Individual Nerve Cells Respond to Specific Aspects of Memory

A study revealed that nerve cells widely distributed in the brain respond to specific aspects of memory and may be more specialized than previously thought. Dr. George Ojemann, professor of neurological surgery, published these findings in the January 2002 issue of Nature Neuroscience.

His team studied patients with epilepsy who were awake during surgery to remove parts of the brain responsible for seizures. Researchers asked the patients to recall words, name pictures and describe sounds. Four microelectrodes in the patient’s brain recorded electrical activity as neurons communicated with other cells. The microelectrodes identified impulses from pools of neurons as patients were asked questions that measure stages of memory. Separate activity of individual neurons was deduced based on the shape of their individual discharges.

Researchers were able to identify the behavior of 105 neurons at 57 sites in 26 patients. Ojemann’s team’s largest previous sample was 31 neurons.

A grant from the National Institute of Neurological Disorders and Stroke supported this study, which was a collaborative project with Dr. David Corina, UW professor of psychology.