title: A comparison of scopolamine and biperiden as a rodent model for cholinergic cognitive impairment.
abstract: BACKGROUND
  The nonselective muscarinic antagonist scopolamine hydrobromide (SCOP) is employed as the gold standard for inducing memory impairments in healthy humans and animals. However, its use remains controversial due to the wide spectrum of behavioral effects of this drug.
  
  
  OBJECTIVE
  The present study investigated whether biperiden (BIP), a muscarinic m1 receptor antagonist, is to be preferred over SCOP as a pharmacological model for cholinergic memory deficits in rats. This was done by comparing the effects of SCOP and BIP using a battery of operant tasks: fixed ratio (FR5) and progressive ratio (PR10) schedules of reinforcement, an attention paradigm and delayed nonmatching to position task.
  
  
  RESULTS
  SCOP induced diffuse behavioral disruption, which included sensorimotor responding (FR5, 0.3 and 1 mg/kg), food motivation (PR10, 1 mg/kg), attention (0.3 mg/kg, independent of stimulus duration), and short-term memory (delayed nonmatching to position (DNMTP), 0.1 and 0.3 mg/kg, delay-dependent but also impairment at the zero second delay). BIP induced relatively more selective deficits, as it slowed sensorimotor responding (FR5, 10 mg/kg) and disrupted short-term memory (DNMTP, 3 mg/kg, delay-dependent but no impairment at the zero second delay). BIP had no effect on food motivation (PR10) or attention.
  
  
  CONCLUSIONS
  Muscarinic m1 antagonists should be considered an interesting alternative for SCOP as a pharmacological model for cholinergic mnemonic deficits in animals.
authors.affiliation: Faculty of Psychology and Neuroscience, Department of Neuropsychology and Psychopharmacology, European Graduate School of Neuroscience (EURON), Maastricht University, Maastricht, The Netherlands. inge.klinkenberg@maastrichtuniversity.nl
authors.forename: Inge
authors.initials: I
authors.lastname: Klinkenberg
authors.forename: Arjan
authors.initials: A
authors.lastname: Blokland
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001712:Biperiden / Q000008:administration & dosage / Q000633:toxicity*; D003072:Cognition Disorders / Q000139:chemically induced* / Q000503:physiopathology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D008297:Male; D008568:Memory / Q000187:drug effects; D018727:Muscarinic Antagonists / Q000008:administration & dosage / Q000633:toxicity; D051381:Rats; D017208:Rats, Wistar; D043643:Receptor, Muscarinic M1 / Q000037:antagonists & inhibitors; D012055:Reinforcement Schedule; D012601:Scopolamine / Q000008:administration & dosage / Q000633:toxicity*; D013997:Time Factors
chemical_list: D018727:Muscarinic Antagonists; D043643:Receptor, Muscarinic M1; D001712:Biperiden; D012601:Scopolamine