Researchers Discover Novel Gene Family Responsible For Pacemaker Activity In Brain...( NEW YORK NY May 28 1998 -- Normal ...)

NEW YORK, NY, May 28, 1998 -- Normal functioning of the heart and the brain depends upon specialized cells that act as pacemakers. These cells generate rhythmic, spontaneous electrical impulses that can control muscle activity, certain automatic functions such as breathing, and behavioral states, including arousal from sleep. Inappropriate pacemaker activity can lead to both inherited and acquired cardiac arrhythmias, and may also underlie various neurological disorders. Two laboratories of the Howard Hughes Medical Institute and the Center for Neurobiology and Behavior at Columbia University report in the May 29, 1998, issue of Cell the discovery that the pacemaker activity in both the heart and the brain is mediated by a common family of novel genes.

The genes, from mouse and human, encode a family of protein ion channels in the cell membranes of nerve and/or muscle cells that help generate pacemaker activity. The channels open and close in response to physiological stimuli and allow the positively charged ions sodium and potassium to cross the cell membrane and initiate an electrical impulse. Specifically, these pacemaker channels keep a stimulated cell active when it would otherwise return to a resting state.

"A pacemaker channel senses that a cell has just fired and tells it that it can't rest, it has to fire another action potential," says Steven Siegelbaum, Ph.D., professor of pharmacology at Columbia University College of Physicians & Surgeons and a Howard Hughes investigator. He and Eric Kandel, M.D., University Professor and senior investigator at the Howard Hughes Medical Institute at Columbia, head the two collaborating labs. Bina Santoro, a postdoctoral fellow in Dr. Kandel's laboratory, and Gareth Tibbs, a postdoctoral fellow in Dr. Siegelbaum's laboratory, led the team that identified the pacemaker channel genes. Other members of the research team are David Liu, Huan Yao, and Dusan Bartsch.

The researchers repor
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Contact: Carolyn Conway
cc328@columbia.edu
212-305-3900
Columbia University Medical Center
29-May-1998