I'm on an academic network, so I'm not sure if the PDF's paywalled...
From a cursory glance at the paper, this is what they had to say about how they kept the mice awake:
Mice were housed in a light/dark environment with lights on from 6:00 A.M. to 6:00 P.M. ... A previously validated, enriched, novel environment (Gompf et al., 2010) was used to promote spontaneous exploratory wakefulness. The short-term wakefulness (Sh Wake) period selected was 3 h during the lights-on period. With zeitgeber time 0 h (ZT0) referenced to the onset of the lights-on period, Sh Wake occurred at ZT8–ZT11, while extended sleep loss (Ext Wake) consisted
of 8 h of continuous wake time at ZT3–ZT11 with 16 h intervals in the home cages after the first and second days of 8 h wake time.
I'm on an academic network, so I'm not sure if the PDF's paywalled...
From a cursory glance at the paper, this is what they had to say about how they kept the mice awake:
Mice were housed in a light/dark environment with lights on from 6:00 A.M. to 6:00 P.M. ... A previously validated, enriched, novel environment (Gompf et al., 2010) was used to promote spontaneous exploratory wakefulness. The short-term wakefulness (Sh Wake) period selected was 3 h during the lights-on period. With zeitgeber time 0 h (ZT0) referenced to the onset of the lights-on period, Sh Wake occurred at ZT8–ZT11, while extended sleep loss (Ext Wake) consisted of 8 h of continuous wake time at ZT3–ZT11 with 16 h intervals in the home cages after the first and second days of 8 h wake time.