The effects of ketamine on learning and memory function in the pregnant rat' s offspring

Objective To investigate whether pregnant rats exposure to ketamine cause offspring changes in space cognitive abilities and exploration abilities.Methods 3-month Sprague-Dawley female rats ( n =24)were randomly divided into four groups:group N (control group),group K1 (small doses of ketamine group),group K2 ( clinical anesthesia dose of ketamine group),group K3 ( large doses of ketamine group).3-month Sprague-Dawley male rats ( n =4) and female rats were mated at the same cage by the proportion of 2∶ 1.Pregnant mice were treated at tenth day:group N were treated saline with equal-volume to ketamine vein injection; group K1,group K2,group K3 administered vein injection 3,8,20mg/kg of ketamine.Then the 20-day offspring rats'learning and memory were assessed used Open Field Test ( record the time of the offspring in the central case through the number of grid within 2 min ) and Hole Board Test ( Counting the times of offspring stretch into the hole in 5 min) at postnatal days 20.Results In the Open Field Test,the retention time in central check of group N,group K2 and group K3 were (2.45 ± 1.23)s,(6.42 ±2.50)s,(6.41 ±2.19)s.Compared with group N,the retention time in central check of group K2 and group K3 were significantly higher (F=13.42,P＜0.01 ),and group K1 were not significant different ( t =1.33,P＞0.01 ),and the locomotion of group K1,group K2,group K3 were significantly reduced( ( 15.33 ± 6.81 ),( 13.75 ± 5.93 ),( 16.92 ± 6.54 ),F =4.24,P ＜ 0.05 ).In the Hole Board Test,the times of offspring stretch into the hole were not significant different comparing with the control group(F=2.17,P ＞ 0.05 ).Conclusion The dose of ketamine that equivalented clinical anesthesia can affect offspring rats' space cognitive abilities; but the exploring cognitive ability were not significantly influenced. Key words: Ketamine;  Pregnant rats,offspring;  Cognitive function