Improvements of the Stroke Model Guidelines Animal body weight and long-term functional concerns

Author(s): Thomas Freret and Valentine Bouet

Despite extensive research efforts in the field of cerebral ischemia, numerous disappointments came out. Indeed, even if experimental studies showed up a huge number of promising drugs, most of them unfortunately failed to be efficient in clinical trials. Based on these reports, factors that play a significant role in causing outcome variation were identified and recently reviewed in the Rodent Stroke Model Guidelines for Preclinical Studies. Herein, we provide improvements to this first edition as regards to the functional evaluation section, especially regarding long-term evaluation. Indeed, as in clinical practice (Rothrock et al 1995), animals display a certain degree of spontaneous recovery after stroke (Hunter et al 1998; Roof et al 2001; Zausinger et al 2000; Zhang et al 2000). Typically, the neurological impairment, assessed by basic items, usually disappears during the initial week following stroke in rodents (Bederson et al 1986). As a contrary, more demanding sensorimotor and cognitive tasks underline other deficits, usually long-lasting. Unfortunately, studies addressing such behavioral impairments are less abundant. Therefore, because the characterization of long-term functional recovery is critical for evaluating the efficacy of potential therapeutic agents in experimental stroke, behavioral tests that proved to be sensitive enough to detect long-term deficits are reported here. Overall, since the ultimate goal of any stroke therapy is the restoration of normal functions, an objective appraisal of the behavioral deficits should be done.