Ch. 8 Sleep
_________________ remains consistent & generates a rhythm slightly LONGER THAN 24 HRS when it has no external cue to guide it (e.g., cave dwelling).
Human circadian clock
damage to the Suprachiasmatic Nucleus (SCN) results in....
LESS consistent body rhythms that are no longer synchronized to daily light-dark cycles. (Circadian rhythms still occur but they are just not synchronized to the light/dark cycling.)
Medical treatment for Narcoleptic patients:
Narcoleptic patients can be substantially helped but NOT cured. Sleepiness is treated with AMPHETAMINE-like stimulants, while the symptoms of abnormal REM sleep intrusion are treated using ANTIDEPRESSANTS to enhance serotonin.
REM sleep is also associated with high-amplitude electrical potentials known as ___________________.
PGO waves
Normally, MOTOR CONTROL during REM sleep is PREVENTED because the ___________ sends messages to the spinal cord to inhibit motor pathways that control the large muscles
Pons
Among humans, those who get the most sleep have the highest percentage of _____________.
REM
paradoxical sleep =
REM sleep b/c EEG during REM sleep looks same as when awake
How many stages of sleep are there?
There are four stages of sleep plus rapid eye movement (REM) sleep (i.e., dream sleep). (When a person falls asleep, they progress through stages 1, 2, 3, & 4 in sequence and then back from stage 4 to 3 to 2, & then REM; each cycle lasts approx 90 min.)
Progression of sleep stages:
When a person falls asleep, they progress through stages 1, 2, 3, & 4 in sequence and then back from stage 4 to 3 to 2, & then REM; each cycle lasts approx 90 min.
REM is regulated by ____a_________ and _______b________. -drugs that stimulate ____a________ receptors quickly move people to REM. (REM is activated by these pathways) -_______b______ interrupts REM (REM is inhibited by these pathways)
a) acetylcholine (+) b) serotonin (-).
Sleepiness in narcoleptics is treated with _________a____________, while while the symptoms of abnormal REM sleep intrusion are treated using ____________________b___________________. Nevertheless, Narcoleptic patients can be substantially helped but not ______c_____
a) amphetamine-like stimulants b) antidepressants to enhance serotonin c) cured
when the eye of an air traveler perceives dawn or dusk many hours earlier or later than usual, the ______a_________ of the _________b_________ may trigger activities that the rest of the body is not ready for, & _______c______ occurs. -People who engage in shift work may take about 3 weeks or more to adjust; some fail to make a complete adjustment.
a) suprachiasmatic nucleus b) hypothalamus c) jet lag
The large majority of narcoleptic patients in the US are still _______a_______, & narcolepsy is most often diagnosed only after many years of _____b______.
a) undiagnosed b) struggle
Since the 1960s, it has been thought that narcolepsy symptoms are...
abnormal episodes of REM sleep inappropriately occurring during wakefulness
How long does each cycle of sleep last?
approx 90 min.
When sun rises, photoreceptors are... ALSO 3rd set of photoreceptors containing MELANOPSIN that responds to BLUE LIGHT that stimulate these photoreceptors and results in inhibition of pineal glands (pineal glands release melatonin, released 2-3 hrs before bed time)
are inhibited (rods and cones)
activity in REM is similar to when..
awake (very fast and low amplitude; REM people will report dreaming)
During REM sleep, _____________ is increased
awareness
sleep is is a state that the ___________ actively produces.
brain
Purpose of the _______________ is to keep our internal workings in phase with the outside world.
circadian rhythm
All animals produce endogenous _______________________ , internal mechanisms that operate on an approximately 24 hour cycle to affect sleep waking & other bodily functions (e.g., eating, drinking, body temperature, secretion of hormones, urination). Purpose of the _______________ is to keep our internal workings in phase with the outside world. -There are many health problems associated with disturbances of the human ___________________, such as: cognitive difficulties & increased risk of hypertension, diabetes, obesity, depression, heart attack, & stroke.
circadian rhythms
_____________________ is regulated by nuclei in brain that last about 24 hrs to purpose keep us in phase w/ outside world that so when we are awake we will have optimal physical functioning, ready to respond)
circadian rhythms
are many health problems associated with disturbances of the human circadian rhythm, such as:
cognitive difficulties & increased risk of hypertension, diabetes, obesity, depression, heart attack, & stroke.
another term for jet lag is ___________________
desynchronosis
Mismatch between actual time of day and actual biological rhythms= "_______________"
desynchronosis ((jet lag)
_______________ was used to discover that there are various stages of sleep. -Allows researchers to compare brain activity at different times during sleep. -(1930s) enabled scientists to measure brain function even when person is sleeping and associate diff. stages of sleep with diff. types of brain activity using POLYSOMONOGRAPHY study
electroencephalograph (EEG)
as we get more drowsy, amplitude of waves....
