Post-acute delivery of α5-GABAA antagonist, S 44819, improves functional recovery in juvenile rats following stroke.

Hypo-excitability was reported in the peri-infarct tissue following stroke, an effect counteracted by a blockage of α5-GABAA receptors in adult rodents. Our present study aims to evaluate the effect of a selective α5-GABAA receptor antagonist, S 44819, in stroke in juvenile animals. We have set up and characterized an original model of transient ischemic stroke in 28 day-old Sprague-Dawley rats (45-min occlusion of the middle cerebral artery by intraluminal suture). In this model, S 44819 (1, 3 and 10 mg/kg, b.i.d) was orally administered from day 3 to day 16 after stroke onset. Sensorimotor recovery was assessed on day 1, day 9 and day 16 after stroke onset. Results show that rats treated with S 44819 at the doses of 3 and 10 mg/kg displayed a significant improvement of the neurological deficits (neuroscore) on day 9 and day 16, when compared with animals treated with vehicle. Grip-test data analysis reveals that rats treated with S 44819 at the dose of 3 mg/kg displayed a better recovery on day 9 and day 16. These results are in agreement with those previously observed in adult rats, demonstrating that targeting α5-GABAA receptors improves neurological recovery after stroke in juvenile rats.