title: Cortical photothrombotic infarcts impair the recall of previously acquired memories but spare the formation of new ones.
abstract: OBJECTIVE
  Despite a high incidence of poststroke dementia, there is no specific treatment for this condition. Because the evaluation of poststroke cognitive deficits in animal models of stroke is exceedingly challenging, the preclinical evaluation of candidate drugs is limited. We aimed to explore the impact of small cortical photothrombotic strokes on poststroke cognition, thereby assessing the suitability of this experimental stroke model for the investigation of cognitive impairment after stroke.
  
  
  METHODS
  Photothrombotic cortical infarcts were induced in 19 adult male Wistar rats. Nineteen sham-operated animals served as controls. Using the Morris water maze, we analyzed the impact of photothrombotic stroke on both the acquisition of new memories and the recall of previously acquired memories. The cylinder test, the adhesive tape removal test, and the rotarod test were performed to investigate sensorimotor deficits.
  
  
  RESULTS
  Photothrombotic stroke significantly impaired the recall of previously acquired memories (P<0.05), whereas the acquisition of new memories remained largely intact. The analysis of the animals' swimming speed in the water maze and the rotarod test showed no confounding motor impairments after photothrombotic stroke. The adhesive tape removal test and the cylinder test revealed mild sensorimotor deficits in lesioned animals (P<0.05).
  
  
  CONCLUSIONS
  Photothrombotic cortical infarcts impair the recall of memories acquired before stroke, whereas the formation of new memories remains unimpaired. The observed deficits in the water maze are not confounded by disturbed motor functions. Overall, experimental photothrombotic strokes are well suited for the investigation of specific cognitive impairments after stroke.
authors.affiliation: From the Department of Neurology, University of Münster, Münster, Germany (K.D., A.S., J.-K.S., M.S., J.M.); and Department of Neurology, EvKB-Bethel, Bielefeld, Germany (W.-R.S.).
authors.forename: Kai
authors.initials: K
authors.lastname: Diederich
authors.forename: Antje
authors.initials: A
authors.lastname: Schmidt
authors.forename: Jan-Kolja
authors.initials: JK
authors.lastname: Strecker
authors.forename: Wolf-Rüdiger
authors.initials: WR
authors.lastname: Schäbitz
authors.forename: Matthias
authors.initials: M
authors.lastname: Schilling
authors.forename: Jens
authors.initials: J
authors.lastname: Minnerup
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001921:Brain / Q000473:pathology; D020766:Intracranial Embolism / Q000473:pathology / Q000523:psychology*; D008297:Male; D018782:Maze Learning / Q000502:physiology; D057567:Memory, Long-Term / Q000502:physiology; D011939:Mental Recall / Q000502:physiology; D009068:Movement / Q000502:physiology; D004856:Postural Balance / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D012677:Sensation / Q000502:physiology; D020521:Stroke / Q000473:pathology / Q000523:psychology*; D013550:Swimming / Q000502:physiology
keywords: animal model; brain ischemia; mild cognitive impairment; stroke