The Effect of Prenatal Stress on Seizure Threshold and Histomorphometrical Changes on Cerebellar Cortex in NMRI Mice

Stress is a mental or emotional disturbance that occurs in response to external stimuli and can also appear during pregnancy. The aim of this study is to investigate the effect of maternal stress during pregnancy on the cerebellar structure changes and seizure threshold of their offspring. In this experimental study, 20 pregnant female rats were divided into two groups: 1) Non stress group, and 2) Stress group which were under immobilization stress one hour for 14 days. The seizure threshold test in offspring was performed by injecting Pantilen tetrazol drug (PTZ)(n=8). To investigate the cerebellum development, the offspring were divided into three groups. Control group: mothers did not any stress and offspring did not receive PTZ (n=4). Sham group: mothers did not stress but the offspring had received PTZ(n=4). Experimental group: mothers did stress and offispring did receive PTZ(n=4). After the section of cerebellum, the thickness of cerebellum layers and the number of cells in each layer were evaluated. The mean of seizure threshold in the offspring whose mothers were under the stress of pregnancy significantly increased compared to children whose mothers no received stress (p<0.001). In the other side, mean number of purkinje cells in the experimental group significantly decreased compared with the other groups (p<0.001). No significant differences were found in the mean of granular and molecular layers thickness of cerebellum in the experimental group when compared with the other groups(p<0.05). However, mean cellular density in the granular layer of cerebellum in the experimental group significantly decreased compared to other groups (p<0.001). Stress during pregnancy increased the seizure threshold in offspring and caused some developmental and structural disorders in the cerebellar rat offspring.