Norepinephrine is synthesized from dopamine by dopamine Î²-hydroxylase.[7] It is released from the adrenal medulla into the blood as a hormone, and is also a neurotransmitter in the central nervous system and sympathetic nervous system where it is released from noradrenergic neurons. The actions of norepinephrine are carried out via the binding
Insomnia symptoms may include: 1  Difficulty falling asleep at night. 2  Waking up during the night. 3  Waking up too early.  Not feeling well-rested after a night's 1  sleep. Daytime tiredness or sleepiness.  Irritability, depression or 1  anxiety. Difficulty paying attention, focusing on tasks or remembering.  Increased errors or accidents.
Some common sleep disorders include sleep apnea (stops in breathing during sleep), narcolepsy and hypersomnia (excessive sleepiness at inappropriate times), cataplexy (sudden and transient loss of muscle tone while awake), and sleeping sickness (disruption of sleep cycle due to infection). Sleep apnea, obstructive sleep apnea, obstruction of the airway during sleep, causing lack of sufficient deep sleep, often accompanied by snoring. 2  Other forms of sleep apnea are less common. 3  When air is blocked from entering into the lungs, the individual unconsciously gasps for air and sleep is disturbed.