Term | Definition |
The _________ Houses an Endogenous Circadian
Clock | Hypothalamus |
________ rhythms are regular fluctuations in a living
process | Biological |
Biological rhythms include which three rhythms? | circadian, ultracadian, and infradian |
Circadian rhythms have a rhythm of about _#_ hours | 24 |
Ultradian rhythms repeat more than once a day and include things like... | bouts of activity, feeding,and hormone release |
Infradian rhythms repeat less than once a day and include things like... | body weight and reproductive cycles |
Biological rhythms are regular _________ in a living process | fluctuations |
________s are active during the light
________s are active during the dark | Diurnal, Nocturnal |
A ______ shift is the shift in activity in response to a
synchronizing stimulus, such as light or food | phase |
_________ is the process of shifting the rhythm | Entrainment |
The cue that an animal uses to synchronize with the
environment is called a _______ or “time-giver” | zeitgeber |
The biological clock is located in the _____________ ________—above the optic chiasm in the hypothalamus | suprachiasmatic nucleus (SCN) |
SCN-lesioned animals showed what? | disrupted circadian rhythms |
Isolated SCN cells maintain electrical activity that is what? | synchronized to the previous light cycle |
__________ studies proved that the SCN produces a circadian rhythm | Transplant |
Hamsters with SCN lesions received a SCN tissue transplant from hamsters with a very short period, ~20 hours. What was the result? | Circadian rhythms were restored but matched the shorter period of the donor |
Circadian rhythms entrain to light-dark cycles using different
pathways, some outside of the eye | ;) |
The pineal gland in amphibians and birds is sensitive to _____ | light |
________ is secreted from the pineal gland to inform
the brain about light | Melatonin |
In mammals, light information goes from the eye to the
SCN via the ___________ pathway | retinohypothalamic |
retinohypothalamic pathway: Some retinal ________ cells project to the SCN | ganglion |
retinohypothalamic pathway: Most of the retinal ganglion cells contain ________, a special photopigment, that makes them sensitive to light | melanopsin |
SCN cells in mammals make two proteins: | Clock & Cycle |
Clock and Cycle proteins bind together to form a what? | dimer |
The Clock/Cycle dimer binds to DNA and promotes the transcription of 2 genes: | Period (per) and Cryptochrome (cry) [Per and Cry proteins bind to each other and to protein Tau] |
Molecular clock: The Per/Cry/Tau protein complex enters the nucleus and ______ the transcription of per and cry | inhibits |
Molecular clock: What does this inhibition cause? | No new proteins are made until the first set degrades, The cycle repeats ~every 24 hours |
mutations of _____ gene in Drosophila helped understand
circadian clock in mammals | period |
Gene ________ show how important the clock is to
behavior in constant conditions: | mutations |
In tau mutations the period is ______ than normal | shorter |
Double Clock mutants are severely _________ | arrhythmic |
Sleep is synchronized to _______ events, including light and dark | external |
In the absence of cues, humans have a freerunning period of
approximately _#_ hours | 25 |
Electrical brain ________can be used to classify levels of arousal and states of sleep | potentials |
Electroencephalogram (EEG): continuous scalp recording;
summed Post-Synaptic Potentials (____ and ____) of
synchronously firing pyramidal cells in neocortex | IPSP and EPSP |
There are Two distinct classes of sleep: | Slow-wave sleep (SWS) and Rapid-eye-movement sleep (REM) |
Slow-wave sleep (SWS) can be divided into _#_
stages and is characterized by slow-wave EEG activity | 4 |
Rapid-eye-movement sleep (REM) is characterized
by small ________, fast-EEG waves, no postural
tension, and rapid eye movements | amplitude |
The pattern of activity in an awake person contains many
__________ | frequencies: |
These frequencies are dominated by waves of ____ frequency and ___ amplitude (15 to 20 Hz)
• Known as beta activity or desynchronized EEG | fast, low |
Alpha rhythm occurs in _________, a regular oscillation of
8 to 12 Hz | relaxation |
Four stages of slow-wave sleep: Stage 1 sleep shows events of ________ frequency and _______ amplitude, as well as vertex spikes, or sharp waves | irregular, smaller |
