Overview

Question 1

Circadian Rhythms

Answer 1

Biological rhythms that last “about a day”. (Are usually >24 hours, due to the need to reset and adjust to fit the 24 hour rotation of the Earth, hence why zeitgebers are important)

Question 2

Diurnal

Answer 2

Active during the day (light periods)

Question 3

Zeitgebers

Answer 3

(German: “time giver”) - cues from the environment used to entrain an animal’s circadian rhythm
(sunlight is the most effective zeitgeber for humans)

Question 4

Entrainment

Answer 4

The process of synchronizing one’s biological rhythm to a cue in the environment.
An example would be adjusting how much you sleep.

Question 5

When lighting is constant however (no night), the hamster goes to sleep and wakes up at ____

Answer 5

Roughly the same time so circadian behavior is influenced by light/dark, but not totally.
Demonstrates free-running rhythms

Question 6

Suprachiasmic nucleus (SCN)

Answer 6

The brain has a biological clock with 24-hour periodicity, the _____

Question 7

The SCN releases chemicals that affect

Answer 7

• Lower body temperature
• Lower blood pressure
• Digestion

Question 8

We stick to circadian rhythms because of the internal biological clock, known as the _____ and external cues, known as

Answer 8

Suprachiasmic nucleus (SCN); zeitgebers

Question 9

The _____ send messages to the SCN to tell when it’s light or when it is dark.

Answer 9

Optic nerves

Question 10

Photopigment within certain retinal ganglion cells that project to the SCN. Does not mediate vision, but tells SCN whether it is light or dark.
Not for vision but for entrainment.

Answer 10

Melanopsin

Question 11

When it is light, melanopsin containing retinal ganglia ____ hormone release by the SCN

Answer 11

Inhibit

Question 12

When it is dark, melanopsin containing retinal ganglia set-off a chain reaction, ultimately causing the Pineal gland to release a hormone called _____

Answer 12

Melatonin

Question 13

Brain recording using _____ enables researchers to observe the brain’s behavior/activity, even without the participant having to be awake

Answer 13

Electroencephalogram (EEG)

Question 14

There are 4 distinctive stages of sleep, and one additional type of sleep that occurs during stage 1, called ______ sleep.

Answer 14

Rapid Eye Movement (REM)

Question 15

Awake/alert

Answer 15

• fast (13-30 Hz, beta)
• low amplitude EEG waves
• very small and fast
• beta has the smallest peaks
• decent amount of mental activity

Question 16

Eyes closed, relaxed

Answer 16

• slower (8-13 Hz, alpha)
• higher amplitude EEG waves

Question 17

Stage 1

Answer 17

Stage ___ has even slower (4-8 Hz, theta), low amplitude EEG waves

Question 18

Stage 2

Answer 18

Stage ___ is where EEG looks like stage 1, punctuated by K-complexes and sleep spindles

Question 19

Stages 3 & 4

Answer 19

Stage _ & _ have slow-wave sleep (SWS) characterized by predominantly high amplitude delta (1-4 Hz) rhythms

Question 20

Non-REM (NREM)

Answer 20

• Initial stage 1 and stages 2-4 without REM are called _____. The EEG during REM sleep looks like the EEG during wakefulness.

Question 21

Down-states; theta and delta

Answer 21

Stage 2 K-complexes reflect neuronal __ and lead to ___ and ___ waves in slow-wave sleep (SWS) in stages 3 and 4

Question 22

Postsynaptic potentials (PSPs)

Answer 22

Neurons like to have resting _____ that are either “up” (slightly depolarized, ready for action potential) or “down” (slightly hyperpolarized, silent and not ready to fire an action potential)

Question 23

Thalamus

Answer 23

When cortical neurons are in “down-states”, they are less receptive to input from the _____. In other words, these down-states inhibit sensory input/arousal.

Question 24

Motor pathways

Answer 24

Most are inhibited during REM to prevent a person from acting out his or her dreams (therefore sleepwalking or sleep talking cannot occur during REM)

Question 25

Paradoxical sleep

Answer 25

REM is sometimes called a paradox because its EEg looks like wakefulness. Brain (EEG) and eye (EOG) activity of awake person and REM sleeper look almost identical.

Question 26

REM sleep

Answer 26

Dreaming is not necessarily equated to REM sleep, although >80% dreaming takes place in REM dreams: emotional, illogical, sudden shifts in plots.
- Non-REM dreams: shorter, commonplace themes

Question 27

Insomnia

Answer 27

20+ minutes to fall asleep
- Waking too early
- Not being able to fall back asleep if woken in middle of the night

Question 28

Melatonin, Depressant drugs (Benzodiazepines –> Valium, Xanax), Non-benzos (e.g., Ambien), alcohol)

Answer 28

Insomnia is treated by pharmacological treatments like _____

Question 29

Cataplexy

Answer 29

Sudden loss of muscle tone (despite being fully conscious)

Question 30

Orexin

Answer 30

____ neurons in the hypothalamus serve as a sleep/wake “switch”. Project to other sleep-related brain regions. Keeps sleep “at bay”, prevent rapid progression from wakefulness to REM sleep

Question 31

Hypothalamic orexin neurons

Answer 31

Symptoms of narcolepsy often co-occur with degeneration of _____

Question 32

Narcolepsy

Answer 32

_____ may be treated with stimulant drugs (e.g., amphetamine), caffeine, or modafinil (e.g., Provigil)