d-amphetamine withdrawal-induced decreases in brain-derived neurotrophic factor in sprague-dawley rats are reversed by treatment with ketamine

Withdrawal from chronic d-amphetamine (D-AMPH) can induce negative emotional states, which may contribute to relapse and the maintenance of addiction. Diminished levels of brain-derived neurotrophic factor (BDNF), particularly in the hippocampus has been observed after exposure to stress, and recent data indicate that treatment with the N-methyl-d-aspartate (NMDA) receptor antagonist, ketamine may reverse these changes. However, it is unclear whether BDNF levels in the hippocampus or other regions of the limbic system are altered following the stress of D-AMPH withdrawal and it is not currently known if treatment with ketamine has any effect on these changes. The goals of this study were to examine BDNF levels throughout the limbic system following D-AMPH withdrawal and determine whether ketamine treatment would alter D-AMPH-induced changes in BDNF. Sprague-Dawley rats were treated with D-AMPH and BDNF protein examined in the prefrontal cortex, nucleus accumbens, amygdala and hippocampus at 24 h and 4 days of withdrawal. Our data show that at 24 h post-D-AMPH, BDNF levels were increased in the nucleus accumbens and decreased in the hippocampus. At 4d post-D-AMPH, BDNF protein levels were decreased in all areas examined, and these decreases were reversed by treatment with ketamine. These data suggest that diminished BDNF may contribute to the negative affect seen following D-AMPH withdrawal, and that ketamine treatment could offer relief from these symptoms.