Neurogenesis in the subependymal layer of the adult rat: a role for neuroactive derivatives of progesterone.
The subependymal layer (SEL) of the adult mammalian brain provides a continuous supply of newborn cells that migrate to the olfactory bulb (OB) where they differentiate into interneurons. These newly generated cells migrate tangentially to the OB within a dense meshwork of astrocytic cells, organized to form tangentially oriented channels (glial tubes). The central nervous system is able to synthesize a variety of steroids. Among these, we analyzed the effects of progesterone (P) and its neuroactive metabolites dihydroprogesterone (DHP) and tetrahydroprogesterone (THP), administered by intraventricular injection, on the SEL of the adult rat. We found that THP and DHP, but not their precursor P, modify glial tubes organization and decrease immunoreactivity for glial associated proteins in SEL astrocytes. Moreover P metabolites reduce the proliferative activity within the SEL.
Giachino
Claudio
C
Department of Animal and Human Biology, University of Turin, Via Accademia Albertina 13, 10123 Turin, Italy. giachino@unito.it
Galbiati
Mariarita
M
Fasolo
Aldo
A
Peretto
Paolo
P
Melcangi
Roberto
R
D004092:20-alpha-Dihydroprogesterone / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D004805:Ependyma / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D009474:Neurons / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D009830:Olfactory Bulb / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D011374:Progesterone / Q000378:metabolism / Q000494:pharmacology*; D016548:Prosencephalon / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D051381:Rats
D004092:20-alpha-Dihydroprogesterone; D011374:Progesterone