Table 1.

Changes in sleep parameters following 4 h of sleep deprivation (8 a.m.–12 p.m.). Mean values and standard error (in parenthesis) for each age group are displayed. The deficit in NREM or REM sleep is the difference in minutes between the amount of each sleep phase during the recovery phase (the 20 h of recovery that follow 4 h of sleep deprivation), minus the amount during the 24 h baseline. During the first 20 h following sleep deprivation mice never recovered all the sleep that they lost during sleep deprivation, resulting in a negative value (deficit). The change in REM episode length is the difference in REM episode length for each mouse, as above calculated by subtracting the 20 h mean value during recovery minus the 24 h amount during baseline. The change in brief arousals is the difference in the number of short wake periods (<16 s) per minute of sleep during the first 4 h of recovery sleep after sleep deprivation, minus the number during the first 4 h of baseline sleep. Sleep during the deprivation is the total amount of sleep achieved during the 4 h of sleep deprivation. Sleep attempts during the deprivation is the total number of sleep attempts during the 4 h of sleep deprivation.

Age Group	P26–29	P34–36	P41–44	P50–56	Adults
NREM Deficit (min)	−38.13 (11.11)	−44.60 (13.96)	−43.00 (15.77)	−59.36 (10.66)	−66.91 (11.09)
REM Deficit (min)	−11.68 (3.04)	−8.32 (2.56)	−12.75 (3.80)	−12.58 (3.26)	−8.72 (3.68)
Change in REM episode length (min)	0.077 (0.059)	0.097 (0.044)	0.056 (0.068)	0.23 (0.081)	0.29 (0.069)
Change in Brief Arousals (number per min sleep 1st 4 h)	−0.0043 (0.0014)	−0.0046 (0.0023)	−0.0017 (0.0031)	−0.0020 (0.0021)	−0.0054 (0.0018)
Sleep during deprivation (min)	1.46 (0.16)	0.64 (0.26)	0.70 (0.29)	0.85 (0.34)	0.20 (0.16)
Sleep attempts (number during deprivation)	21.77 (2.33)	7.13 (3.78)	9.13 (3.34)	6.78 (1.76)	2.00 (1.57)