Therapeutic effects of exercise-accompanied escitalopram on synaptic potency and long-term plasticity in the hippocampal CA۱ area in rats under chronic restraint stress

Objective(s): Administration of antidepressants and exercise are among the therapeutic approaches to chronic stress. Therefore, this study compared the therapeutic effects of different doses of escitalopram, exercise, and exercise-accompanied escitalopram on synaptic potency and long-term plasticity in the hippocampal CA۱ area in rats under chronic restraint stress.Materials and Methods: The rats were allocated to different groups. The chronic restraint stress (۶ hr/day) continued for ۱۴ days. Injection of escitalopram (۱۰ and ۲۰ mg/kg) and treadmill running (۱ hr/day) were performed after the stress induction. The input/output (I/O) functions and LTP induction were evaluated in the hippocampal CA۱ area.Results: The fEPSP slope and amplitude after the LTP induction significantly decreased in the chronically stressed group. However, the serum corticosterone levels had significant enhancement in this group. In addition to serum corticosterone levels, the fEPSP slope and amplitude after the LTP induction were enhanced by exercise, escitalopram ۲۰ mg/kg alone, and exercise-accompanied escitalopram ۱۰ and/or ۲۰ mg/kg in chronically stressed groups.Conclusion: Overall, chronic stress impaired synaptic potency and long-term plasticity. These impairments were effectively reversed by exercise, escitalopram ۲۰ mg/kg alone, and exercise-accompanied escitalopram ۱۰ and ۲۰ mg/kg. However, escitalopram ۱۰ mg/kg alone could not alleviate the memory deficits in chronically stressed subjects. Therefore, exercise with both doses of escitalopram seems to have had additive effects on chronic stress conditions.

Keywords:

Escitalopram , Exercise , Long-term potentiation , Neuronal plasticity , stress