Sleep W23 part 2

Question 1

a) Describe selective REM sleep deprivation
b) what happened wrt REM bouts during the experiment?
c) What were the results after the rem sleep deprivation study?
d) what was the conclusion?

Answer 1

a) subjects are woken up every time they are about to enter REM sleep
b) as the number of night INC w/ REM interruption the number of times that the body would attempt to enter REM sleep INC
c) 2 to 3 nights after the experiment the subjects would show compensatory INC REM sleep known as REM rebound
c) REM sleep is important for the body

Question 2

a) According to the default theory of REM sleep what is the fxn of REM sleep?
b) Which one is easier to maintain REM or NREM sleep?

Answer 2

a) it’s the brain’s default state during sleep which is similar to when one is awake.
b) REM

Question 3

T or F - wakefulness substituted for REM thus no REM rebound occurs while awake

Answer 3

T

Question 4

Describe the relationship b/w sleep and memory during the following
a) REM sleep
b) NREM sleep

Answer 4

a) it reactivates and replays memory traces that were formed during the wakeful period. And also aids w/ memory consolidation
b) refines the memory traces by reducing unused connection w/in the brain (pruning)

Question 5

a) Describe how sleep influences recuperation/the immune sys
b) how does this influence brain disorders?

Answer 5

a) during sleep, the lymphatic sys drains toxins from the extracellular fluid
b) the removal of the toxins may reduce the onset of certain brain disorders (such as alzheimers)

Question 6

What does circadian mean?

Answer 6

about a day

Question 7

What dictates the circadian cycle?

Answer 7

its tuned to the duration of the light-dark cycle of the planet

Question 8

Describe the following. provide an example of 1 organism that is w/in each
a) diurnal
b) nocturnal

Answer 8

a) active during the day while sleeping at night - humans
b) active at night while sleeping during the day - mice, rats, bats

Question 9

What type of cues are involved w/ the circadian cycle?
a) biological
b) physiological
c) environmental
d) psychological
e) visual

Answer 9

c

Question 10

describe zeitgebers

Answer 10

environmental cues that cause the circadian rhythm

Question 11

describe the following
a) free-running rhythms
b) free-running period

Answer 11

a) circadian rhythms that do not depend on environmental cues (zeitgebers) to keep them on a regular schedule
b) the duration of one cycle of free-running circadian rhythm

Question 12

T or F - circadian rhythms rely on zeitgebers thus the schedule is disrupted during a free-running rhythm

Answer 12

F - free-running rhythms are circadian rhythms that can maintain their schedule despite the constant environment

Question 13

our internal biological clock tends to run a little slow unless _______.

Answer 13

it is being entertained by time-related cues in the environment

Question 14

a) what is the circadian clock
b) what part of the brain (be specific) regulates the circadian clock?

Answer 14

a) its an endogenous timing mech
b) the suprachiasmatic nucleus of the medial hypothalamus

Question 15

ANS the following wrt the suprachiasmatic nucleus
a) when are the neurons w/in the SCN the most activity?
b) what would occur to the sleep/wake cycle if the SCN was lesioned?
c) how does the SCN influence light/dark entrainment

Answer 15

a) during the day
b) disrupts it but doesn’t eliminate the cycle all together
c) it contains the mech needed to match the internal clock w/ external stimuli (light)

Question 16

a) What would happen if you removed the SCN from hamsters that have a free-running sleep-wake cycle mutation (shorter than normal). Then you transplant those mutated SCN into a normal hamster that had their SCN lesioned?
b) what if you reversed this process (put normal SCN into mutant hamsters)

Answer 16

a) it restored the free-running sleep-wake cycles but they were shorter just like it was for the mutant hamsters
b) it restored the free-running sleep-wake cycle to the regular duration

Question 17

Which of the following sits would result in the elimination of the light-dark cycles to entrain the circadian rhythms (match the environment to the internal clock)
a) cleaving the optic tract
b) cleaving the retinohypothalamic tract
c) cleaving the optic chiasm
d) cleaving the optic nerve

Answer 17

b

Question 18

What is the purpose of the retinohypothalamic tracts?

Answer 18

the tract that mediates the ability of light to entrain circadian rhythms

Question 19

What is the significance the melanopsin?

Answer 19

it’s a specialized pigment in the retina that’s used for light entrainment of the circadian rhythm by responding to changes in background illumination