John M. Hallenbeck, M.D.

Headshot of John M. Hallenbeck
Scientist Emeritus
Stroke Branch

BG 10 RM 5B02

Dr. Hallenbeck received his M.D. degree from the University of Pennsylvania. After a medical internship and neurology residency at the University of Michigan, he entered the United States Navy. At the Naval Medical Research Institute his research focused on CNS decompression sickness and air embolism and later the study of inflammatory and immune mechanisms in acute brain ischemia. In 1983, he was appointed Chief of the Navy's neurology training program at the National Naval Medical Center and Professor, Vice-Chairman and Chairman for Research in the Department of Neurology, Uniformed Services University of the Health Sciences. In 1991 he came to the NINDS as Chief of the newly created Stroke Branch. He received the Mihara Cerebrovascular Disorder Research Prize. Dr. Hallenbeck's laboratory is studying the cellular regulation of ischemic tolerance and inflammatory and immune mechanisms in the initiation and progression of stroke.

The Clinical Investigations Section of the Stroke Branch conducts translational research on stroke prevention and stroke treatment. In spontaneously hypertensive, stroke-prone rats, we are studying ways of preventing development of spontaneous brain infarcts. This work is focused on immunologic approaches that suppress the endothelial activation produced by inflammatory cytokines such as TNF and IL-1. Mucosal tolerization to E-selectin targets immunomodulation to vascular segments that are becoming activated and suppresses spontaneous strokes and hemorrhages. This work is being translated into clinical trials.

We also study endogenous neuroprotective mechanisms that induce tolerance to hypoxia and ischemia in brain cells. This work is focused on the intracellular signaling pathways and expressed genes that regulate tolerance to hypoxia and ischemia in hibernating animals (a model of natural tolerance), and in preclinical stroke models and primary cultures of brain microvessel endothelial cells, astrocytes, microglia, cortical neurons and transformed cell lines that have been preconditioned to induce tolerance (models of induced tolerance). Multifunctional regulatory mechanisms that are conserved in the several tolerance models are of particular interest. Findings in preclinical models that have robust potential to treat stroke are candidates for translation into proof of concept clinical trials.