Ruff- Sleep/ARAS Flashcards
Beta waves on an EEG: describe and give example
Highest Frequency
Lowest amplitude
Ex. eyes open, active thinking
Alpha Waves on an EEG: describe and give example
Highish Frequency
Lowish amplitude
Ex. eyes closed, relaxed
Theta waves on an EEG: describe and give example
Low frequency
High amplitude
Ex. Drowsiness, meditation
Delta waves on an EEG: describe and give example
Lowest Frequency
Highest Amplitude
Ex. Slow Wave Sleep
What does a seizure look like on an EEG?
Super Frequent and high amplitude waves
A Generalized seizure is when all the electrodes register crazy waves movements
A Complex Partial Seizure is when a particular region (many times one side of the brain) registers crazy wave movements
Describe the relationship between the EEG readings and the stages of sleep
As you move from stage 1 to stage 4 sleep the waves get progressively higher amplitudes, but get less frequency.
After you reach stage 4 you go to REM sleep where you go back to the amplitude and frequency of stage 1 and almost the awake stage (slightly higher amplitude)
After first reaching REM, you continue to sleep. Describe the stages after this.
Get to REM then you bounce around between sleep stages and go back to REM. It has no pattern.
BUT you usually don’t go back to stage 4 again.
Describe what happens when you sleep according to an EMG
- When awake you have strong tonic muscle tone.
- When you enter non REM sleep you lose a little muscle tone.
- When you enter REM Sleep you lose a little more muscle tone.
- -BUT YOU ALWAYS HAVE MUSCLE TONE–
Describe what happens when you sleep according to an Electrooculography EOG
Non-Rem sleep you get frequent low amplitude stimuli.
In Rem sleep you high amplitude stimuli similar to if you were awake (REM= Random Eye Movement)
Sleep Apnea: What is it, what does it do to sleep stages
- When you fall asleep your palate muscles don’t keep tone and your airway collapses
- You can get to stage 1 and rarely stage 2, but you will wake up due to lack of oxygen
- treat with CPAP
The ascending reticular activating system (ARAS): what is it, what does it do, where does it act
- promotes wakefullness
- Group of nuclei in the brainstem, hypothalamus, and basal forebrain
- Use monoamines and acetylcholine
- project to cortex and thalamus
ARAS’s monamenergic division: what neurotransmitters it uses, what are its nuclei
- uses histamine (HA), dopamine (DA), serotonin (5-HT), norepinephrine (NE)
- Nuclei include: Tuberomammilary (HA), Substantia Nigra/ventral tegmental (DA), locus ceruleus (NE), Raphe Nuclei (5-HT)
ARAS’s Cholinergic Division: what neurotransmitter it uses, what are its nuclei
- Uses acetylcholine
- Nuclei include: Basal Forebrain, Laterodorsal tegmental, pedunculopontine tegmental nuclei (all ACh)
Orexin: what is its role in sleep/wake stuff, what happens if you lose it
- Sustains wakefulness, promotes arousal
- complete loss: Narcolepsy (can’t stay awake)
- partial loss in parkinson’s and traumatic brain injury (explains why you get tired)
- Orexin antagonists are used as sleep aids
Orexin: where is it in the brain,
-found in lateral hypothalamus for wake/sleep cycle effects
Melanin-Concentrating Hormone: where is it, what does it do
- found in lateral hypothalamus
- Promotes REM Sleep
Preoptic Area: function, nuclei here, neurochemicals
- Promotes sleep (switch between sleep and awake)
- Ventrolateral pre-optic (VLPO) nucleus is here
- Median pre-optic nucleus is here
- Neurochemicals: GABA primarily, Galanin secondary
Thalamic Reticular Nucleus
-it is inhibitory to the entire thalamus
Non-Rem Sleep characteristics and pathways
- decreases in HR, BP, metabolic rate, temp
- Thalamus goes into bursting mode
- Reticular nucleus inhibits thalamus
- Reticular nucleus is excited by the cortex and thalamus
What is meant by bursting mode
- The way the thalamus fires in non-REM sleep
- The reticular cell fires in bursts
- best if you look at the diagram in the lecture notes
Rem Sleep pathways and characteristics
- LDT and PPT inhibit reticular nucleus and excites the thalamus
- Reticular nucleus can no longer inhibit the thalamus
- get rapid eye movements
- similar to being awake
Why do you get weird dreams (uninhibited dreams)
- dorsolateral prefrontal cortex is the inhibitory part of the brain that stops you from doing socially weird stuff
- gets shut off when you sleep
look at diagram for motor suppression in REM sleep
DO IT YOU LAZY NINJA!
REM Behavior Disorder
- Loss of REM atonia (get muscle tone)
- more common in the old folks
- can have small or large movements (might act out dreams)
- 80% of these people get other diseases (parkinson’s, lewy bodies)
Is REM sleep absolutely necessary to prevent death
No. Stage 3 and 4 is good enough to survive
Function of sleep
- replenish energy expenditure
- consolidation of memories
- clearance of metabolites
Adenosine sleep theory
- Adenosine is possible somnogen
- byproduct of atp
- binds adenosine receptors
- inhibits ARAP, disinhibits VLPO
