Wakefulness involves diffuse activation of cerebral cortex through Ascending Reticular Activating System (RAS), which connects midbrain and pons to cortex through the thalamus and hypothalamus. RAS is primarily composed of the pedunculopontine tegmentum (PPT) & laterodorsal tegmentum (LDT) of pons, locus coeruleus nucleus (LC) and dorsal raphe nucleus (RN) which involves all classic...