Evaluation Effects of Verapamil as a Calcium Channel Blocker on Acquisition, Consolidation and Retrieval of Memory in Mice
Masoudian, Nooshin;Masoudian, Nahid;Pour, Ali Rashidy;Vafaiee, Abbas Ali;Andalib, Sasan;Vaseghi, Golnaz;
journal of chemical health risks2015Vol. 5pp. -
351
masoudian2015evaluationjournal
Abstract
Many factors are involved in learning and memory processes including brain nuclei, neurotransmittersystems, and the activityof ion channels. Studiesshowedinconsistent effects of calciumchannel blockersonlearning process, especially memory consolidation; however, little is known about their effect on memory acquisition andretrieval. Accordingly,the present study aimed to determinethe effects ofverapamilcalcium channelantagonistas a representative of the phenylalkylamine groupon different stagesof memory and learning processes including acquisition, consolidation and retrievalinmice. In thisexperimental study,150 malealbinomicewith a meanweightof 30gwere used. The mice were trainedina passiveavoidance-learning task(1 mA shockfor 2secondsforevaluation of memory acquisition and consolidationand3 seconds for evaluation of memory retrieval). Theeffectof verapamil(1, 2.5, 5, 10,and20 mg/kg) on memory consolidationand the mosteffective dose of consolidation phaseon memory acquisitionandretrieval was assessed. For the evaluation of memory consolidation, the animals received the drugintraperitoneallyimmediately after training, while for evaluationof memory acquisition and retrieval,the drug was injected one hour beforetraining. Memory retrieval test was performed 48hours after training (the length of time ittookthe animalto enterthe dark part ofthedevice). The results showed thatverapamilinjectionexertedno effect onmemoryacquisition andconsolidation; nevertheless, it was capable to disrupt memory retrieval in 10and20 mgdoses. These results indicate that as a phenylalkylamine calcium channelantagonist, high doses of verapamil can impairmemory.