippocampal slice culture (OHSC) model offers a biological intermediate between live animal and dissociated cell culture models. In OHSC models, <i>ex vivo</i> tissue containing heterogenous hippocampal cell types is plated upon permeable culture membranes, which have the capacity to be manipulated. We, therefore, repurposed a commercially available impact device to mechanically distend the OHSC culture membrane, effectively inducing an indirect stretch injury to hippocampal tissue. This stretch injury technique causes characteristic secondary injury trauma, such as widespread cell death, loss of neuronal viability, and production of reactive oxygen species, following the initial insult. Importantly, both the impact force and dwell time of the membrane distention are scalable, a modular feature widely employed across other animal TBI models. This OHSC TBI model may lend itself to high-throughput preliminary assessment of therapeutic efficacy for treatment of secondary injury in animal TBI models.