Stimulatory effect of gonadal hormones on fetal rat hippocampal neural proliferation requires neurotrophin receptor activation in vitro

To determine the effects of gonadal hormones on proliferation of the hippocampal neural cells, which are of importance in learning and memory function. 17β-Estradiol or testosterone was added to the culture at various concentrations. Their proliferation and protective effects on the neural cell were determined with BrdU, flow cytometry and MTT assay. Effects of the gonadal hormones on brain-derived neurotrophic factor (BDNF) expression were determined using ELISA and RT-PCR respectively. 17β-Estradiol and testosterone at 20 nM or higher concentrations significantly increased the neural cell proliferation and viability, and induced increasing in the S phase arrest which is essential for cell proliferation. Both estradiol and testosterone significantly increased the neural cell expression of cellular mature BDNF and BDNF mRNA. Effect of testosterone on hippocampal neural proliferation was blocked by Trk neurotrophin receptor inhibitor. 17β-Estradiol and testosterone promoted hippocampal neural proliferation and improved cell viability in vitro. The effect of testosterone on hippocampal neural cell proliferation required neurotrophin receptor activation.