title: Effect of cholecystokinin on learning and memory, neuronal proliferation and apoptosis in the rat hippocampus.
abstract: BACKGROUND
  Cholecystokinin (CCK) has roles in learning and memory, but the cellular mechanism is poorly understood. This study investigated the effect of CCK on spatial learning and memory, neuronal proliferation and apoptosis in the hippocampus in rats.
  
  
  METHODS
  Experimental groups were control and CCK. The rats received CKK octapeptide sulfated (CCK-8S, 1.6 μg/kg, i.p.) for 14 days. Spatial learning and memory were tested by Morris water maze and finally immunohistochemical study was performed; neurogenesis by Ki-67 method and apoptosis by Terminal deoxynucleotidyl transferase mediated dUTP Nick End Labeling (TUNEL) assay in hippocampal dentate gyrus (DG).
  
  
  RESULTS
  Cholecystokinin increased Ki-67 positive cells and reduced TUNEL positive cells in the granular layer of hippocampal DG. CCK failed to have a significant effect on spatial learning and memory.
  
  
  CONCLUSIONS
  Results indicate neuroprotective and proliferative effects of CCK in the hippocampus; however, other factors are probably involved until the newly born neurons achieve necessary integrity for behavioral changes.
authors.affiliation: Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran ; Biosensor Research Center, Isfahan University of Medical Sciences, Isfahan, Iran ; Physiology Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Parham
authors.initials: P
authors.lastname: Reisi
authors.affiliation: Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Ali Reza
authors.initials: AR
authors.lastname: Ghaedamini
authors.affiliation: School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Golbidi
authors.affiliation: Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Moloud
authors.initials: M
authors.lastname: Shabrang
authors.affiliation: Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Zohreh
authors.initials: Z
authors.lastname: Arabpoor
authors.affiliation: Department of Anatomical Sciences, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Bahman
authors.initials: B
authors.lastname: Rashidi
keywords: Apoptosis; cholecystokinin; hippocampus; learning; memory; neurogenesis