Motivation & Emotion

Question 1

Describe 2 theories of emotion

Answer 1

• James: Brain processes stimuli first, fear is experienced –> then you react
• Cannon: Your body is overwhelmed/ your reace by expression -> this tells brain to fear

Question 2

Discuss the concept of the Limbic system and its importance to emotion noting (Limbic = experience + Expression of emotion / EEE)

Answer 2

• Broca’s Limbic Lobe: ring around corpus callousum:
  
  • Cingulate gyrus
  • Medial surface of temporal lobe
  • Hippocampus
  • Memorise: A single guy (Cingulate gyrus) in a Temporary (temporary lobe) relationship with a Hippo (Hippocampus

Question 3

• The Papez Circuit

Answer 3

• When limbic system talks to the cortex to create emotion, cortex linked with hypothalamus
• Hippocampus = EXPRESSION of emotion (the smile on your face or tears on your eyes)
  
  • Rabies (disease by virus affecting nervous system) can damage hippocampus leading to hyperemotions
• Anterior Thalamus : lesion can cause sundem bouts of laughing or crying…
• Memorise: Cingulate cortex= experience (Guy is THINKING = EXPERIENCE about breakup)
• Hypothalamus = expression
• Loop: cortex (details of various emotion/ processing) info sent to single guy (cingulate cortex) which thinks about the experience and tells the HIPPO travels by river of fornix to reach the hypothalamus (dramatic hyppie which REACTS and is full of EXPRESSION)-> these reacts affect nuclei’s in anterior thalamus -> tells single guy -> tells cortex

Question 4

1. What emotion is mainly linked with the amygdala?

Answer 4

Fear

Question 5

1. Where is information from all sensory systems integrated in the amygdala?

Answer 5

Basolateral nuclei (contributes to emotion and memory)

Question 6

1. What is the pathway for info @ amygdala?

Answer 6

• Ventral amygdalofugal pathway

Question 7

1. What happens when temporal lobectomy takes place?

Answer 7

1. What happens when temporal lobectomy takes place?

• This was experimented on rhesus monkeys
  
  • Led to less fear and anger + vocal/ facial expression fear
• In humans (temporal lobe lesions, esp in amygdala) leads to FLAT emotions (kluver bucy syndrome)

Question 8

1. What can result from a bilateral amygdalectomy ?

Answer 8

• Reduced fear

Question 9

1. What happens when you stimulate the amygdala?

Answer 9

• Increased vigilance + anxiety + fear

Question 10

1. What is the nature of the memories formed by the amygdala?

Answer 10

• emotional or painful events

Question 11

1. What can result from an amygdalotomy?

Answer 11

• Less aggression
• Less anxiety
• Might have bad side effects though

Question 12

1. What other structure besides amygdla is associated with aggression and how is this structure inhibited?

Answer 12

• Hypothalamus (inhibited by telencephalon)
• Mid brain via 2 pathways where hypothalamus talks to brain stem:
  
  • Medial forebrain bundle -> ventral tegemental area = predatory aggression
  • Dorsal longitudinal fasciculus -> periaqueductal gray matter = affective aggression

Question 13

• What is the hypothesis on serotonin deficiency?

Answer 13

Less 5HT= more aggression

Drug PCPA blocked 5HT production found increase in aggression

Question 14

• What is motivation

Answer 14

The force (voluntary movement) which drives behaviour

Question 15

• Which brain structure regulates homeostasis and motivation?

Answer 15

LATERAL Hypothalamus can motivate your body in order to create homeostasis

Question 16

• What are 3 components of neuronal response

Answer 16

• Humoral, visceromotor & somatic motor response

Question 17

• What are the 2 states of energy balance?

Answer 17

Prandial state= anabolism (A= build up= glycogen + triglycerides)

Postabsorptive state= catabolism (C = break down for energy)

Question 18

• What is leptin responsible for?

Answer 18

Regulate your body weight, can lower appetite and increase use of energy

Question 19

• What areas of hypothalamus is affected in anorexia and obesity?

Answer 19

Anorexia= lAteral hypothalamic syndrome

Obesity = VentrOmedial hypothalamic syndrome

Both related to signalling of leptin

Question 20

• Which part of the hypothalamus is responsible for controlling feeding?

Answer 20

Arcuate nucleus of hypothalamus

Question 21

• What happens when elevated leptin occurs?

Answer 21

Arcuate neurons @ hypothalamus (responsible for controlling feeding) which release aMSH and CART peptides are ACTIVATED

• Anorectic peptides makes you less hungry
• Spreads to areas responsible for making humoral, visceromotor and somatic responses: paraventricular nucleus (=humoral response), intermediolateral gray matter of spinal cord, lateral hypothalamus

Question 22

• What do arcuate neurons @ hypothalamus do?

Answer 22

Releases aMSH + CART peptides when high leptin= less appetite

Releases orexigenic peptides- NPY and AgRP when less leptin = increase appetite (activates PNS to stimulate feeding behaviour

Question 23

• What neurons stimulate feeding behaviour and what do they contain?

Answer 23

Neurons @ LH contains Melanin concentrating hormone (MCH) which prolongs consumptions + orexin which talks to cortex and promotes initiation of meal

Question 24

What are the 3 phases of feeding?

Answer 24

• Cephalic, gastric, substraye (neck, stomach, broken down bits)
• Cephalic= hunger when empty stomach, NPY/AgRP in neurons activated, remove ghrelin in cells of stomach that normally stop appetite
• Gastric= Full, CNX / vagus picks up on stomach stretch and tells your brain, works with CCK , Insulin @ B cells in pancreas = anamobolism
• Substrate = highest level of insulin in blood (tells body to build up)

Question 25

How can self motivation be stopped?

Answer 25

* Blockage of DA receptors @ VTA

Question 26

What is the role of DA in motivation?

Answer 26

* DA gives you motivation to eat food, not necessarily affect the hedonistic desire (liking) of food itself

Question 27

During a meal what spike occurs?

Answer 27

* Mood elevation = rise in blood tryptophan + brain 5HT

Question 28

What does the drug dexfenfluramine (Redux) do?

Answer 28

* Increases 5HT, suppress appetite

Question 29

What disorders occur in 5HT regulation?

Answer 29

* Bulimia nervosa, anorexia, both accompanied with depression

Question 30

Which drug is used for Tx of imbalanced 5HT?

Answer 30

* Antidepressants can elevate 5HT (e.g. fluoxetine- Prozac)

Question 31

What pathway triggers thirst?

Answer 31

* Volumetric thirst -\> Hypovolemia = lowered blood vol. * Kidney (blood coming to kidney, uses AII to communicat) + Heart (notices drop in BP, tells vagus) – brain-\>@ subfornical organ * Osmometric thirst -\> hypertonicity = increased solutes in blood * @vasular organ of lamina terminalis, tells lateral hypothalamic areas (vasopressin secreting magnocellular cells) -\> posterior lobe of pituitary -\> blood out

Question 32

What is the role of vasopressin?

Answer 32

* Its an antidiuretic hormone (anti pee), tells kidney to keep water

Question 33

What happens when loss of vasopressin secreting neurons of hypothalamus occur\>

Answer 33

* Diabetes insipidis * Polydipsia and polyuria

Question 34

What is normal temp our cells prefer?

Answer 34

* 37 deg celcius

Question 35

What neurons are responsible for temp homeostasis?

Answer 35

* Neurons @ anterior hypothalamus