A stream of electrical pulses delivered to the brain's reward center curbs the power of a cocaine injection to spur rats to drug seeking.
Dr. R. Christopher Pierce of Boston University School of Medicine and colleagues trained rats to press a lever to self-administer the drug, then weaned the rats off that behavior by withholding the drug. Normally, after rats exposed to this protocol receive a priming injection of cocaine, they resume lever pressing, a response that mimics human relapse to drug abuse. In the Boston experiment, rats that received 2 hours of deep brain stimulation to the shell area of the nucleus accumbens (NAc) immediately following the priming injection pressed the lever about half as much as control animals.
Dr. Pierce says his team's findings suggest that deep brain stimulation of the NAc shell holds promise as a therapy for severe cocaine addiction. Deep brain stimulation of a different brain region has benefited patients with Parkinson's disease, and the technique is also being tested as a potential therapy for severe depression that does not improve with medication.
Journal of Neuroscience 28(35):8735–8739, 2008. [Full Text (PDF, 266KB)]