title: Thyroid hormones are essential to preserve non-proliferative cells of adult neurogenesis of the dentate gyrus.
abstract: Thyroid hormones (THs) regulate adult hippocampal neurogenesis, a process that involves both cell populations that dynamically switch between pools of proliferative and quiescent cells, and cells that definitely leave the cell cycle to maturate into granular neurons. This investigation was carried out to determine the role of THs on the mitotic activity of specific proliferative cell populations and the preservation of non-proliferative cells participating in the neurogenic process of the dentate gyrus (DG) of the hippocampus. Hypothyroidism was induced in male adult Wistar rats with methimazole for 28days. We quantified the total number of proliferative cells (BrdU+), proliferative type 1 (BrdU+/GFAP+), and 2b and 3 (BrdU+/DCX+) cells. Early non-proliferative cells (BrdU-/DCX+ cells lacking dendritic process), postmitotic neuroblasts (Tuj 1+ cells lacking dendritic process), and immature granular neurons (IGN; DCX+ or Tuj 1+ and the presence of dendritic processes into granular or molecular layer) were also included. The evidence showed that the proliferation of Type 1, 2b and 3 cells is not modified by hypothyroidism. In contrast, hypothyroidism reduced the number of early non-proliferative cells and also leads to a decrement in the number of IGN. Our results show that proliferative cells of the DG are not sensitive to thyroid perturbations. However, THs are essential to preserve cell populations that leave the cell cycle in the DG of the hippocampus.
authors: Departamento de Fisiología "Mauricio Russek", Instituto Politécnico Nacional, ENCB, Prol. Carpio y Plan de Ayala s/n, 11340 Mexico City, Mexico; Laboratorio de Neurociencias, Instituto Nacional de Pediatría, Insurgentes Sur # 3700, 04530 Mexico City, Mexico. Electronic address: karlasanchezhuerta@hotmail.com.
authors: K
authors: K
authors: Sánchez-Huerta
authors: Departamento de Fisiología "Mauricio Russek", Instituto Politécnico Nacional, ENCB, Prol. Carpio y Plan de Ayala s/n, 11340 Mexico City, Mexico. Electronic address: kiara_1515@hotmail.com.
authors: Y
authors: Y
authors: García-Martínez
authors: Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV), Av. IPN # 2508, 07360 Mexico City, Mexico. Electronic address: pvergara@fisio.cinvestav.mx.
authors: P
authors: P
authors: Vergara
authors: Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV), Av. IPN # 2508, 07360 Mexico City, Mexico. Electronic address: jsegovia@fisio.cinvestav.mx.
authors: J
authors: J
authors: Segovia
authors: Departamento de Fisiología "Mauricio Russek", Instituto Politécnico Nacional, ENCB, Prol. Carpio y Plan de Ayala s/n, 11340 Mexico City, Mexico. Electronic address: Jpachecor@ipn.mx.
authors: J
authors: J
authors: Pacheco-Rosado
mesh_terms: D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics / Q000378:metabolism; D049109:Cell Proliferation; D018891:Dentate Gyrus / Q000166:cytology* / Q000378:metabolism; D000089662:Doublecortin Protein; D008297:Male; D055495:Neurogenesis; D009474:Neurons / Q000166:cytology* / Q000378:metabolism / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D013963:Thyroid Hormones / Q000097:blood / Q000378:metabolism*
chemical_list: D019208:Brain-Derived Neurotrophic Factor; C000714848:Dcx protein, rat; D000089662:Doublecortin Protein; D013963:Thyroid Hormones
keywords: Adult neurogenesis; Dentate gyrus; Hippocampus; Hypothyroidism; Thyroid hormones; Type 1 cells; Type 2b cells; Type 3 cells