increase and slow down (activity moves from desynchronize activity to synchronized movement of left and right hemispheres as we drift further into sleep)
______________ refers to the disruption of the circadian rhythms due to crossing time zones, also called "desynchronosis". -a mismatch between the internal circadian clock vs. external time. -Characterized by sleepiness during the day, sleeplessness at night, impaired concentration, irritability, headaches, digestive problems, & disorientation.
jet lag
_________________ is Characterized by sleepiness during the day, sleeplessness at night, impaired concentration, irritability, headaches, digestive problems, & disorientation
jet lag (desynchronosis)
3rd set of photoreceptors containing ______________ that responds to BLUE LIGHT that stimulate these photoreceptors and results in inhibition of PINEAL GLANDS (pineal glands release melatonin, released 2-3 hrs before bed time)
melanopsin
RETINOHYPOTHALMIC PATH comes from a set of ganglion cells linked to special photoreceptor cells that have their own photopigment (_____________________) -these photoreceptors respond directly to light (blue) & do not require any input from the rods or cones.
melanopsin
Light resets the Suprachiasmatic Nucleus (SCN) via a small optic nerve branch (known as the ______________________________) directly from retina to SCN. ________________________ comes from a set of ganglion cells linked to special photoreceptor cells that have their own photopigment (MELANOPSIN). ----------these photoreceptors respond directly to light (blue) & do not require any input from the rods or cones.
retinohypothalamic path
Neurobiology of ____________. ______________ is a state that the brain actively produces. -Characterized by a moderate brain activity & response to stimuli.
sleep
what is purpose of circadian rhythm?
to keep our internal workings in phase with the outside world.
in ____________ state, patients are arousal (ex: can see heart rate increase in response to stimulus) but are not aware/responsive of what is going on around them (shows that awareness and arousal Don't have to go hand in hand)
vegetative
Easier to move ____________ and adjust circadian rhythm
west
Neurobiological Basis of Narcolepsy
-Normally, motor control during REM sleep is prevented because the Pons sends messages to the spinal cord to inhibit motor pathways that control the large muscles. -Since the 1960s, it has been thought that narcolepsy symptoms are abnormal episodes of REM sleep inappropriately occurring during wakefulness. -Evidence indicates that narcolepsy is due to a hypocretin peptide deficiency, possibly due to mutations of the hypocretin receptor genes or to an autoimmune attack. -Medical treatment: Narcoleptic patients can be substantially helped but not cured. Sleepiness is treated with amphetamine-like stimulants, while the symptoms of abnormal REM sleep intrusion are treated using antidepressants to enhance serotonin.
(Dreaming) During REM sleep:
-activity INCREASES in the pons, limbic system, parietal cortex, temporal cortex, primary visual cortex, motor cortex, & prefrontal cortex. -activity in the PONS triggers the onset of REM sleep. -REM is regulated by acetylcholine (+) & serotonin (-). -drugs that stimulate Ach receptors quickly move people to REM. -serotonin interrupts REM. Order REM-related activity is detected: first in the pons, then in the lateral geniculate of the thalamus, & then the occipital cortex. -20% of sleep time is spent in REM -Among humans, those who get the most sleep have the highest percentage of REM.
Narcolepsy is estimated to affect ____ in every ________ persons in US; comparable to incidence of Multiple Sclerosis.
1 in every 3000
The four main symptoms of narcolepsy include:
1) SLEEPINESS ATTACK: onset may be gradual or sudden. 2) CATAPLEXY: muscle weakness triggered by strong emotions. Typically, upon laughing, elation, surprise or anger, the person might fall down & become completely paralyzed for a few sec to several minutes. 3) SLEEP PARALYSIS: inability to move while asleep or waking up. 4) HYPNANOGIC HALLUCINATIONS: dreamlike auditory and/or visual hallucinations, which the person has difficulty distinguishing from reality.
the two major components of consciousness:
1) the level of consciousness (i.e., AROUSAL) 2) the content of consciousness (i.e., AWARENESS). (Don't have to go hand in hand ex: -in a coma, arousability and awareness are minimal -when conscious arousability and awareness are maximal -in vegetative state, patients are arousal (ex: can see heart rate increase in response to stimulus) but are not aware/responsive of what is going on around them -minimal consciousness, patients are aroused but have minimal awareness) -During REM sleep, awareness is increased)
Humans spend ___________ of their life asleep.
1/3
__________ % of sleep time is spent in REM
20%
_______________ is the main control center of the circadian rhythms of sleep & body temperature -regulates circadian rhythms, in an automatic and unlearned manner DAMAGE to this area of the hypothalamus results in LESS consistent body rhythms that are no longer synchronized to daily light-dark cycles. Circadian rhythms still occur but they are just not synchronized to the light/dark cycling. -______________________ does not generate circadian rhythms itself. Other CNS nuclei are responsible to do this.
