title: Tests used to assess the cognitive abilities of aged rats: their relation to each other and to hippocampal morphology and neurotrophin expression.
abstract: BACKGROUND
  Aged rodents have proven to be a useful tool in studying age-related cognitive decline, particularly with regard to hippocampal function. A number of maze tests have been developed to evaluate hippocampal function in aged rodents, including the eight-arm radial maze, Barnes circular platform maze and Morris water maze. To some extent, these mazes have been used interchangeably to evaluate aged animals. Few researchers, however, have examined how performance of individual, aged animals compares in these three mazes.
  
  
  OBJECTIVE
  The purpose of this study was to compare the performances in the three mazes and to examine how such performances are related to each other, to hippocampal morphology and to neurotrophin gene expression.
  
  
  METHODS
  We screened groups of young and old Fisher 344 x Brown Norway rats for general health and physical abilities, tested the animals in the three mazes and examined correlations among performances in the mazes and in screening tests. Hippocampal neuron density and expression of hippocampal neurotrophin mRNAs were also examined and compared with behavior in the three mazes.
  
  
  RESULTS
  Aged animals were found to be impaired in all three mazes and to have lower hippocampal neuron densities compared with young animals, with poor learning behavior significantly correlating with reduced hippocampal neuron density. Differences were observed between performance in the different mazes, but in general the Morris water maze and Barnes circular platform maze were found to give similar results.
authors: Neuroscience Program, Tulane University Medical School, New Orleans, LA 70112, USA.
authors: R N
authors: RN
authors: McLay
authors: S M
authors: SM
authors: Freeman
authors: R E
authors: RE
authors: Harlan
authors: A J
authors: AJ
authors: Kastin
authors: J E
authors: JE
authors: Zadina
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D002452:Cell Count; D003071:Cognition / Q000502:physiology*; D017931:DNA Primers; D018507:Gene Expression Regulation, Developmental; D006624:Hippocampus / Q000166:cytology / Q000254:growth & development / Q000502:physiology*; D018782:Maze Learning / Q000502:physiology; D009043:Motor Activity / Q000502:physiology; D009414:Nerve Growth Factors / Q000235:genetics*; D009474:Neurons / Q000737:chemistry / Q000166:cytology / Q000502:physiology; D004856:Postural Balance / Q000502:physiology; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D011916:Rats, Inbred F344
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D017931:DNA Primers; D009414:Nerve Growth Factors; D012333:RNA, Messenger