Protective effects of estradiol on hippocampus during aging.

SARAVIA F; BEAUQUIS J; PIETRANERA L; ROIG P; DE NICOLA AF

Madrid, España

Congreso; 2nd Iberoamerican Congress on Neuroimmunomodulation; 2007

International Society for Neuroimmunomodulation

During aging the hippocampus experiences structural, molecular, and functional alterations. Protection from age-related disorders is provided by several factors, including estrogens. Since aging defects start at middle age, we studied if 17 b-estradiol (E2) protected the hippocampus at this age period. Middle age male C57Bl/6 mice were treated with E2 during 10 days to study cell proliferation in the dentate gyrus (DG) by bromodeoxyuridine (BrdU) incorporation. A pronounced depletion of BrdU+ cells in the DG was found in untreated mice, accompanied by hippocampal astrocytosis, neuronal loss in the hilus and lipofuscin deposits. Mice receiving E2 showed increased proliferation while the other aging parameters were remarkably attenuated. Cell migration in the DG was unaffected by E2 in mice treated during 2 months but they exhibited increased staining for doublecortin, a marker for differentiating neurons. Interestingly, E2 stimulated progenitor proliferation and differentiation towards a neuronal lineage. This result, in conjunction with recovery from aging indicators supports a wide range protection of the hippocampus of middle age male mice by estrogenic hormones.