Neuroscience of christmas

Question 1

Stages of sleep>

Answer 1

0> resisting sleep/ awake
1> REM sleep
2> Light sleep
3> Deep sleep

Question 2

Stage 1: REM sleep> features

Answer 2

• occurs every 90 minutes
• activity (documented via EEG)= similar to awake EEG
  >rapid eye movements (REM)> due to dreaming
• low amplitude
• hf, fast waves

Question 3

stage 3/4: Deep sleep

Answer 3

• neurons across the brain fire in synchrony
• big waves of activation of high amplitudes, & high voltages
• very low frequency, slow waves
• punctuated with periods of REM sleep

Question 4

Resisting sleep>

Answer 4

• bursts of alpha waves (8-12 Hz) EEG waves
  >alpha waves signal eyes drooping due to sleepiness

Question 5

How many cycles between the stages of sleep approximately occur every night?>

Answer 5

5

Question 6

REM sleep vs slow-wave (deep) sleep> EEG>

Answer 6

• REM: has EEG desynchrony (rapid, irregular waves)
• Slow wave: has EEG synchrony (slow waves)

Question 7

REM sleep vs slow-wave (deep) sleep> muscle tonus

Answer 7

REM sleep: lack of muscle tonus (paralysis)
Slow wave: moderate muscle tonus (no paralysis)

Question 8

REM sleep vs slow-wave (deep) sleep> eye movements>

Answer 8

REM: Rapid eye movements (REM)
Slow sleep: slow or absent eye movements

Question 9

REM sleep vs slow-wave (deep) sleep> Genital activity>

Answer 9

REM: Penile erection or vaginal secretion
Slow-wave sleep: lack of genital activity

Question 10

REM sleep vs slow-wave (deep) sleep> Dreams>

Answer 10

REM= dreams
slow wave= fewer dreams

Question 11

Zeitgebers=

Answer 11

environmental cues that help entrain circadian rhythms which include our sleep-wake cycles

Question 12

vision as a zeitgeber>

Answer 12

• light from eye? retinal ganglion cells: indictaes it is daytime> triggers our circadian rhythm
• light via RGC also carries info about environment to brain; this:
  >resets inner clock daily
  >provides synchronisation of our circadian clock to solar day (24hrs)
  >can also track seasonal changes & regulates sleep

Question 13

What happens without sunlight zeitgebers?>

Answer 13

• our body clock would shift & we would sleep later & later each night

Question 14

reduction of conditioned systems over time>

Answer 14

• if over time, repeated disappointments/lack of reinforcement of system, this can lead to a reduction in efficacy of system
• if previously reinforced behaviour is not linked to reward, the behaviour will reduce: “extinction” occurs

Question 15

If a particularrly bad experience of a previously POSITIVE CS occurs, what happens?

Answer 15

• impression left on hippocampus
• memory consolidated to long-term declarative memory

Question 16

The gustatory transduction pathway includes>

Answer 16

• tongue & taste receptors
• also uses smell

Question 17

The gustatory transduction pathway: tongue»

Answer 17

contains Papillae which contain taste buds
>each specialises in something: (e.g. salty, sour, bitter)
>each has sensory cells that detect different chemical properties of dood
>sends info> hind brain> thalamus (relay)> taste zone of cortex, which processes taste info & co-ordinates response> rest of body

Question 18

other aspects of hunger monitoring»

Answer 18

• hypothalamus (lateral & ventromedial)
• eyes, mouth, nose
• liver
• stomach & intestines
• adipose tissues

Question 19

Hypothalamus & hunger monitoring>

Answer 19

• lateral hypothalamus= involved in INITATING eating
  >responds to signals from the body (e.g. low blood glucose) to: stimulate, hunger, activate feeding mechanisms, decrease metabolic rate etc
• ventromedial hypothalamus= involved in REGULATING satiety (suppressing feeding behaviour when had enough)