The Effects of Inhalation Anesthetics on the Memory of Rats

Park, Chong Min

Abstract

The effect of inhalation anesthetics on memory was studied using 26 male Sprague-Dawley rats. In the control group the trained rats were tested the first performance time of T-maze and left them to anesthetic chamber for 120min. and checked second performance time 24hours later (Group A). For the experimental group the first performance time was tested and animals were exposed to the anesthetics (1% Halothane with N20:02=2:1) for 120min. and checked second performance time 24hours after cessation of exposure to evaluate retrograde amnesia (Group B). For the test of anterograde amnesia (Group C) rats were anesthetized before test the first performance time and checked second performance time 24hours later. The mean perfor- mance ratio (II/I) (i.e., I is the score in the first performance time and II is the score in the second performance time) was compared between anesthetized and non-anesthetized control group. In the group A the ratio was 102.8+/-19 but in group B it was 96.4+/-13 during anesthesia, 79.+/-19 after anesthesia and 92.3+/-11 in overaU anesthetized group, and was 100.2+/-17 in group C. All data of group B were significantly different with group A (p<0.01). But no statistical difference between group C and A was observed (p=0.174). These results suggest that post- training exposure to volatile anesthetics facilitates memory and no anterograde amnesia observed by pretraining exposure. These may be volatile anesthetics facilitate memory by enhancement of memory consolidation and/or retention or interference reduction.