title: Effects of rivastigmine and memantine alone and in combination on learning and memory in rats with scopolamine-induced amnesia.
abstract: BACKGROUND
  Cholinesterase inhibitors and glutamate blockers are commonly used for the treatment of cognitive impairment in Alzheimer's disease. The aim was to evaluate the effects of rivastigmine and memantine alone or in combination in rats with scopolamine-impaired memory.
  
  
  METHODS
  5 groups of rats were used: control, scopolamine (model), model with rivastigmine, model with memantine, and model with both drugs. Active avoidance test was performed and the number of conditioned responses, unconditioned responses and intertrial crossing were recorded. Passive avoidance tests step-through with criteria latency of reaction 180 s in the light chamber and step-down with criteria latency of reaction 60 s on the platform were done.
  
  
  RESULTS
  Control rats learned the task and kept it on memory tests. Scopolamine treated rats failed to perform it. The rivastigmine, memantine and its combination groups showed increased CRs during learning and memory retention tests. In both passive avoidance tests an increased latency of reaction was observed in the drug treated groups.
  
  
  CONCLUSIONS
  The combination of both drugs rivastigmine and memantine is more effective than the use of the single drug in cognitive impaired rats. Cholinesterase inhibitors and NMDA blockers may be combined in the treatment of different kind of dementias.
authors.affiliation: College of William and Mary, Williamsburg, Virginia 23187, USA.
authors.forename: Peter Georgiev
authors.initials: PG
authors.lastname: Yanev
authors.affiliation: Department of Pharmacology and Clinical Pharmacology, Faculty of Medicine, Medical University, Plovdiv 4002, Bulgaria.
authors.forename: Darinka Slavcheva
authors.initials: DS
authors.lastname: Dimitrova
authors.affiliation: Department of Pharmacology, Medical Faculty, Medical University, 15A V. Aprilov str, Plovdiv 4002, Bulgaria, Tel: +359 32 602417; +359 882512960.
authors.forename: Damianka Peteva
authors.initials: DP
authors.lastname: Getova-Spassova
keywords: drug combination; memantine; rats; rivastigmine; scopolamine model