Effects of different doses of ketamine on brain-derived neurotrophic factor and tyrosine receptor kinase B in hippocampus in mentally depressed rats

Objective To investigate the effects of different doses of ketamine on brain-derived neurotrophic factor (BDNF) and tyrosine receptor Idnase B (TrkB) in the hippocampus in mentally depressed rats.Methods Fifty male Wistar rats weighing 180-220 g were randomly divided into 5 groups ( n = 10 each): group control (group C) and groups K1-4 ketamine 2.5, 5.0, 10.0 and 20.0 mg/kg. On the 1st day the animals were forced to swim for 15 min. On the 2nd day ketamine 2.5, 5.0, 10.0 and 20.0 mg/kg were given iniraperitoneally in groups K1-4 respectively at 30 min after administration. The immobility time of the rats during the forced swimming test was recorded. The animals were then decapitated. The hippocampus was harvested for determination of BDNF and TrkB levels. Results Ketamine significantly decreased the immobility time during forced swimming test in a dose-dependent manner. The BDNF and TrkB levels in the hippocampus were significantly increased in K, and K4 groups as compared with group C, and K1 and K2 groups. Conclusion The increased levels of BDNF and TrkB in the hippocampus are involved in the dose-dependent antidepressant effect of ketamine. Key words: Ketamine;  Depressive disorder;  Brain-derived neurotrophic factor;  Receptor proteintyrosine kinases