Answer to Question 1
Answer: Certain aspects of REM sleep (paralysis, dreaming) appear to intrude into the daytime hours in a person with narcolepsy. Sleep attack is an overwhelming urge to sleep for a few minutes. During cataplexy, a person has paralysis while conscious, whereas during sleep paralysis occurs just before or just after sleep. Hypnagogic hallucinations are dreams that occur during sleep paralysis. Sleep attacks can be treated using amphetamine-like stimulants, whereas antidepressant drugs (which act on serotonin and norepinephrine) are effective against other narcolepsy symptoms. Depressed persons show fragmented REM sleep, and antidepressant drugs suppress REM sleep.
Answer to Question 2
Answer: Cortical arousal refers to alertness and wakefulness and is indexed by cortical desynchrony. Acetylcholine is contained within two sets of neurons and released in the cortex to induce desynchrony. One pathway is from the pons to cortex, and the other is from the basal forebrain to cortex. Electrical stimulation of the pons induces cortical desynchrony and is accompanied by marked increases in acetylcholine levels. Serotonin-containing neurons are located within the raphe nuclei. Serotonin neurons may be most active during waking and are almost silent during REM sleep.