Pondering Epigenetics in Addiction and Depression with Eric Nestler

Why are some people susceptible to becoming addicted to a drug or developing severe depression, while others are not? Professor Eric Nestler of Mount Sinai School of Medicine talks about research suggesting one explanation: epigenetic alterations – enduring changes in the activation of certain genes – in neurons results in long-lasting changes in structure and function of neuronal networks. In addiction, repeated drug exposure results in excessive release of dopamine onto ‘medium spiny neurons’ in a brain region called the nucleus accumbens. Over time this leads to molecular changes in proteins called histones in the nucleus. The histones are part of molecular structures called chromatin upon which DNA is wound. By changing the structure of the chromatin the expression of genes on the associated DNA is altered in ways that contribute to addiction. Dr. Nestler’s laboratory is also elucidating the roles  epigenetic molecular alterations that occur as a result of chronic stress contribute to depression.