Sleep

Question 1

Circadian rhythm

Answer 1

physiological processes that vary around the 24 hour day include activity, alertness, gene expression, organ physiology, and hormone secretion

Question 2

Characteristics of Circadian rhythms

Answer 2

1. Cyclic
2. Self-sustaining
3. Entrainable

Question 3

The free-running rhythm

Answer 3

In the absence of zeitgebers, activity patterns cycle with an endogenous pattern

Question 4

Phase-shift

Answer 4

Drift out of phase with 12 hour day/light cycle

Question 5

suprachiasmatic nucleus (SCN)

Answer 5

The master pace-maker located in the hypothalamus. SCN generates internal circadian rhythms in gene expression, electrophysiology, and hormone secretion.

Question 6

photosensitive retinal ganglion cells

Answer 6

projections from RGCs transfers information about light and dark to SCN which synchrnoizes a phase of SCN rhythms with the external enviornment

Question 7

SCN outputs

Answer 7

hypothalamus, hippocampus, cortex, and brain stem

Question 8

Clock genes

Answer 8

1. Clock and BMAL1
2. CRY and PER
3. REV and ROR
4. CCG

Question 9

The Circadian gene process

Answer 9

1. BMAL1-Clock complex activates the transcritpion of CRY and PER which inhibit BMAL1-Clock
2. REV negatively regulates the expression of BMAL1 while ROR positively regulates it
3. BMAL1-Clock regulates the expression of CCG which modulates essential physiological processes

Question 10

Sleep

Answer 10

Readily reversible state of reduced responsiveness and interaction with the environment

Question 11

Why do we sleep?

Answer 11

Restoration and adaptation

Question 12

Non-REM

Answer 12

an idling brain in a movable body

Question 13

REM

Answer 13

an active, hallucinating body in a paralyzed body

Question 14

SWS

Answer 14

stage 3 and 4

Question 15

Stage 1

Answer 15

Low amplitude high freq

Question 16

Stage 2

Answer 16

sleep spindles of high amplitude and high frequency that last for a few seconds

Question 17

REM Sleep properties

Answer 17

Increased:
1. eye movement
2. heart rate
3. respiratory rate
4. penile erection

Decreased: muscle tone

Question 18

Wakefulness neuronal activity

Answer 18

acethylcholine, noreprinephrine, serotonin, histamine, and orexin active

Question 19

REM Sleep neuronal activity

Answer 19

Neurons releasing noreprinephrine and serotonin are inactive. Neurons releasing acethycholine are active

Question 20

Slow Wave Sleep activity

Answer 20

Neurons releasing noreprinephrine, serotonin, and acethycholine decrease activity

Question 21

Neural mechanisms of dreaming

Answer 21

1. Increased neuronal activity in brain stem (midbrain and pons), limbic system (amygdala and hippocampus), thalamus, and visual cortex
2. Decreased neuronal activity in the PFC
3. Neural activity in the brain stem activated the thalamus and visual cortex to generate info
4. dopaminergic neurons in VTA activate the limbic system and induce strong emotions

Question 22

The two process model of sleep

Answer 22

Process S - Build up of homeostatic sleep drive
Process C - Circadian signaling

Question 23

Adenosine

Answer 23

1. Builds up in brain during wakefulness due to energy consumption
2. Increase throughout the day
3. Blocked by caffine

Question 24

Melatonin

Answer 24

1. Hormone secreted by pineal gland in brain
2. Helps maintain daily schedule of waking up and sleeping
3. Inhibited by daylight

Question 25

Regulation of Melatonin Production

Answer 25

The SCN via an inhibitory projection to the paraventricular nucleus of the hypothalamus controls the sympathetic output to the pineal gland which is responsible for melatonin secretion. The presence of light activates SCN neurons to inhibit the secretion of melatonin. Darkness suppresses the inhibition and facilitates the secretion of melatonin.

Question 26

Deep Sleep Promotes Memory Consolidation

Answer 26

1. Object location task in the presence of an odor
2. Re-expsoure to the odor during SWS enchnaced spatial memories and induced stronger hippocampal activation than during wakefulness.
3. Reactivation of memory traces occurs during SWS