Steven G. Kohama

Longer lifespan has contributed to the dramatic increase in the number and proportion of the elderly in the general population. The increase in lifespan is also associated with incremental declines in functionality and increased fragility and pathology. Research that identifies and models genetic and environmental factors that underlie the negative aspects of aging are important for identifying underlying mechanisms that can be targeted for amelioration via active intervention.

Steven Kohama heads the Primate Aging Resource at ONPRC, whose aims are to expand and support basic and clinically-related research in the field of aging. Both goals are complementary, as expanding our understanding of basic mechanisms that underlie senescence can help identify interventions that can alleviate age-related functional decline. The recognition that aging research will be critical for addressing the needs of the expanding aged population, coupled with widespread scientific interest, has helped to identify aging as an important cornerstone of research at ONPRC.

Aging research at ONPRC encompasses studies on reproductive senescence, the decline of immunity, vision, and the effects of hormone replacement therapy on behavior and cognition. Models of neurodegeneration involving ischemia and multiple sclerosis are currently being developed. Not surprisingly, some areas of study are multi-disciplinary, such as the exploration of reproductive neuroendocrine aging, where the decline of hormone levels has effects on many target organ systems. Coordination and management of the resource and research projects, coupled with the many tools available at the Center (for example, gene array, proteomics, MRI), provides a dynamic and potent environment for aging research.



Steven Kohama is a Senior Staff Scientist in the Division of Neuroscience and has been Head of the Aging Resource since 1999. He has a B.A. in Biological Sciences from UCLA and a M.S. from CSULA, where he studied the interactions of the reproductive and immune systems. He then studied mechanisms of neuroendocrine aging at the Andrus Gerontology Center at USC, where he received his Ph.D. in the Department of Neurobiology. Post-doctoral work was conducted at ONPRC, concentrating on steroid hormone effects on the brain.




Axthelm MK, Bourdette DN, Marracci GH, Su W, Mullaney ET, Manoharan M, Kohama SG, Pollaro J, Witkowski E, Wang P, Rooney WD, Sherman LS and Wong SW. (2011) Japanese macaque encephalomyelitis: a spontaneous multiple sclerosis-like disease in a nonhuman primate. Ann Neurol. 70(3):362-373.

Bahjat RF, Williams-Karnesky RL, Kohama SG, West GA, Doyle KP, Spector MD, Hobbs TR and Stenzel-Poore M. (2011) Proof of Concept: Pharmacological preconditioning with a Toll-like receptor agonist protects against cerebrovascular injury in a primate model of stroke. J Cerebral Blood Flow Metab. 31:1229-1242.

Kohama SG, Rosene DL and Sherman LS. (2012) Age-related changes in human and nonhuman primate white matter: from myelination disturbances to cognitive decline. AGE. 34:1093-1110.

Cargill R, Kohama SG, Struve J, Su W, Banine F, Witkowski E and Back S. (2012) Astrocytes in aged nonhuman primate brain gray matter synthesize excess hylauronan. Neurobiol Aging. 33(4):860e13-24.


See a full listing of Dr. Steven Kohama's publications.