Lecture 22

Question 1

What is echolocation?

Answer 1

The emission of sound in order to localize objects based on echoes (outgoing signal=chirp) (incoming signal=echoe)

Question 2

How do we find out how humans use echolocation?

Answer 2

Compare brain activity (using fMRI) between controls and blind “echolocationg experts”

Question 3

What are some of the findings from human echolocation experiments?

Answer 3

Blind echolocators have more activity in the temporal and visual lobes

Question 4

How do we measure sleep?

Answer 4

EEGs

Question 5

What kinds of rhythms is the waking state associated with?

Answer 5

Beta rhythms-fast activity waves, 15-30hz

Question 6

What rhythms is the drowsy state associated with?

Answer 6

Alpha rhythms-large regular waves, 7-11hz

Question 7

What types of rhythms is deep sleep associated with?

Answer 7

Delta rhythms-large, slow wave activity, 1-3 hz

Question 8

What are the 5 points of sleep?

Answer 8

1. W-Waking, Beta rhythms
2. N1-NREM stage 1, mixed activity (theta waves)
3. N2-NREM Stage 2, sleep spindles (11-16hz)
4. N3-NREM stage 3, delta rhythm
5. R-Rem

Question 9

Whata is rem sleep characterized by?

Answer 9

Twitches and eye movements, atonia (complete muscle inactivty produced by inactivation of motor neurons), sometimes referred to as paradoxical sleep.

Question 10

What are the 2 general categories that sleep can be divided into?

Answer 10

1. NREM dominant-early sleep periods

2. REM dominant-later sleep periods (occurs in 90 minute cycles)

Question 11

How is sleep a biologically adaptive behaviour?

Answer 11

Energy conservation strategy-food gathering occurs at optimal times, energy is conserved for later.

Question 12

What types of animals tend to sleep more/less?

Answer 12

Predators sleep more, prey sleeps less, due to time required to obtain food and predation risk

Question 13

What does energy conservation using sleep help with?

Answer 13

Brain activity, body temperature, posture.

Question 14

What is the basic-rest activity cycle?

Answer 14

Recurring cycle of temporal packets (roughly 90 mins), during which an animals level of arousal waxes and wanes.

Question 15

What is memory consolidation?

Answer 15

The process of stabilizing memory trace after learning

Question 16

What kinds of things can happen if you don’t get enough sleep?

Answer 16

Potential for build up of Alzheimer’s protein, (beta amyloid protein), less metabolic clearance.

Question 17

What is the lymphatic system?

Answer 17

Part of the immune system that aids in the removal of toxins- removal of intersitial fluid from tissues, transport of fatty acids from digestive system, transport of white blood cells.

Question 18

What is the glymphatic system?

Answer 18

Similar system to the lymphatic system in the brain-CSF interacts with interstitial fluid to remove protein by-products (including beta amyloid)

Question 19

What happens with CSF fluid during sleep?

Answer 19

It floods the brain, basically cleaning it up.

Question 20

What is the reticular activating system?

Answer 20

Regulates sleep-stimulation causes a waking state EEG< whereas damage may induce coma (slow wave EEG)

Question 21

What are the 2 systems involved in producing a waking EEG?

Answer 21

1) Basal forebrain- secretes ACh during awake, but mobile periods
2) Median Raphe- secretes 5HT during movement

Question 22

What is the flip-flop switch hypothesis?

Answer 22

Orexin neurons stimulate the reticular activating system, raphe, and basal forebrain causing us to feel more awake. This then goes onto the ventral lateral preoptic nucleus (hypothalamus), which induces drowsy feelings. This signal gets sent to the orexin neurons, and we basically flip flop between sleepiness and awakeness.

Question 23

What are somnogens?

Answer 23

Endogenous substances that increase sleepiness or promote sleep

Question 24

What are the 2 types of somnogens?

Answer 24

Prostaglandin D2- reduces body temp

Adenosine- inhibition in CNS

Question 25

What somnogen does caffeine act on?

Answer 25

Adenosine

Question 26

What is narcolepsy and why is it caused?

Answer 26

Uncontrollably falling asleep at inconvenient times. Caused due to a lack of orexin neurons that stimulate awakeness.

Question 27

What is sleep hygiene?

Answer 27

The controlling of all behavioural and environmental factors that precede sleep and may interfere with sleep

Question 28

What are some ways to improve sleep hygiene?

Answer 28

Fix a bedtime and awakening time, avoid naps, avoid caffeine 4-6 hours before bed, avoid heavy meals immediately prior to sleep, reserve bed for sleep and sex, exercise regularly (But not within 3 hours of bed time)