Effect of diltiazem on retention and retrieval of memory in young and aged mice.

Diltiazem (DTZ) is widely used in the prophylaxis of hypertension and treatment of angina. The effects of DTZ and other calcium channel blockers on memory have been discussed with several procedures and different theories have been suggested. In the present study, the effect of DTZ on retention and retrieval of memory in young and aged mice was investigated by using the passive avoidance apparatus. For this purpose, after weighting, coding and classifying the mice, they were grouped as follow: test group received electric shock plus DTZ (10 and 30 mg kg(-1), i.p.), blank group received electric shock plus normal saline and control group received only electric shock. In all three groups delay time of leaving the platform for both retention and retrieval test of memory was measured. DTZ was administered immediately after receiving electric shock in the retention test, but in retrieval test DTZ was administered 24 h after receiving electric shock. The results indicated that 30 mg kg(-1) of DTZ impaired retention and retrieval of young mice memory. The 30 mg kg(-1) of DTZ enhanced retention while 10 and 30 mg kg(-1) of it improved retrieval of aged mice memory.