Exam 3 Material (Sleep Lectures) Flashcards
What is the state that the brain actively produces/ where there is decreased brain activity and decreased response to stimuli?
Sleep
What are internal mechanisms operating on a roughly 24 hr cycle (sleep-wake cycle)?
Endogenous circadian rhythms
What are the internal mechanisms operating on a yearly cycle?
Endogenous circannual rhythms
How long is the human circadian rhythm?
Slightly longer than 24 hours
What is a stimulus that resets the circadian rhythm? (ex: sunlight, tides, exercise/activity, meals, arousal, temperature, etc.)
Zeitgeber
What is the main control center of the circadian rhythm of sleep and temperature (located above/superior to the optic chiasm)?
The suprachiasmatic nucleus (SCN)
What is a special population of ganglion cells that have their own photopigment called melanopsin? (the cells respond directly to light and do not receive any input from the rods or cones)
Retinohypothalamic path
What are two types of genes are responsible for generating the circadian rhythm?
Period and timeless
What produces proteins called PER?
Period
What produces proteins called TIM?
Timeless
What endocrine gland does the SCN regulates and is located posterior to the thalamus?
Pineal gland
What does the pineal gland secrete?
Melatonin (a hormone that increases sleepiness).
What is a combination of EEG (allows researchers to study the stages of sleep) and eye-movement records?
Polysomnograph
What waves are present when one begins a state of relaxation?
Alpha waves
What is the stage of sleep when sleep has just begun (irregular, jagged, and low waves) (brain activity begins to decline)?
Stage 1
What stage of sleep is characterized by the presence of sleep spindles and k-complex?
Stage 2
What are 12-14 Hz waves during a burst that lasts at least half a second?
Sleep spindles
What is a sharp high-amplitude negative wave followed by a smaller, slower positive wave?
K-complex
What stages of sleep together constitute slow-wave sleep (SWS)?
Stage 3 and Stage 4
What are periods characterized by rapid eye movement (also known as paradoxical sleep—-deep sleep in some ways, but light sleep in others)?
Rapid eye movement sleep (REM)
What are stages other than REM sleep referred to as?
Non-REM sleep (NREM)
What stages of sleep predominate early in the night (length of sr=tage decreases as the night progresses)?
Stages 3 and 4
What type of sleep is predominant later in the night (length increases as night progresses)?
REM sleep
What brain mechanism in the midbrain extends from the medulla to the forebrain (responsible for arousal)?
Reticular formation
What brain mechanism in the midbrain contributes to cortical arousal (axons extend to the hypothalamus, thalamus, and basal forebrain, which release acetylcholine and glutamate)?
Pontomesencephalon
What does the stimulation of pontomesencephalon do?
Awakens sleeping individuals and increases alertness in those already awake
When is ACh released?
During REM
What axons release norepinephrine (NE) to the cortex (increase wakefulness/usually dormant while asleep)?
Locus coeruleus
What axons release serotonin (5HT) throughout cortex (disrupts REM cortex/ ACh and 5HT regulate REM sleep)?
Raphe nuclei
What is produced in the hypothalamus (widespread excitatory effects/antihistamines produce sleepiness)?
Histamine
What is a peptide neurotransmitter released in a pathway from the lateral nucleus of the hypothalamus (highly responsible for the ability to stay awake)?
Orexin
What is produced by cells in the basal forebrain (inhibitory/inhibition provided by this is essential for sleep)?
GABA
What does GABA also regulate?
Decreases in temperature and metabolic rate/decreases in neural activity
What causes sleep to be local within the brain?
GABA
When do sleepwalking, lucid dreaming, and sleep paralysis occur?
When one part of the brain is awake and other parts are asleep
What activity increases during REM sleep?
In the pons and temporal cortex
What activity decreases during REM sleep?
In the primary visual cortex, the motor cortex, and dorsolateral prefrontal cortex
What is REM sleep associated with?
A distinctive pattern of high-amplitude electrical potentials known as PGO waves
What is REM regulated by?
Serotonin (interrupts REM)/acetylcholine (initiates REM)
What are the functions of sleep?
Energy conservation and memory consolidation
What increases after new learning?
Sleep spindles
What is the function of REM sleep?
Memory storage (pruning connections/storage of motor skills)
What are the two biological perspectives on dreaming?
The activation-synthesis hypothesis and the clinco-anatomical hypothesis
Which hypothesis on dreams states that dreams begin with spontaneous activity in the pons (PGO waves during REM sleep) diffusely activating cortex?
Activation-synthesis hypothesis
Which hypothesis on dreaming puts less emphasis on pons, PGO waves, and REM sleep/dreams are similar to thinking, just under unusual circumstances (similar to mind wandering)?
Clinico-anatomical hypothesis
What sleep disorder is characterized by frequent periods of sleepiness (gradual attack of sleepiness) (caused by lack of hypothalamic cells that produce and release orexin)?
Narcolepsy
What is a sleep disorder associated with inadequate sleep (caused by a number of factors, including noise, stress, pain, diet, and medication)?
Insomnia
What is the sleep disorder involving repeated involuntary movement of the legs and sometimes the arms while sleeping (usually occurs during NREM sleep/probably not acting out dreams)?
Periodic limb movement disorder
What sleep disorder is associated with vigorous movement during REM sleep (usually associated with acting out dreams/associated with damage to the pons)?
REM behavior disorder
What are experiences of intense anxiety from which a person awakens screaming in terror (usually occurs during NREM sleep/not during a dream state)?
Night terrors
What is a condition similar to sleepwalking but engaging in sexual behavior while asleep (no memory of event)?
Sexsomnia
What is a disruption of the circadian rhythms due to crossing time zones?
Jet lag
What does traveling west do to our circadian rhythms?
Phase-delays
What does traveling east does to our circadian rhythms?
Phase-advances
