title: Regional, laminar and cellular distribution of immunoreactivity for ERbeta in the cerebral cortex of hormonally intact, postnatally developing male and female rats.
abstract: Estrogen influences cerebral cortical development. Among the receptors involved are classical (ERalpha) and beta (ERbeta) intracellular estrogen receptors. In the first 2 weeks of postnatal life, cortical ERalpha is transiently expressed at much higher levels than in adulthood. In this study, development of ERbeta was examined by mapping ERbeta immunoreactivity in relation to major cortical regions, layers and cell types in postnatal male and female rats that were 1-28 postnatal days (PND) old. These studies revealed that ERbeta-immunoreactive nuclei were present in the allocortices on PND 1 but were not detected in isocortex until PND 7. Allocortical labeling was also higher on PND 1 than at all later ages, while in isocortical areas low numbers of ERbeta nuclei were seen on PND 7 that rose to higher, near adult densities by PND 21. Finally, double labeling showed that ERalpha was expressed mainly in neurons immunopositive for calretinin, while ERbeta was localized predominantly in parvalbumin-immunoreactive cells. Thus, the postnatal cortical developments of ERbeta and ERalpha occur according to different timetables, different patterns and in association with different cortical cells. It thus seems it likely that the two also make distinct contributions to postnatal cortical development and/or sexual differentiation.
authors.affiliation: Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY 11794-5230, USA. mkritzer@notes.cc.sunysb.edu
authors.forename: Mary F
authors.initials: MF
authors.lastname: Kritzer
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000254:growth & development* / Q000378:metabolism*; D047629:Estrogen Receptor beta / Q000378:metabolism*; D004967:Estrogens / Q000378:metabolism*; D005260:Female; D007150:Immunohistochemistry; D008297:Male; D009415:Nerve Net / Q000254:growth & development / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012737:Sex Factors; D014018:Tissue Distribution
chemical_list: D047629:Estrogen Receptor beta; D004967:Estrogens