protective effects of lithium on sumatriptan-induced memory impairment in mice

lithium is a drug used for the treatment of bipolar disorder. it has several mechanisms of action, and recently it is shown that lithium can antagonize the 5-ht1b/1d serotonin receptors. sumatriptan is a 5-ht1b/1d receptor agonist used for the treatment of cluster headaches and migraine which might cause memory impairment as a potential side effect. in this study, effects of lithium on sumatriptan-induced memory impairment have been determined in a two-trial recognition y-maze and passive avoidance tests. male mice weighing 25-30 g were divided into several groups randomly. in y-maze test, effects of lithium (1,5,10,20,40,80 mg/kg) and sumatriptan (1,5,10 mg/kg) were assessed on memory acquisition, then lithium (0.1,1,10 mg/kg) and sumatriptan (1,10 mg/kg) were studied in passive avoidance test. effects of lithium (1mg/kg) on sumatriptan (10 mg/kg)-induced memory impairment were studied in both of tests. the present study demonstrated that sumatriptan impaired memory in y-maze and passive avoidance tests ( p <0.05, p <0.01, respectively). lithium did not show any significant effect on memory function compared to saline-treated control group in both tests ( p >0.05), but significantly reversed sumatriptan-induced memory impairment in y-maze and passive avoidance tests ( p <0.001, p <0.05, respectively). it is concluded that lithium reverses the sumatriptan-induced memory impairment probably through 5-ht1b/1d receptors antagonism.