Hypocretin: Hypocretin is an important neurotransmitter. It stimulates the brain's arousal centers, maintaining wakefulness. Without it, sleep onset is sudden and uncontrollable.
REM Sleep: It is so called because of the Rapid Eye Movements that occur during this phase of sleep. Besides the eye movements there is heightened brian activity because the brain is actively dreaming at this stage and there is loss of muscle tone to prevent us from acting out our dreams.
NREM Sleep: This is the Non Rapid Eye Movement sleep and has four stages. Stage I is light sleep and stage IV is deep sleep (delta sleep)
Paralysis: is the complete loss of muscle function for one or more muscle groups.
Serotonin (5-hydroxytryptamine or 5-HT): is a monoamine neurotransmitter. It is believed to play an important role in the regulation of mood, sleep, emesis (vomiting), sexuality and appetite.
Human leukocyte antigen system (HLA):is the general name of a group of genes in the human major histocompatibility complex (MHC) region on human chromosome 6
Autoimmunity: is the failure of an organism to recognize its own constituent parts as "self", which results in an immune response against its own cells and tissues, thereby resulting in destruction of it’s own tissues.
Cataplexy: short-lived intermittent muscle weakness.
Hypnogogic and hypnopompic
hallucinations: hallucinations while falling asleep or waking.
Sleep paralysis: paralysis while falling asleep or waking.