Effects of short term low dose melatonin and ketamine on depressive behavior and BDNF expression in rats with chronic stress depression
Zhonghua xingwei yixue yu naokexue zazhi December 20, 2017 Haonan Li, Hongwei Sun, Yanyu Wang et al.
In a rat model of depression induced by chronic unpredictable mild stress, melatonin produced antidepressant-like effects comparable to those of ketamine. Rats exposed to 42 days of stress showed depressive-like behavior, indicated by reduced sucrose preference and increased immobility time in the forced swim test. After 14 days of treatment, both melatonin and ketamine significantly decreased immobility time and increased the number of BDNF-positive cells in the prefrontal cortex compared to stressed controls. Melatonin also increased BDNF cell counts more than ketamine did. However, only ketamine, not melatonin, significantly raised GluR1 cell counts. These findings suggest melatonin's antidepressant action may involve upregulation of BDNF.