Figure 4.

Orexin^−/− mice that express Cre in GABA neurons (orexin^−/−,VGAT-Cre mice) exhibit typical cataplexy. A, In orexin^−/− mice, cataplexy is characterized by the abrupt loss of skeletal muscle tone during wakefulness and a theta-rich EEG. B, Magnification of boxed area in A. Orexin^−/−,VGAT-Cre mice express cataplexy electrophysiologically indistinguishable from that seen in conventional orexin^−/− mice as measured by masseter EMG (C), neck EMG (D), and EEG (E). F-H, There were no significant differences in the time spent in, number of episodes of, or average duration of cataplexy attacks in the first 3 h of behavioral recording of orexin^−/−,VGAT-Cre mice compared with orexin^−/− mice. A.U., Arbitrary units.