title: Spatial and Working Memory Is Linked to Spine Density and Mushroom Spines.
abstract: BACKGROUND
  Changes in synaptic structure and efficacy including dendritic spine number and morphology have been shown to underlie neuronal activity and size. Moreover, the shapes of individual dendritic spines were proposed to correlate with their capacity for structural change. Spine numbers and morphology were reported to parallel memory formation in the rat using a water maze but, so far, there is no information on spine counts or shape in the radial arm maze (RAM), a frequently used paradigm for the evaluation of complex memory formation in the rodent.
  
  
  METHODS
  24 male Sprague-Dawley rats were divided into three groups, 8 were trained, 8 remained untrained in the RAM and 8 rats served as cage controls. Dendritic spine numbers and individual spine forms were counted in CA1, CA3 areas and dentate gyrus of hippocampus using a DIL dye method with subsequent quantification by the Neuronstudio software and the image J program.
  
  
  RESULTS
  Working memory errors (WME) and latency in the RAM were decreased along the training period indicating that animals performed the task. Total spine density was significantly increased following training in the RAM as compared to untrained rats and cage controls. The number of mushroom spines was significantly increased in the trained as compared to untrained and cage controls. Negative significant correlations between spine density and WME were observed in CA1 basal dendrites and in CA3 apical and basal dendrites. In addition, there was a significant negative correlation between spine density and latency in CA3 basal dendrites.
  
  
  CONCLUSIONS
  The study shows that spine numbers are significantly increased in the trained group, an observation that may suggest the use of this method representing a morphological parameter for memory formation studies in the RAM. Herein, correlations between WME and latency in the RAM and spine density revealed a link between spine numbers and performance in the RAM.
authors.affiliation: Department of Pediatrics, Faculty of Medicine, Assuit University, Assuit, Egypt; Department of Pharmaceutical Chemistry, University of Vienna, 1090 Vienna, Austria.
authors.forename: Rasha Refaat
authors.initials: RR
authors.lastname: Mahmmoud
authors.affiliation: Department of Pharmaceutical Chemistry, University of Vienna, 1090 Vienna, Austria.
authors.forename: Sunetra
authors.initials: S
authors.lastname: Sase
authors.affiliation: Department of Pharmaceutical Chemistry, University of Vienna, 1090 Vienna, Austria.
authors.forename: Yogesh D
authors.initials: YD
authors.lastname: Aher
authors.affiliation: Department of Pharmaceutical Chemistry, University of Vienna, 1090 Vienna, Austria.
authors.forename: Ajinkya
authors.initials: A
authors.lastname: Sase
authors.affiliation: CF Imaging, Medical University of Vienna, 1090 Vienna, Austria.
authors.forename: Marion
authors.initials: M
authors.lastname: Gröger
authors.affiliation: Department of Pediatrics, Faculty of Medicine, Assuit University, Assuit, Egypt.
authors.forename: Maher
authors.initials: M
authors.lastname: Mokhtar
authors.affiliation: Core Unit of Biomedical Research, Division of Laboratory Animal Science and Genetics, Medical University of Vienna, Brauhausgasse 34, A-2325 Himberg, Austria.
authors.forename: Harald
authors.initials: H
authors.lastname: Höger
authors.affiliation: Department of Pharmaceutical Chemistry, University of Vienna, 1090 Vienna, Austria.
authors.forename: Gert
authors.initials: G
authors.lastname: Lubec
mesh_terms: D000818:Animals; D056547:CA1 Region, Hippocampal; D056654:CA3 Region, Hippocampal; D003712:Dendrites; D018891:Dentate Gyrus; D008297:Male; D018782:Maze Learning; D008570:Memory, Short-Term; D009474:Neurons / Q000166:cytology* / Q000502:physiology*; D011597:Psychomotor Performance; D017966:Pyramidal Cells / Q000166:cytology / Q000502:physiology; D051381:Rats