Description
Denson G. Fujikawa 2+ In the early 1980s it was recognized that excessive Ca influx, presumably through 2+ 2+ voltage-gated Ca channels, with a resultant increase in intracellular Ca , was associated with neuronal death from cerebral ischemia, hypoglycemia, and status epilepticus (Siej 1981). Calcium activation of phospholipases, with arachidonic acid accumulation and its oxidation, generating free radicals, was thought to be a potential mechanism by which neuronal damage occurs. In cerebral ischemia and 2+ hypoglycemia, energy failure was thought to be the reason for excessive Ca influx, whereas in status epilepticus it was thought that repetitive depolarizations were responsible (Siej 1981). Meanwhile, John Olney found that monosodium glutamate, the food additive, when given to immature rats, was associated with neuronal degeneration in the arcuate nucleus of the hypothalamus, which lacks a blood-brain barrier (Olney 1969). He followed up this observation with a series of observations in the 1970s that administration of kainic acid, which we now know activates the GluR5-7 subtypes of glutamate receptor, and other glutamate analogues, caused not only post-synaptic cytoplasmic swelling, but also dark-cell degeneration of neurons, when viewed by electron microscopy (Olney 1971; Olney et al. 1974). Dr. Denson Fujikawa is an Adjunct Professor of Neurology at the David Geffen School of Medicine at UCLA, a member of the Brain Research Institute at UCLA and a Staff Neurologist at the Department of Veterans Affairs Greater Los Angeles Healthcare System. His interest in mechanisms of nerve cell death in the brain began during a two-year epilepsy research fellowship with Dr. Claude Wasterlain, from 1981 to 1983. He is a Fellow of the American Academy of Neurology and is a member of the American Epilepsy Society, American Neurological Association, International Society for Cerebral Blood Flow and Metabolism and the Society for Neuroscience.
