EEK and sleep - Karius

Question 1

The main driver of circadian rhythm is _ nucleus of hypothalamus that fire day or night.

Answer 1

suprachiasmatic

Question 2

Circadian rhythm is said to have genetic players. what gene genes are said to increase/decrease in creating the circadian rhythm?

Answer 2

Clock (CLK) and BML1

Question 3

CLK and BMAL1 increases transcription/translation of what genes/products?

Answer 3

Period (per1, 2, 3) and Cryptochrome genes (Cryp 1 ,2)

Question 4

What inhibits CLK and BMAL1?

Answer 4

products of period genes and cryptochromes genes

Question 5

When do BMAL/CLK peak their activity?

Answer 5

through the night and decrease in activity through day.

- Per/Cryp have the same cycle but shifted by few hours after BMLA and CLK

Question 6

In entrainment (making day match day), what tract neural tract is followed?

Answer 6

retino-hypothalamic tract which is a direct relay to hypothalamus and does not use visual cortex

Question 7

In entrainment, What neurotransmitter is involved in relating to day ? Night?

Answer 7

Glutamate for day

Melatonin for night

Question 8

what is the sleep pattern as we start to fall alseep?

Answer 8

Within 1st hr we go into deep sleep and then as the night progresses we come out of deep sleep and stay in NREM sleep.

Question 9

in what kind of sleep do we most most of our time in?

Answer 9

NREM

Question 10

what happens to the EEK waves as we go deeper into sleep?

Answer 10

they become less frequent and higher in amplitude –> gradual dissociation of cortex and thalamus.

Question 11

in what sleep do we have our crazy weird dreams?

Answer 11

REM

Question 12

Explain REM in terms of EEK

Answer 12

low amplitude, high frequency waves. Eyes moving rapidly left/right

Question 13

what brain area is crucial to sleep induction?

Answer 13

ventral preoptic area

Question 14

the perception of the need for sleep is linked to what nucleoside?

Answer 14

• adenosine (MAIN one)
• IL1b and TNFa during illness (any trigger NFkb and production of NO can induce sleep)
• GHRH

Question 15

Explain the pathway leading to sleep

Answer 15

tiredness triggers accumulation of PGD2 in peripheral blood when then bind to receptor on endothelial cells. This leads to release of adenosine from the cell into CSF. Adenosine then binds to 2a receptor of neurons in ventral preoptic area.

Question 16

Explain how REM sleep is initiated

Answer 16

cholingergic neurons in lateral pontine tegmentum release Ach in the geniculate body which then sends input to the occipital cortex

Question 17

What nucleus is involved in muscle paralysis in REM sleep?

Answer 17

locus ceruleus , sends inhibitory input to a-motorneurons and spares the diaphragm and small muscle groups

Question 18

Describe how arousal from sleep occurs

Answer 18

Lateral hypothalamus contains orexin A and B (aka hypocretin 1 and 2 in the brain). Orexigenic inputs are sent to tuberomamillary nucleus leading to histamine release. Histamine released into locus ceruleus binds to H1 receptor, activating LC nucleus which release Norepi and suppress REM sleep

Question 19

Indicate when each of these waves occur:
A. Alpha waves
B. Beta waves
C. Gamma waves
D. Theta waves
E. Delta waves

Answer 19

A. during quiet wakefullness (thinking) with eyes closed. Most prevalent over occipital cortex
B. Alert wakefulness with eyes open
C. occur someone is aroused or focused on something
D. Normal in kids, in adults occur when frustrated or disappointed; can also occur in sleep
E. Deep sleep in adults; infants, appearance during wakefulness means serious brain disease

Question 20

What is alpha block?

Answer 20

The end of alpha wave marked by opening of eyes producing beta waves

Question 21

Describe each of the EEK waves in terms of frequency and amplitude and what it’s associated with

Answer 21

1. Alpha wave: awake,eyes closed; high freq/low amp; occipital cortex
2. Beta: wake, eyes open; high freq/low amp; frontal, parietal cortex
3. gamma: slower; associated with attention/motor planning
4. Theta: slower, higher amp; frustration, sleep
5. Delta: slowest, largest; deep sleep dissociation of cortex and thalamus

Question 22

during what phase of development do adult alpha wave start to appear?

Answer 22

adolescence

Question 23

what factors decrease the frequency of alpha waves?

Answer 23

• hypoglycemia
• low body temp
• low adrenal glucocorticoids
• high PaCO2

Question 24

The following characteristics are of what sleep stage:

• increasing voltage EEK
• slowing of frequency
• Sleep spindles
• K complexes
• EMG shows muscle activity, but relatively quiet

Answer 24

Stage 2 = N2 (true sleep)