Possible mechanisms of prenatal cold stress induced-anxiety-like behavior depression in offspring rats

Environmental factors and prenatal stress have long-term effects on offspring behavior, physical development, hypothalamic-pituitary-adrenal (HPA) axis regulation, immune activity, and disease susceptibility. To further understand the effects of prenatal cold stress on offspring, we investigated the behavior change; the expression of glucocorticoid receptor (GR), mineralocorticoid receptor (MR), brain-derived neurotrophic factor (BDNF), insulin-like growth factor 1 receptor (IGF1R), neuronal nuclei (NEUN), glial fibrillary acidic protein (GFAP), corticotropin-releasing hormone receptor 1 (CRHR1), Gamma-aminobutyric acid B receptor, 2 (GABAB2) proteins in hippocampus; the ratio of CD4/CD8 lymphocyte subsets and the level of norepinephrine (NE), dopamine (DA) in the peripheral blood of weaned offspring rats using behavioral tests and biology analysis methods. The results showed that prenatal cold stress affected offspring HPA axis activity, inhibited the expression of MR, BDNF and IGF1R in the hippocampus of male offspring, and lowered the expression of GR in female offspring. The expression levels of NEUN and GFAP in the hippocampus of male and female offspring were also reduced, which may have affected the growth and development of neurons. Moreover, prenatal cold stress inhibited the expression of CRHR1 and GABAB2 in the hippocampus of male offspring, leading to decreased anxiety-like behavior in offspring; a reduced ratio of CD4 and CD8 lymphocyte subsets in the peripheral blood of male offspring; and inhibition of offspring cell immunity. In summary, prenatal cold stress inhibits the growth and development of hippocampal neurons in weaned offspring rats, and induces offspring anxiety-like behavior reduced.