title: Effects of short-term hormonal replacement on learning and on basal forebrain ChAT and TrkA content in ovariectomized rats.
abstract: It has been proposed that sex steroid hormones improve performance in some cognitive tasks by regulating the basal forebrain cholinergic function. However, the molecular basis of such influence still remains unknown. Current study analyzed the performance of ovariectomized rats in an autoshaping learning task after a short-term treatment with 17β-estradiol (E2: 4 and 40μg/kg) and/or progesterone (P4: 4mg/kg). These results were correlated with basal forebrain choline acetyltransferase (ChAT) and TrkA protein content. The high dose of E2 enhanced both acquisition in the autoshaping task and the content of ChAT and TrkA. P4 treatment increased ChAT and TrkA content without affecting performance of rats in the autoshaping learning task. Interestingly, the continuous and simultaneous administration of E2 plus P4 did not significantly modify behavioral and biochemical evaluated parameters. These results address the influence of both E2 and P4 on cholinergic and TrkA activity and suggest that the effects of ovarian hormones on cognitive performance involve basal forebrain cholinergic neurons.
authors.affiliation: Escuela Superior de Medicina, Sección de Estudios de Posgrado e Investigación, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón s/n, D.F. C.P. 11340, Mexico. judaer@hotmail.com
authors.forename: Judith
authors.initials: J
authors.lastname: Espinosa-Raya
authors.forename: Noemí
authors.initials: N
authors.lastname: Plata-Cruz
authors.forename: Teresa
authors.initials: T
authors.lastname: Neri-Gómez
authors.forename: Ignacio
authors.initials: I
authors.lastname: Camacho-Arroyo
authors.forename: Ofir
authors.initials: O
authors.lastname: Picazo
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002795:Choline O-Acetyltransferase / Q000378:metabolism*; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D020249:Hormone Replacement Therapy; D007858:Learning / Q000187:drug effects*; D009043:Motor Activity / Q000187:drug effects; D009419:Nerve Tissue Proteins / Q000032:analysis / Q000096:biosynthesis; D010052:Ovariectomy; D011374:Progesterone / Q000494:pharmacology*; D016548:Prosencephalon / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020917:Receptor, trkA / Q000378:metabolism*
chemical_list: D009419:Nerve Tissue Proteins; D011374:Progesterone; D004958:Estradiol; D002795:Choline O-Acetyltransferase; D020917:Receptor, trkA