Investigation of the effect of night-day on learning and memory under isoflurane administration in newborn rats

Aim: The aim of this study is to evaluate the effect of circadian rhythm on learning and memory in isoflurane administrated newborn (d:7) rats.Material and Methods: 42 newborn rats were involved in this study and randomised to four groups. Group-1 (n:11) and Group-3 (n:11) were received to %1.5 concentration of isoflurane for 6 hours. Group-2 (n:10) and Group-4 (n:10) were exposed to room air for 6 hours (controls). Night groups (Group-1 and Group-2) were studied during between 07:00 pm - 01:00 am and day groups (Group-3 and Group-4) were studied during between 07:00 am -13:00 pm. Two hours after cessation of isoflurane anesthesia rats were carried out to their own mother?s sides until learning and memory tests were performed. Five weeks later Morris Water Maze test was performed in order to evaluate learning and memory functions.Results: Learning and memory test results have shown that there was no difference between groups also in platform finding times of initial four days performances (p>0,05). There was no difference in evaluation of standing times on target quadrant in probe trial administration during fifth day (p>0,05).Conclusion: We concluded that circadian rhythm has no effect on memory and learning functions in isoflurane administrated newborn rats.Keywords: Isoflurane, rat, circadian rhythm, learning and memory.