Neural Plasticity and Addiction

Neuroscientist Dr Mark Thomas recently spoke at Yale University Grand Rounds in the Department of Psychiatry on the topic of "Plasticity in the Neural Circuits for Reward."

Dr Thomas offered data from his research on cutting-edge models of addiction. He summarized findings on how experience can produce long-lasting changes in the function of synapses-“synaptic plasticity”-in reward circuits of the brain. He noted that although many symptoms of psychiatric disorders are a result of maladaptive plasticity in mesolimbic dopamine reward pathways, there is still a shortage of data on the specific nature of this plasticity and the role it may play in influencing cognition and behavior.

Take-home points

• Study of addiction models in rodents is teaching us a great deal about how reward circuits in the mammalian brain can be shaped by experience

• Chronic exposure to addictive drugs like cocaine produces a progressive pattern of synaptic plasticity in reward circuits that can continue to develop well into periods of drug abstinence

• Current research suggests that while some forms of drug-induced reward circuit plasticity are detrimental, others may promote a return to normalcy. If  “beneficial” plasticity could be reinforced, it may provide a means to mitigate addiction relapse