Arousal & Sleep

Question 1

Arousal System: Locus Coeruleus (Dark Blue Place)

Answer 1

Part of Reticular Formation in Pons
- vigilance
–> widespread connections, including thalamus, cortex & hippocampus - playing a role in establishing memory
–> releases burst of Norepinephrine(NE) - amphetamines (NE-agnist) increase alertness

detecting potential danger even from a small “huh/ah” and alerting the memory system so to log and know what to do in this situation if it happens again

Question 1

Arousal System: Reticular Formation

Answer 1

“Net” from Medulla & Pons > throughout the forebrain: also receives info from all sensory systems
–> stimulated by sensory input, pain,touch,temp etc
- alerts brain (the core arousal system), stimulating thalamus and basal forebrain via ACh and Glutamate

Question 2

Basal Forebrain

Answer 2

Release ACh thruout cortex for arousal and GABA to inhibit cortex (one is always active while the other is inactive)
- damage to basal forebrain = Alzheimers disease; arousal critical to memory activation

• Adenosine, by product of cell metabolism, build up thru day, released in brain, inhibits basal forebrain release of ACh
  –> allows GABA to dominate = sleepy time
  —–> caffeine blocks adenosine receptors staying awake

Question 3

EEG - Eledctro Encephalogram

Answer 3

gross average charge in electrical potentials in area under electrode (leases the gross average change)
- more activity = more energy changes

Question 4

What does awake, active look like?

Answer 4

Beta Activity = 18-24 Hz
Very High Frequency
Very desynchronized
- ur awake a lot of brain things happening

Question 5

What does awake, relaxed look like?

Answer 5

Alpha Activity = 8-12 HZ
Somewhat lower frequency than awake/active
somewhat desynchronized

• like mediation, being more alert and more clear minded

Question 6

What is sleep 1?

Answer 6

Theta Activity = 4-7 Hz
lower frequency
still quite irregular
significant more synchronized

Question 7

what is sleep 2

Answer 7

mostly theta activity but with many interspersed (mixed in) Spindles and K complexes
- spindle and k complex = intermittent burst of high freq/ or voltage as brain steeple into deep sleep
(burst of activity is deep to dream, active Brain)

Question 8

Spindle and K Complex (Sleep 2)

Answer 8

K Complex = Brief period delta activity
Spindles = help gate external stim into deeper sleep

Question 9

What is Sleep 3?

Answer 9

Delta Activity
< 4 Hz in less than 50% of this stage
very low freq voltage
very synchronized

Question 10

What is Sleep 4?

Answer 10

Delta Activity in more than 50% of stage
hardest to wake

Stage 3 and 4 = slow wave sleep

• so as u move deeper into sleep –> freq decrease & voltage increase as brain activity become synchronized
• hear rate/breathing decrease and brain less responsive to external stim

Question 11

What is Rem? (“Paradoxical Sleep”)