Suprachiasmatic Nucleus (SCN)
How is REM-related activity detected?
first in the pons, then in the lateral geniculate of the thalamus, & then the occipital cortex.
Evidence indicates that narcolepsy is due to a _____________________________, possibly due to mutations of the hypocretin receptor genes or to an autoimmune attack
hypocretin peptide deficiency
___________ is in the visual pathway (here visual info in photoreceptors synapses)
lateral geniculate nucleus
ability to control dream content and you are aware that you are dreaming
lucid dreaming
when conscious arousability and awareness are ___________
maximal
The pineal gland secretes ________________, a hormone that increases sleepiness (released 2-3 hrs before bed time resulting in sleepiness) -secretion usually begins 2 to 3 hours before bedtime. -feeds back to reset the biological clock through its effects on receptors in the Suprachiasmatic Nucleus SCN. -_________________ taken in the afternoon can phase-advance the internal clock (circadian rhythm & can be used as a sleep aid to counter jet lag when moving eastward.
melatonin
_____________ feeds back to reset the biological clock through its effects on receptors in the Suprachiasmatic Nucleus SCN
melatonin
__________________ taken in the afternoon can phase-advance the internal clock (circadian rhythm & can be used as a sleep aid to counter jet lag when moving eastward. --------Easier to move west and adjust circadian rhythm
melatonin
in a coma, arousability and awareness are ________
minimal
Normally, ________________ during REM sleep is PREVENTED because the PONS sends messages to the spinal cord to inhibit motor pathways that control the large muscles.
motor control
___________________ is a sleep disorder & the 2nd leading cause of excessive daytime sleepiness diagnosed by sleep centers [obstructive sleep apnea is #1]. -It is estimated to affect 1 in every 3000 persons in US; comparable to incidence of Multiple Sclerosis. -The large majority of narcoleptic patients in the US are still undiagnosed, & narcolepsy is most often diagnosed only after many years of struggle. The four main symptoms of _______________include: 1) SLEEPINESS ATTACK: onset may be gradual or sudden. 2) CATAPLEXY: muscle weakness triggered by strong emotions. Typically, upon laughing, elation, surprise or anger, the person might fall down & become completely paralyzed for a few sec to several minutes. 3) SLEEP PARALYSIS: inability to move while asleep or waking up. 4) HYPNANOGIC HALLUCINATIONS: dreamlike auditory and/or visual hallucinations, which the person has difficulty distinguishing from reality. --Evidence indicates that narcolepsy is due to a HYPOCRETIN PEPTIDE DEFICIENCY, possibly due to mutations of the hypocretin receptor genes or to an autoimmune attack Medical treatment: Narcoleptic patients can be substantially helped but NOT cured. Sleepiness is treated with AMPHETAMINE-like stimulants, while the symptoms of abnormal REM sleep intrusion are treated using ANTIDEPRESSANTS to enhance serotonin.
narcolepsy
The _________________ is an endocrine gland located posterior to the thalamus. The SCN controls it's function. -secretes MELATONIN, a hormone that increases sleepiness.
pineal gland
_______________ releases MELATONIN, released 2-3 hrs before bed time resulting in sleepiness
pineal gland
_______________ uses a combination of EEG & eye- & limb-movement, & breathing recordings.
polysomnography sleep study
activity in the ____________ triggers the onset of REM sleep
pons
Human circadian clock remains consistent & generates a rhythm slightly ___________________ -Most people can adjust to 23- or 25- hour days but not to a 22- or 28-hour day. Resetting the circadian rhythms is sometimes necessary (e.g., weekends, yeah!).
slightly longer than 24 hrs when it has no external cue to guide it (e.g., cave dwelling).
Above optic chasm is the _____________________ (SCN) which DOES NOT cause biological rhythms to occur.. Just SYNCHRONIZES biological rhythms with rising and setting sun (________________ does not generate circadian rhythms itself. Other CNS nuclei are responsible to do this.)
suprachiasmatic nucleus
To help the body tell the time of day, fibers in the optic nerve of the eye transmit perceptions of light & darkness to a timekeeping center (_____________________) within the HYPOTHALAMUS. -Thus, when the eye of an air traveler perceives dawn or dusk many hours earlier or later than usual, this region of the hypothalamus may trigger activities that the rest of the body is not ready for, & jet lag occurs. -People who engage in shift work may take about 3 weeks or more to adjust; some fail to make a complete adjustment.
suprachiasmatic nucleus
the suprachiasmatic nucleus (SCN) DOES NOT cause biological rhythms to occur. It Just __________________ biological rhythms with rising and setting sun (SCN in hypothalamus that synchronizes rising and setting of suns w/ circadian rhythms)
synchronizes
