What is narcolepsy?
An unusual disorder in which the person is afflicted by frequent, intense attacks of sleep that last 5–30 minutes and can occur at any time during usual waking hours, every 90 minutes
What is cataplexy?
A sudden loss of muscle tone, leading to collapse of the body without loss of consciousness
What do narcoleptic dogs have a mutant gene for?
The hypocretin receptor
What does hypocretin prevent?
It prevents the transition from wakefulness directly into REM sleep
What happens when you interfere with hypocretin signaling
It leads to narcolepsy-related symptoms
What is orexin
A neuroleptics produced in the hypothalamus that is involved in switching between sleep states in narcolepsy and control of appetite; aka hypocretin
Where does Orexin neurons in the hypothalamus project to other sleep system centers?
- The basal
- Forebrain
- The reticular formation,
- Subcoeruleus
What does the orexin switch in the hypothalamus determine?
Wakefulness, non-REM sleep, or REM sleep
What do axons in the tuberomamillary nucleus induce?
SWS
How much percentage of orexin neurons have people with narcolepsy lost?
90%
What is sleep paralysis?
The temporary inability to move or talk either just before dropping off to sleep or, more often, just after waking; never last more than a few minutes
The pontine center
Hypothesis that sleep paralysis results when the pontine center continues to impose paralysis for a short while after a person awakes from a rem episode
Sleep disorders in children
Night terrors and sleep enuresis (bed-wetting)
Somnambulism (sleepwalking); occurs during stage 3 SWS; can persist into adulthood
What is REM Behavior Disorder?
organized behavior—such as fighting an imaginary foe, eating a meal, or acting like a wild animal—by a person who appears to be asleep
Characteristics of REM Behavior Disorder
- Begins after the age of 50
- More common in Men than Women
- This may be followed by early symptoms of Parkinson’s disease and dementia
- Suggests the widespread damage of these diseases begins in the brainstem region that imposes muscle atonia
What is sleep-onset insomnia?
- Difficulty in falling asleep
- can be caused by situational factors, such as shift work or jet lag
What is sleep-maintenance insomnia?
- Difficulty in staying asleep
- May be caused by drugs or neurological and psychiatric factors.
- Especially evident in respiratory disorders
Commonalities of Insomnia
- more commonly reported by older people, females, and users of drugs like tobacco, caffeine, and alcohol
- prevalence ranges from 10% to 40% of the adult population
What is sleep apnea?
Breathing may stop or slow down when muscles in the chest and diaphragm relax too much or from changes in the pacemaker respiratory neurons in the brainstem
Characteristics of sleep apnea
- Common in obese people
- Frequently accompanied by loud, interrupted snoring
What is sleep state misperception?
When people report they haven’t slept even when EEG indicates that they have
What is Sudden Infant Death Syndrome?
- The sudden, unexpected death of an apparently healthy infant who stops breathing, usually during sleep
- Arises from sleep apnea due to immature respiratory pacemaker systems or arousal mechanisms
- Putting babies to sleep on their backs has cut the incidence of SIDS almost in half.
What do sleeping pills bind to?
GABA receptors throughout the brain
What do sleeping pills do?
*Produce marked changes in sleep patterns that persist for days after use
* Become ineffective over time
* Can lead to daytime drowsiness and memory gaps
* Behavioral methods support healthy sleep; sleeping pills do not
