The Effects of Electroconvulsive Shock on Addiction Behavior in Rats

Cocaine addiction is a widespread problem in the United States, lacking an appropriate treatment. Electroconvulsive shock (ECS) may repair malfunctioning dopamine neurons via induction of synaptic plasticity, providing an alternative treatment for addiction. Sprague­ Dawley rats were trained to seek cocaine, using a conditioned place preference (CPP) procedure. One group of rats received four consecutive days of treatment (ECS or Sham) during extinction. Another group received four (ECS or Sham) treatments applied once every 72 hours during extinction. Both groups were reinstated with a cocaine (10 mg/Kg) injection. A third group of rats also received training for CPP, but were sacrificed after 2, 3, or 4 days of treatment to quantify brain-derived neurotrophic factor (BDNF) levels after ECS treatment. Animals receiving four consecutive days ofECS had a rapid extinction, with significantly lower reinstatement by a cocaine priming injection compared with sham controls. The animals were divided into high and low reinstaters, using a median split analysis (HI Sham = 7; HI ECS = 5; LO ECS = 4). The low reinstaters demonstrated no significant reinstatement whereas the high reinstaters given ECS treatment demonstrated a reinstatement level between that of sham controls and low reinstaters. When ECS was given once every 72 hours, no significant effect on extinction or reinstatement was observed. The BDNF time-course study showed a decrease in BDNF levels at day 3 ofECS treatment in the prefrontal cortex and at day 2 ofECS treatment in the nucleus accumbens. No other brain areas differed statistically. However, a greater sample is needed to draw conclusions regarding BDNF changes during ECS. In sununary, four daily consecutive ECS treatments proved to effectively accelerate extinction and decrease cocaine reinstatement while the 72 hr ECS application did not. ECS may be an effective treatment in an animal model ofaddiction. In drug-addicted humans, newer therapies such as transcranial magnetic stimulation may be a fruitful avenue to explore.