REM sleep & Narcolepsy
SWS terrors are responsive to drugs that reduce SWS.
SWS terrors decrease with SWS decrease with age.
REM nightmares have storylines, SWS ones have image and poorer recall.
Sleep 1998;21(6):609-14.
NYKAMP K, ROSENTHAL L, FOLKERTS M, ROEHRS T, GUIDO P, ROTH T.
Emmanuel Mignot MD, Stanford Sleep Clinic:
Genetic and pathophysiological aspects of narcolepsy, a disorder of REM sleep
Narcolepsy is a neurological disorder characterized by:
Treated with
Monoamines are serotonin, epinephrin, dopamine.
Most effective treatment is with NE uptake inhibitors (remember NE is made by locus coeruleous).
Narcoleptics have too much Ach (remember Ach is produced by REM-ON cells in brainstem). These abnormalities, however, are unlikely to be the initial defect producing narcolepsy. .
Genetic studies in humans have isolated a specific Human Leukocyte Antigen (HLA) allele that strongly predispose to narcolepsy. Further isolated by using subjects from different racial groups. Black people are much more genetically diverse than Caucasian or Japanese.
HLA antigens are polymorphic across the population and determine how well different antigens are presented to the immune system. Specific HLA alleles are often linked to autoimmune diseases.
Research in narcolepsy is greatly facilitated by the existence of a unique animal model for the disorder, canine narcolepsy. The dogs were found by giving a talk about human narcolepsy to a group of veterinarians, among which was one who had a litter of narcoleptic dogs.
A linkage marker has been identified in canine narcolepsy and positional cloning efforts have isolate the gene involved: hypocretin.
Drugs that affect the immune system in dogs affect canine narcolepsy.
Naps
Eur J Appl Physiol 1998;78(2):93-8.
TAKAHASHI M, FUKUDA H, ARITO H.
National Institute of Industrial Health, Kawasaki, Japan
This study was designed to examine the effects of brief naps taken after lunch on alertness, performance, and autonomic balance. Three groups each comprising ten healthy subjects, who had slept normally at home the previous night, were randomly assigned to groups taking one of three 'lengths of nap (0, 15, and 45 min) after lunch. The P300, an event-related potential which is a neurophysiological correlate of cognitive function, subjective sleepiness (visual analogue scale), and electrocardiogram were measured before, 30 min after, and 3 h after the naps. Each measurement was followed by an English transcription task lasting 90 min. The P300 latency was significantly shorter after the 15- min than after the 45-min nap, or after no nap had been taken, while its amplitude was not affected by the length of nap. Subjective sleepiness was lower after both naps than after no nap. The task performance was significantly better during the second half of the last task session after the 15-min nap than after no nap. The high-frequency component of the R-R interval spectrum increased significantly during the 45-min nap, showing a temporary shift to a predominance of the parasympathetic nervous system. Mean total sleep times during the 15- and 45-min naps were 7.3 and 30.1 min, respectively. These results would indicate that the 15-min nap may serve to shorten the stimulus evaluation time, reducing subjective sleepiness, and slightly improving task performance. Our data demonstrated that in our subjects a brief nap after lunch was effective for enhancing subsequent alertness and performance after normal sleep the previous night.
J Neurophysiol 1998;80(5):2765-75.
SATO-SUZUKI I, KITA I, OGURI M, ARITA H.
When to wake up
Webb (1978): Spontaneous ending of sleep happens at various stages of sleep after continuous sleep in different subjects.
Taub (1983): Psychometric alertness significantly less in conjunction with ad libitum delayed morning sleep and for individuals whose awakenings occurred after 11:00.
Campbell (1985):
Barbato et al (1994): 48% REM awakenings for normal night sleep.