Four stages of slow-wave sleep: Stage 1 sleep causes what physical things to happen? (3) | Heart rate slows, muscle tension reduces, eyes move about |
Four stages of slow-wave sleep: how long does Stage 1 sleep last? | Lasts several minutes |
Four stages of slow-wave sleep: Stage 2 sleep is Defined by waves of 12 to 14 Hz that occur in bursts, called _____ _________ | sleep spindles |
Four stages of slow-wave sleep: in Stage 2 sleep, K-complexes appear which are what? | —sharp negative EEG potentials |
Four stages of slow-wave sleep: Early stage 3 sleep Continues _____ _________ as in stage 2 | sleep spindles |
Four stages of slow-wave sleep: Early stage 3 sleep is Defined by the appearance of _____-amplitude, very slow waves called _____ waves | large, delta |
Four stages of slow-wave sleep: Early stage 3 sleep: how often do Delta waves occur? | about once per second |
Four stages of slow-wave sleep: in Late stage 3 sleep Delta waves are present about ____ the time | half |
Four stages of slow-wave sleep: ___ sleep follows SWS | REM |
REM sleep: Active EEG with _____-amplitude, _____-frequency waves, like an awake person | small, high |
REM sleep: Muscles are relaxed—called _______ sleep | paradoxical |
Vivid dreams occur during REM sleep, characterized by: | Visual imagery and Sense that the dreamer is “there” |
_________ are frightening dreams that awaken the
sleeper from REM sleep | Nightmares |
______ _______ are sudden arousals from stage 3 SWS,
marked by fear and autonomic activity | Night terrors |
Nearly all mammals display both REM and SWS. Birds also display both REM and SWS sleep. Dolphins don’t show REM sleep however, because why? | relaxed muscles are incompatible surface breathing |
In dolphins and birds, only one brain hemisphere enters SWS
at a time; the other remains _______ | awake |
Typical young adult sleep 7–8 hours/night: __-__% in stage 2; __% in REM | 45–50, 20 |
Typical young adult sleep 7–8 hours/night: Cycles last __-___minutes | 90–110 |
Typical young adult sleep 7–8 hours/night: In Earlier cycles, there's more ___ ; later cycles more ___ | stage 3 SWS, REM |
Infant sleep is characterized by: (2) | Shorter sleep cycles and More REM sleep – 50%, which may
provide essential stimulation to the developing nervous system |
As we age, what happens to our sleep and wake times? | sleep time declines and wake time increases |
The biggest loss is time spent in stage _#_:
– By 60, only half as much time is spent as at age 20
– By 90, it has disappeared | 3 |
sleep deprivation: Effects can vary with age and other factors. But what are three common effects? | Increased irritability, Difficulty in concentrating, and Episodes of disorientation |
Randy Gardner’s HS science fair project - How long could
he go without sleep? He managed _#_ consecutive
days with no signs of insanity | 11 |
______ _________ is the process of sleeping more than
normally, after a period of deprivation | Sleep recovery |
Sleep recovery: Night 1 | stage 3 sleep is increased, but stage 2 is decreased |
Sleep recovery: Night 2 | most recovery of REM sleep, which is more intense than normal with more rapid eye movements |
Sleep deprivation can be fatal: Total sleep deprivation compromises the ________ ________ and leads to death | immune system |
The disease _____ ________ insomnia is inherited – in
midlife people stop sleeping and die 7–24 months after
onset of the insomnia | fatal familial |
Degeneration of ______ ______ was found in patient with fatal familial insomnia; | frontal cortex |
The bodies need sleep for what 4 things? | Energy conservation, Niche adaptation, Body restoration, and Memory consolidation |
Sleep may aid memory consolidation: Sleep during the interval between learning and recall may reduce what? | interfering stimuli |
Sleep may aid memory consolidation: Memory typically _____ and sleep may slow this down | decays |
Sleep may aid memory consolidation: Or sleep, especially ___, may actively contribute through processes that consolidate the learned material | REM |
Sleep is an active state mediated by what 4 interacting neural systems? | forebrain, brainstem, pontine, and hypothalamic systems |
A forebrain system—displays ____ | SWS |
A brainstem system—activates the _______ | forebrain |
A pontine system—triggers ____ _______ | REM sleep |
A hypothalamic system—does what? | affects the other three systems |
