453 Ketamine Promotes Sustained Brain-Derived Neurotrophic Factor Levels in the Corticoaccumbens Circuit

Abstract

OBJECTIVES/GOALS: Neuropsychiatric disorders classified as synaptopathies are marked by a glutamate-associated hypofrontality which impacts decision making and impulsivity. We hypothesized that behavioral efficacy of the psychoplastogen ketamine is mediated in part through lasting promotion of markers of synaptic strength in corticoaccumbens circuit. METHODS/STUDY POPULATION: Male, Sprague-Dawley rats received an intraperitoneal (i.p.) injection of saline, single ketamine (10 mg/kg; 1x/day), or repeated ketamine (10 mg/kg; 1x/day for three days). Twenty-four hrs following the dosing regimen, animals were euthanized, and brains dissected to harvest corticoaccumbens structures including the medial prefrontal cortex (mPFC) and the nucleus accumbens (NAc). mRNA was extracted and converted to cDNA. Levels of brain derived neurotrophic factor (BDNF) exon II mRNA were quantified using reverse transcriptase polymerase chain reaction (RT-PCR); cyclophilin A (PPIA) was used as a loading control. Gene expression differences in ketamine-treated rats were identified versus saline-treated rats. BDNF protein levels were quantified using capillary-electrophoresis immunoblotting. RESULTS/ANTICIPATED RESULTS: Repeated, but not single, ketamine administration decreased mPFC, but increased NAc, BDNF exon II mRNA levels versus saline (p<0.05). Single and repeated ketamine administration increased NAC BDNF protein (p<0.05), while both dosing paradigms induced a trend towards an increase in mPFC BDNF levels. DISCUSSION/SIGNIFICANCE: We discovered a dosing regimen-dependent and sustained effects of ketamine administration on BDNF levels in the rodent brain. Taken together, ketamine-mediated BDNF levels may sustain synaptic strengthening mechanisms supporting future investigation into the utility of ketamine for diseases characterized by synaptopathies.