Perelman School of Medicine at the University of Pennsylvania

Johnson Lab

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Research

Our main areas of research include:

Evolving Neuropathologies of TBI

Interest in TBI has increased in recent years, in large part driven by reports of a possible link between TBI, including repetitive mild TBI or “concussion”, and progressive neurodegenerative pathologies. As part of collaborative efforts, our group examines the potential associations and mechanisms of TBI induced degeneration over time. Of particular interest, our group has been exploring potential mechanisms of white matter degeneration temporally post-injury, including using unique in vivo models, advanced neuroimaging and serum biomarker approaches for the non-invasive detection of pathologies.

TBI and the Blood Brain Barrier:

The blood brain barrier (BBB)  is a complex structural and functional barrier between the peripheral circulation and brain parenchyma that ensures a highly regulated environment needed for CNS function. Acute BBB disruption has long been appreciated as an almost ubiquitous consequence of moderate-severe TBI and is associated with poor outcome. Notably, increasing evidence now indicates BBB permeability may also occur with mild TBI or concussion. A focus of our lab is to investigate how TBI causes BBB dysfunction across the spectrum of TBI severity and over time.

Using novel and translational approaches we aim to understand the detrimental processes driving pathological permeability of the brain vasculature after TBI, with a view to developing novel therapeutic approaches.

Post Traumatic Epilepsy

Post-traumatic epilepsy (PTE) represents a frequent and debilitating complication of TBI that can present in the weeks, years or in some cases, decades post-injury. TBI comprises complex and variable acute pathologies, yet the specific mechanisms that lead to epileptogenesis are poorly understood. Notably, recent and increasing data indicate that TBI is capable of triggering evolving neuropathological processes that can continue beyond the acute phase, for months and even years post-injury.

Our lab is currently researching the clinically-relevant neuropathological changes of PTE to inform on mechanisms of epileptogenesis following TBI. Through characterizing the temporal neuropathology of human post-traumatic epileptogenesis, in parallel with pre-clinical studies, we hope to provide insight to inform strategies targeted towards the prevention and management of PTE.