How right is the righting reflex? The risk of false positives in neuroprotection studies using behavioral measures to certify forebrain ischemia.
The righting reflex (RR) as a behavioral index of incomplete ischemia during four-vessel occlusion (4VO) remains a common exclusion criterion. In the present study different drugs (aniracetam, ondansetron, and metyrapone) were administered to Wistar rats at a variety of doses prior to unanesthetized forebrain ischemia lasting 10 minutes forebrain ischemia in. Using the RR as an exclusion criterion, their effects on neuronal survival and functional recovery were investigated. Our observations revealed dose-related suppression of RR expression leading to a higher proportion of drug-treated rats categorized as having experienced successful ischemia compared to the vehicle-treated groups. If uncontrolled, this effect led to assessments of increased neuronal survival (in CA1 hippocampal subfield) or improved cognitive behavioral recovery in treated rats. These observations appeared to be related to failure in identifying rats subjected to incomplete forebrain ischemia producing minimal neuronal damage rather than protective effects associated to drug administration. These findings highlight the risk of falsely reporting treatment-related neuronal protection with the unanesthetized 4VO model in rodents.
Milot
Marc R
MR
University of Ottawa, School of Psychology, Behavioral Neuroscience Group, Canada.
Plamondon
Hélène
H
D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D008297:Male; D008569:Memory Disorders / Q000188:drug therapy / Q000209:etiology; D008797:Metyrapone / Q000627:therapeutic use; D018696:Neuroprotective Agents / Q000494:pharmacology* / Q000627:therapeutic use; D017294:Ondansetron / Q000627:therapeutic use; D016548:Prosencephalon / Q000187:drug effects / Q000473:pathology*; D011760:Pyrrolidinones / Q000627:therapeutic use; D051381:Rats; D017208:Rats, Wistar; D057897:Reflex, Righting / Q000187:drug effects* / Q000502:physiology; D015427:Reperfusion Injury / Q000150:complications / Q000175:diagnosis / Q000517:prevention & control
D018696:Neuroprotective Agents; D011760:Pyrrolidinones; D017294:Ondansetron; C036466:aniracetam; D008797:Metyrapone