Transcriptional regulation of PSA-NCAM mediated neuron-glial plasticity in the adult hypothalamus

Gonadotropin rclcasiag honnouc (GnRH)-sccrcting acurous ill inanunal's project principally to the niedian ouiumccarcuatc (ME-ARC) regiou wlicic they iuakc coutact with basal laruina aud open into the pericapillary space ofthc prunary hypophyscalporlolplexits. III theprcscutstudy we report the cxpressiou ofpolysialylatedforni ofacural ccll adhcsion atolecule (PSA-NCAM) oil the cell bodies of GuRH-scoviag ucurous and oil glial cells ill the nic(lial prcoptic arca (aWGIA) of the hypothalaunis ill both the procstrous aud dicstrous phascs of cycliag rats, using dual ill7ll7lil7Ollistojliiot-csceiit stabling. Regulatiou oJ_PSA-NCAM occurs iia regulation of PSA biosyathesis by thepolysialyltransfcrasc cnzyuie (PST-i). Therc/ore, we studied the expression of PST iaRNA aud GaRH ill GnRH-rcleasiug cell bodies by co"ibiaing fluoresceul III situ hylIriclizatioll Ivith ill I Ill In 7011 istafluorescei ice, and eXPITSSiOu Of PST oiRNA ill the aiPOA usiug i7orthcru blotting. VVc observed dynainic upr(gulation of PSA-NCAM oil GnRH cell bodies ill the proestrous phase, accoulpanicd by enhanced cxpressiou of PST-i iaRNA. The prescat results indicate that PSA-NCAM has a peraiissh,e role ill the structural rciaodeling ofGuRH ucurons. Enhaticcd cxprcssiou of ruRNA cucoding PST-i ill the proestrous phase iudicatcs that the biosyllthesis of PSA told, thus, PSA-NCAM is regulated at the transcriptional let,el.