The duration of the antidepressant-like effects of a single infusion of brain-derived neurotrophic factor into the medial prefrontal cortex in mice.

Rapid release of brain-derived neurotrophic factor (BDNF) in the medial prefrontal cortex (mPFC) plays a critical role in the rapid and sustained antidepressant actions of ketamine, an N-methyl-d-aspartate receptor antagonist. Although our recent studies demonstrated that a single infusion of recombinant BDNF (100 ng/side) into the mPFC produced rapid antidepressant behavioral responses, the duration of the antidepressant-like effects of the single dose is unclear. Herein, we examined the duration of the antidepressant-like effects of intra-mPFC infusion of BDNF using male C57BL/6 J mice in two different behavioral paradigms namely, despair (forced swim test, FST) and motivation/reward (female urine sniffing test, FUST). Intra-mPFC BDNF infusion significantly decreased immobility time in the FST on days 1 and 7, but not 14 after the infusion. Similarly, BDNF significantly increased the time spent sniffing female urine in the FUST on days 3 and 8, but not 15 after the infusion. Intra-mPFC infusion of BDNF did not affect locomotor activity 2 days after the infusion. These results indicate that the antidepressant-like effects of a single intra-mPFC infusion of BDNF last for approximately one week and that this duration is similar to that of the antidepressant actions of ketamine.