Prenatal Immobilization Stress-Induced Spatial Memory, Depression and Anxiety-Like Behavior Deficit on the F1 Generation in the Female Mice: Possible Involvement of the Brain-Derived Neurotrophic Factor

The prenatal stress during pregnancy has a wide variety of negative effects on the offspring behaviors. As such, in the present study the effect of prenatal immobilization stress was investigated on the brain BDNF level, spatial memory, anxiety and depression-like behavior in the F1 generation female NMRI mice. Twenty female pregnant mice were randomly allocated to stress and control groups (n = 10/group). The stress group was placed in PVC cylinders (2.5 cm in diameter and 20 cm in length) for one hour/day until the 15th day of pregnancy. The female F1 offspring was nursed by their mothers until reaching 25-30 g (9-10 weeks) which was tested for spatial memory, anxiety and depressive-like behavior using Barnes Maze, elevated plus-maze and forced swimming test, respectively. Also, the brain BDNF level was assessed by the ELISA method. Mice that underwent prenatal restraint stress exhibited impaired spatial memory in the Barnes Maze, which the time and distance to achieve the target hole and the number of errors in the female adult offspring increased than the control group. In the elevated plus-maze, the animals that underwent prenatal restraint stress spent less time in the open arms of the maze and reduced entering the open arms, compared to the control group. In addition, stress caused a significant decrease in swim time and a significant increase in float time for the female adult offspring compared to the control group. The brain BDNF concentration also decreased significantly in the stress group compared to the control group. This data suggests that prenatal stress may impair spatial memory and induce anxiety and depressive-like behavior in the adult offspring female mice via reducing brain BDNF.