The effects of citalopram and low-dose risperidone on memory and anxiety in rats subjected to chronic immobilization stress

Abstract

OBJECTIVES: Many clinical reports describe the beneficial effects of low-dose atypical antipsychotic added to the antidepressants in the management of anxiety disorders. The aim of this study was to evaluate the effect of low-dose atypical antipsychotic when added to antidepressant treatment on cholinergic M 1 receptor expression in the hippocampus and amygdale region in learning and cognitive disorders caused by anxiety. METHODS: The treatments were administered by using different test models on memory, learning, and anxiety, as well as the effect on muscarinic M 1 receptor expression levels were assessed. Citalopram (10 mg/kg/sc) and combination [citalopram and risperidone (1 mg/kg/ sc)] treatments were applied after stress induction using the immobilization model in rats. Animals groups were randomly divided as: control, stress, stress + citalopram, and stress + combination treatment group. Rats in stress groups were immobilized in cages for 4 h a day for 15 days. On days 1-5, groups were subjected to Morris water maze (MWM), open field, and elevated plus maze (EPM) tests. RESULTS: MWM test results have shown that citalopram induces an anxiolytic effect. Low-dose risperidone treatment has increased the antidepressant-like activity of citalopram in all tests. In OFT the number of squares that rats were circulating on the plane was increased and the time spent by the rats on the maze platform was also increased in MWM. In addition to this, the time spent by the rats on the open arms of the EPM test were also increased. Since the combined treatment increased the discovery of the environment and the active behaviour in tests; all those reflected the increase in general activity. Findings also suggest that treatments may play an effective role in altering the expression level of M 1 receptors which are effective in learning and recalling information in the amygdale and the hippocampus. Combination treatment has been shown to provide a meaningful correction of stress-induced memory and learning functions. CONCLUSIONS: These findings indicate that combination treatment may help reduce the stress-induced impairments in cognitive functions. ARTICLE HISTORY

Vitamin E protected the mouse adrenal gland against immobilization stress

“…In a chronic immobilization stress study, stress was applied for 4 h a day for 15 days to male rats. In the elevated plus maze test, the stress group had the highest anxiety index compared to the control group (Aykaç and Sehirli 2018). In this study, immobilization stress also caused severe anxiety-like behavior and depression as compared with unstressed animals.…”