title: Cytoarchitectural characteristics of hippocampal CA1 pyramidal neurons of rats, four months after global cerebral ischemia and progesterone treatment.
abstract: OBJECTIVE
  To analyze the cytoarchitectural characteristics of the remaining pyramidal neurons in the hippocampal CA1 subfield of rats, four months after global cerebral ischemia (GCI) and progesterone treatment.
  
  
  METHODS
  Dendritic arborization, and density and shape of the dendritic spines of CA1 pyramidal neurons in brains of intact rats, or rats submitted 120 days earlier to GCI and treatment with progesterone (8 mg/kg) or its vehicle, at 15 min, and 2, 6, 24, 48, and 72 h after the onset of reperfusion, were analyzed in samples processed by a modified Golgi method.
  
  
  RESULTS
  Few impregnated CA1 pyramidal neurons were identified in the ischemic vehicle-treated rats, with a short apical dendrite devoid of bifurcations and dendritic spines. In contrast, the remaining CA1 pyramidal neurons sampled from ischemic progesterone-treated rats showed sinuously branched dendrites with similar number of bifurcations and whole density of spines, and higher proportional density of mushroom spines than those in the intact group.
  
  
  CONCLUSIONS
  These cytoarchitectural characteristics may underlie the long-term preservation of place learning and memory functions seen after ischemia and progesterone neuroprotective treatment, possibly compensating for the severe reduction in neuronal population.
authors.affiliation: Unidad de Investigación Médica en Farmacología, UMAE Hospital de Especialidades, Centro Médico Nacional Siglo XXI, IMSS, México, D. F. Mexico. gmorali@hotmail.com
authors.forename: Gabriela
authors.initials: G
authors.lastname: Moralí
authors.forename: Pedro
authors.initials: P
authors.lastname: Montes
authors.forename: Ignacio
authors.initials: I
authors.lastname: González-Burgos
authors.forename: Dulce A
authors.initials: DA
authors.lastname: Velázquez-Zamora
authors.forename: Miguel
authors.initials: M
authors.lastname: Cervantes
mesh_terms: D000818:Animals; D002545:Brain Ischemia / Q000188:drug therapy* / Q000473:pathology*; D056547:CA1 Region, Hippocampal / Q000473:pathology*; D004195:Disease Models, Animal; D011374:Progesterone / Q000627:therapeutic use*; D011372:Progestins / Q000627:therapeutic use*; D017966:Pyramidal Cells / Q000187:drug effects* / Q000648:ultrastructure; D051381:Rats; D016622:Silver Staining / Q000379:methods
chemical_list: D011372:Progestins; D011374:Progesterone