Motivation

Question 1

What is motivation?

Answer 1

Driving force, physical need and wanting or liking something

Question 2

What is motivation controlled by?

Answer 2

Hypothalamus

Question 3

What is the prandial state?

Answer 3

Full/ eating state when anabolism happens

Question 4

What is anabolism?

Answer 4

Food breakdown

Question 5

What is catabolism?

Answer 5

Breakdown of food stores

Question 6

What is the postabsorbtive state?

Answer 6

Fasting state when catabolism happens

Question 7

What is parabiosis?

Answer 7

Sharing of blood circulation between animals

Question 8

What is the effect of parabiosis on body weight in ob/ob mice?

Answer 8

Blood bourne signals are shared about the hypothalamus (so a genetically obese mouse would loose weight)

Question 9

What happens following a fat-rich meal?

Answer 9

Adipose tissues produce leptin which signals to the Arcuate nucleus to tell you to stop eating

Question 10

What do mice show if they’ve got a lesion in the ventromedial hypothalamus?

Answer 10

Increase in food intake and body weight

Question 11

What does lateral hypothalamic syndrome cause?

Answer 11

Diminished appetite for food = anorexia

Question 12

What does ventromedial hypothalamic syndrome cause?

Answer 12

Overeating and obesity

Question 13

What are lateral and ventromedial hypothalamic syndromes both associated with?

Answer 13

Related to leptin signalling

Question 14

What is the anorexic response?

Answer 14

Elevated leptin levels sensed by specialised cell bodies in the Arcuate nucleus that release alpha MSH and CART

Question 15

What does CART stand for?

Answer 15

Cocaine and amphetamine regulated transcript

Question 16

What does alpha MSH and CART project to?

Answer 16

Lateral hypothalamus, paraventricular nucleus, spinal cord and preganglionic neurons of sympathetic autonomic NS

Question 17

What do alpha MSH and CART do in the lateral hypothalamus?

Answer 17

Inhibit feeding behaviour

Question 18

What do alpha MSH and CART do in the paraventricular nucleus?

Answer 18

Induce CRH and TRH

Question 19

What is an orexigenic response?

Answer 19

Response to decreased leptin levels

Question 20

What happens when decreased leptin levels are sensed?

Answer 20

Arcuate nucleus releases NPY and AgRP

Question 21

What do NPY and AgRP project to?

Answer 21

Lateral hypothalamic area and paraventricular nucleus

Question 22

What do NPY and AgRP do in the lateral hypothalamic area?

Answer 22

Stimulates feeding behaviour

Question 23

What do NPY and AgRP do in the paraventricular nucleus?

Answer 23

Inhibits secretion of hypophysiotropic hormones controlling ACTH and TSH

Question 24

What do the LH neurons stimulating feeding behaviour contain?

Answer 24

Melanin-concentrating hormone (MCH) and orexin

Question 25

What does MCH do?

Answer 25

Prolongs consumption

Question 26

What does orexin do?

Answer 26

Promotes meal initiation and related to narcolepsy and addiction behaviour

Question 27

What are the three phases in the satiety cascade?

Answer 27

Cephalic, gastric and substrate (intestinal)

Question 28

What happens in the cephalic phase?

Answer 28

Ghrelin released when the stomach is empty | Activated NPY/AgRP containing neurons in the Arcuate nucleus

Question 29

What can doctors do to cause a loss of appetite?

Answer 29

Removal of the ghrelin-secreting cells of the stomach

Question 30

What happens in the substrate (intestinal) phase?

Answer 30

Gastric distension signals to the brain via the vagus nerve | Works with CCK released in the intestines in response to foods

Question 31

Why do we eat?

Answer 31

``` Hedonic (liking food) Drive reduction (Wanting food) ```

Question 32

Which facet of eating are the dopaminergic systems involved in?

Answer 32

Wanting/craving

Question 33

What is the reward system?

Answer 33

Dopaminergic projections from the ventral tegmental area to the nucleus accumbens where dopamine gets released

Question 34

How do drugs of abuse hijack the reward system?

Answer 34

Causing extensive and disproportionate release of dopamine

Question 35

What are the stages of the addiction cycle?

Answer 35

``` Acute reinforcement/social drug taking Escalating/compulsive use Dependence Withdrawal Protracted withdrawal Recovery ```

Question 36

What is dependant drug use driven by?

Answer 36

Need to stop withdrawal symptoms

Question 37

What happens in obese people that binge eat?

Answer 37

Downregulation of D2 receptors so they get less reward

Question 38

What are the key neural circuits of reinforcement?

Answer 38

Hippocampus involved in the memory of reward and the amygdalas involved in the emotional connection

Question 39

What is microdialysis?

Answer 39

Measuring neurotransmitter release in vivo

Question 40

What is dopamine release in the nucleus accumbens correlated with?

Answer 40

Motivation and the anticipation of reward

Question 41

How are mood and food connected?

Answer 41

Serotonin in hypothalamus rises in anticipation of food and spike during a meal