The investigation of the effects of desflurane on neurotoxicity, learning and memory in newborn rats

Aim: The aim of this study is to investigate the effects of desflurane on neurotoxicity, learning and memory in newborn (7 days old) rats.Material and Methods: 33 newborn rats (7 days old) were included and randomized into 4 groups in the study. Group-1 (n:7) and Group-3 (n:11): Desflurane was administered at one minimum alveolar concentration (MAC) for 6 hours (between 7 am and 1 pm) in 450 mL glass jars. Group-2 (n:6) and Group-4 (n:9): 6 L.min-1of oxygen was administered for 6 hours (between 7 am and 1 pm). The rats in Group-1 and Group-2 were sacrified two hours after desflurane anesthesia?s ending to determine apoptotic neurodegeneration, brain tissues were removed and put into 10 % formol. Excised sections were stained with rat specific anticaspase-3 antibody dye and apoptotic cells were counted. The rats in Group-3 and Group-4 were put near their mothers to be looked after in standardized conditions and learning and memory tests were carried out using Morris Water Maze test at the end of the 4th week.Results: In the evaluation of histopathological findings, neuroapoptosis evidences were determined in thalamus paraventricular nucleus, cortex and hippocampus CA1 zones in the rats that were administered 6,8 % concentration of desflurane (Group-1) (p<0,05). In the evaluation of results of the learning and memory tests, platform locating times were found similar among two groups (Group-3 and Group-4) in learning tests performed on the first four day (p>0,05). In probe trial performed at the fifth day; target, left and right adjacent quadrant staying times were found similar among two groups, however, it is determined that desflurane administered group stayed for a longer time at the opposite quadrant (p=0,036).Conclusion: It has been ascertained that the 6,8 % concentration of desflurane is neurotoxic to the newborn rats, but does not affect learning and memory functions.Keywords: Desflurane, rat, neurotoxicity, learning and memory