_________ experiments showed that different sleep
systems originate in different parts of the brain | Transection |
The isolated brain is made by an incision between the
________ and the _______ ______ | medulla and the spinal cord |
Animals with this incision showed signs of sleep and wakefulness, proving what? | that the networks reside in the brain |
An isolated forebrain is made by an incision in the
________ | midbrain |
The electrical activity in the forebrain showed constant SWS, but not REM—thus, the forebrain alone can generate ____ | SWS |
The constant SWS activity in the forebrain is generated by
the ______ _______, a ventral region | basal forebrain |
Neurons in this region become active at sleep onset and
release _____ | GABA |
GABA activates receptors in the nearby ___________ nucleus | tuberomamillary |
GABA receptors are also stimulated by general _________ to produce slow waves resembling SWS | anesthetics |
What is able to activate the cortex? | The reticular formation . |
Electrical stimulation of this area will _____ __ sleeping
animals | wake up |
Lesions of this area promote ______ | sleep |
The forebrain and reticular formation seem to guide the
brain between ___ and ___________ | SWS and wakefulness |
An area of the pons, near the locus coeruleus, is
responsible for what kind of sleep? | REM sleep (Some neurons in this region are only active during REM sleep ) |
this area of the pons inhibit motoneurons to keep them from firing, which disables what during REM? | disabling the motor system during REM sleep |
The study of _________ revealed the hypothalamic sleep
center. | narcolepsy |
Narcolepsy sufferers have frequent what? | sleep attacks and excessive daytime sleepiness |
Narcolepsy sufferers do not go through ___ before REM sleep | SWS |
Narcolepsy sufferers may show _________—a sudden loss of muscle tone, leading to collapse | cataplexy |
Narcoleptic dogs have a mutant gene for a _______
receptor | hypocretin |
Hypocretin normally prevents what? | the transition from wakefulness directly into REM sleep |
Interfering with hypocretin signaling leads to
________ | narcolepsy |
Hypocretin neurons in the hypothalamus project to other
sleep system centers: (3) | the basal forebrain, the reticular formation, and the locus coeruleus |
Axons also go to the tuberomamillary nucleus, whose
inhibition induces what? | SWS |
The ___________ seems to contain a hypocretin sleep that
controls wakefulness, SWS sleep, or REM sleep | hypothalamus |
______ _________ is the brief inability to move just before
falling asleep, or just after waking up | Sleep paralysis |
sleep paralysis may be caused by the _______ _______ continuing to signal for muscle relaxation, even when awake | pontine center |
Sleep disorders in children: Night terrors and sleep enuresis (bed-wetting) are associated with what kind of sleep? | SWS |
Sleep disorders in children: Somnambulism (sleepwalking) occurs during stage _#_ SWS, and may persist into adulthood | 3 |
REM behavior disorder (RBD) is characterized by what? | organized behavior from an asleep person (fighting an imaginary foe for example) |
RBD usually begins after age 50 and may be followed by
beginning symptoms of Parkinson’s disease. This suggests what? | damage in the brain motor systems |
____-_____ insomnia is a difficulty in falling asleep, and
can be caused by situational factors, such as shift work or
jet lag | Sleep-onset insomnia |
_____-________ insomnia is a difficulty in staying
asleep and may be caused by drugs or neurological
factors | Sleep-maintenance insomnia |
In ______ _______, breathing may stop or slow down when muscles in the chest and diaphragm relax too much or respiratory neurons in the brain stem don’t signal properly | sleep apnea |
Sleep state misperception occurs when what? | people report insomnia even when they were asleep |
________ _______ _______ __________ is sleep apnea
resulting from immature respiratory pacemaker systems
or arousal mechanisms | Sudden infant death syndrome (SIDS) |
what can prevent the infant from suffocation due to apnea? | Putting babies to sleep on their backs |
Most sleeping pills bind to ____ receptors throughout the
brain | GABA |
Continued use of sleeping pills can cause what 3 things? | • Makes them ineffective
• Produces marked changes in sleep patterns that
persist even when not taking the drug
• Can lead to drowsiness and memory gaps |