Effect of dexmedetomidine (Dex) on wakefulness score. Data are shown as means±S.E.M. and down arrows indicate administration of dexmedetomidine or vehicle. A. Townes sickle mice had significantly lower wakefulness scores, i.e., were more sedated, both, at 30 and 60 min after dexmedetomidine (10, 25 and 50 µg/kg combined) compared to vehicle injections (both, P<0.001). B. Townes control mice had significantly lower wakefulness scores i.e., were more sedated, both, at 30 and 60 min after dexmedetomidine (10, 25 and 50 µg/kg combined) compared with vehicle (both P<0.001).