Effects of embryonic inflammatory exposure on hippocampal BDNF gene expression and cognitive function in middle-aged and elderly mice

ObjectiveTo explore the effects of embryonic inflammatory exposure on brain-derived neurotrophic factor (BDNF) protein and mRNA expression in hippocampus and cognitive function in middle-aged and elderly mice.

MethodsFemale rats were intraperitoneally injected with lipopolysaccharide (LPS, 50 μg/kg) or 0.9% sodium chloride solution on the fifteenth to seventeenth day of pregnancy, and the corresponding offsprings were set as LPS group and CON group, with equal male and female mice in each group.The Morris water maze task was completed at 3 and 15 months of age, and the BDNF expression level in hippocampus was detected by Western blotting and real-time quantitative PCR.

ResultsCompared with the CON group at 3 months, the swimming distance in the CON group at 15 months was significantly longer (P < 0.01), and the percentage of swimming distance in the target quadrant and the expression level of BDNF gene in hippocampus were decreased (P < 0.01).Morris water maze scores and BDNF expression levels in the LPS group were worse than those in the CON group in the both age groups.Pearson correlation analysis showed that BDNF gene expression level was negatively correlated with swimming distance in the CON group and LPS group at 15 months of age (P < 0.05), and positively correlated with percentage of swimming distance in the target quadrant (P < 0.05).

ConclusionsEmbryonic inflammatory exposure can aggravate the spatial learning and memory ability of middle-aged and elderly mice, which may be related to the decreased expression of BDNF gene in hippocampus.