17beta-estradiol and predegenerated nerve graft effect on hippocampal neurogenesis in adult female rats.
OBJECTIVE
The aim of present work was to examine estrogen influence on neurogenesis in the model of predegenerated peripheral nerve grafts implantation into the rat hippocampal dentate gyrus.


METHODS
Experiment was carried out on female rats divided into three experimental groups: NO - non-ovariectomized, OV - ovariectomized and E - heterogeneous group with various 17-beta-estradiol substitution after ovariectomy. Proliferating cells were labeled with BrdU. Brains were subjected to immunohistochemical procedures to visualize nestin, GFAP and estrogen receptors (ERalpha and ERbeta).


RESULTS
Proliferation rate was highest in E groups with estrogen levels resembling that in proestrus phase. Ovariectomy resulted in higher than in NO group number of new neurons, while high hyperestrogenemia worsened the results. The proportions of nestin-labeled cells correlated in similar way with different hormonal state. We found also distinct co-localization of nestin and GFAP in E group (proestrus). It may suggest the presence of radial glia, a potential source of new neurons in adult mammals. Nerve graft induced ERalpha expression at the site of injury in all groups. Distribution of ERbeta in hippocampus was estradiol-dose-dependent and correlated with cell proliferation.


CONCLUSIONS
In our model, 17-beta-estradiol and predegenerated nerve graft implantation had synergistic effect on hippocampal neurogenesis.
Malinowska-Kolodziej
Izabela
I
Department of Physiology, Medical University of Silesia, Katowice, Poland.
Larysz-Brysz
Magdalena
M
Jedrzejowska-Szypulka
Halina
H
Marcol
Wieslaw
W
Wlaszczuk
Adam
A
Lewin-Kowalik
Joanna
J
D000818:Animals; D004268:DNA-Binding Proteins; D004305:Dose-Response Relationship, Drug; D029721:Drosophila Proteins; D004958:Estradiol / Q000097:blood / Q000494:pharmacology*; D047628:Estrogen Receptor alpha / Q000378:metabolism; D047629:Estrogen Receptor beta / Q000378:metabolism; D004967:Estrogens / Q000097:blood / Q000494:pharmacology*; D005260:Female; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006624:Hippocampus / Q000187:drug effects* / Q000502:physiology / Q000601:surgery; D007150:Immunohistochemistry; D007381:Intermediate Filament Proteins / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism; D064231:Nestin; D055495:Neurogenesis / Q000187:drug effects* / Q000502:physiology; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D010052:Ovariectomy; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D012584:Sciatic Nerve / Q000293:injuries / Q000637:transplantation
C109219:Brd protein, Drosophila; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D004967:Estrogens; D005904:Glial Fibrillary Acidic Protein; D007381:Intermediate Filament Proteins; D009419:Nerve Tissue Proteins; C577486:Nes protein, rat; D064231:Nestin; D004958:Estradiol