Figure 3.

Evaluation of the effect of three doses of zolpidem (solid lines) or vehicle (dashed lines) on immobility-defined sleep determined using digital video analysis. Zolpidem was dosed i.p at A) 10 mg/kg, B) 5mg/kg and C) 1mg/kg at ZT14. Zolpidem dosed at 10 and 5 mg/kg resulted in a significant increase in the amount of immobility-defined sleep (to around 90%) compared to vehicle (F_1,10=22.2,P<0.001 at 10mg/kg and F_1,10=11.8, P<0.01 at 5mg/kg). In addition, there were significant changes in sleep duration over the time course studied with all doses tested (F_5,50=6.1, P<0.001 at 10mg/kg; F_5,50=11.7, P<0.001 at 5mg/kg; F_5,50 =7.7, P<0.001 at 1mg/kg). At 10mg/kg and 5mg/kg there was also a significant interaction, with differences in sleep over the time course being dependent upon the vehicle or zolpidem treatment (F_5,50=2.6, P<0.05 at 10mg/kg; F_5,50=3.1, P<0.05 at 5mg/kg). A dose of 1 mg/kg zolpidem did not produce a significant effect on sleep duration from the vehicle. The solid black arrows indicate the time of drug/vehicle administration. Data points represent mean vales ± SEM for 6 mice. Bar graphs depict the total duration of immobility-defined sleep in hourly intervals where * denotes P< 0.05 and ** denotes P<0.01. Note: A separate vehicle condition was used for each of the doses of zolpidem. In all cases sleep per 10min interval is shown and sensitivity was set at 95%.