HTR1A and major depressive disorder: Depressive-like behaviors and cognitive deficitswere assessed in the Sucrose preference and Morris Water Maze (MWM) tests, respectively.Subsequently, effects of the stress model on the serotonergic system (measured by examiningthe concentration of acetylcholinesterase (AChE) and expressions of the serotonintransporter (5-HTT) and serotonin 1A receptor (5-HT1A)) were determined in the hippocampusand prefrontal cortex (PFC), regions implicated in the pathophysiology of MDD.