A new target for Parkinson's
For years, scientists knew that Parkinson's resulted from a loss of the neurotransmitter dopamine in the basal ganglia of the brain. No one, however, understood how this loss caused the tremor, muscular rigidity, and slowness of movement experienced by patients. Studying animals with a Parkinson's-like condition, neurologist Mahlon DeLong found that basal ganglia cells involved in movement control were firing excessively. He and his colleagues used microelectrode-recording techniques to pinpoint the exact location of this abnormal cell activity. They then demonstrated that surgical inactivation of the cells brought Parkinson's symptoms under control. These discoveries revolutionized understanding of Parkinson's and contributed to the revival and development of surgical treatments for this and other movement disorders. The discoveries also provided targets for deep-brain stimulation, which controls abnormal firing of cells through delivery of electrical impulses, much like a cardiac pacemaker.