neurobiology of emotions

Question 1

What structures make up the limbic system?

Answer 1

• hippocampus
• amygdala
• hypothalamus
• cingulate gyrus
• Basal ganglia

Question 2

What is the function of the hippocampus?

Answer 2

episodic memories are sorted and transferred to long term memory

• links memories to senses
• spatial orientation
• centre neurogenesis

Question 3

What is the function of the amygdala?

Answer 3

• regulates emotional reactions
• creates new memories
• attaches emotion to memories
• activates flight + fight
• fear learning

Question 4

What is the neurological function of hypothalamus?

Answer 4

• control sexual drive and behaviour

- gathers info from other areas with receptive stimuli to regulate stress response

Question 5

What is the function of the cingulate gyrus?

Answer 5

• monitors response to unpleasant stimuli

- fear, fear and avoidance of neg stimuli

Question 6

What is the function of the basal ganglia?

Answer 6

• controls voluntary movements
• reward and reinforced behaviours
• addiction and habit formation

Question 7

What can happen when amygdala is damaged?

Answer 7

• increased aggression
• loss of emotional control
• difficult to recognise emotions

Question 8

What can happen when cingulate gyrus is damaged?

Answer 8

• lack of anxiety
• diminished pain
• improper emotions

Question 9

What is the function of GABA?

Answer 9

• predominant inhibitory neurotransmitter
• regulatory role in amygdala & prefrontal cortex
• enhanced GABA action will reduce anxiety
• site of action of alcohol

Question 10

What are the main excitatory and inhibitory neurotransmitters?

Answer 10

inhibitory - GABA (calms body down after threat)

Excitatory - Glutamate (increases stress response after threat)

Question 11

What is the function of glutamate?

Answer 11

• involved in all aspects of brain function
• uses NMDA, AMPA and KA receptors
• in anxiety disorders will have an imbalance of GABA and glutamate (inc glut)
• also has role in developing psychosis

Question 12

What is the function of serotonin?

Answer 12

• mood and emotion
• sleep
• cognition
• appetite
• memory
• perception

Question 13

What is the function of dopamine?

Answer 13

• pleasure and reward
• attention
• motivation
• emotion
• motor function

Question 14

What is the function of noradrenaline?

Answer 14

• concentration
• attention
• motivation
• energy

Question 15

How does the brain normally react in response to a threat?

Answer 15

initiates two pathways

1) amygdala comes into high alert makes us anxious
- can trigger hypothalamus inc breathing + HR
2) prefrontal cortex analyses situation going on, decided whether response is necessary, can either inc or calm down body response

Question 16

What is pathophysiology of PTSD?

Answer 16

• traumatic memories stored in hippocampus
• activate amygdalas threat response
• don’t need stimulus

Question 17

What are the monoamines?

Answer 17

• serotonin
• noradrenaline
• dopamine

Question 18

What neurotransmitters are involved in depression?

Answer 18

• possibly all monoamines

- serotonin is usually the one targeted by anti-depressants

Question 19

Where are the receptors for serotonin?

Answer 19

• brain
• gut
• platelets

Question 20

Where is serotonin made?

Answer 20

Raphe Nuclei

Question 21

How are monoamines regulates?

Answer 21

auto regulated by themselves and the other monoamines

Question 22

What is the role of dopamine in psychosis?

Answer 22

• excessive dopamine
• so medication reduces levels by blocking all pathways
• unsure how creates psychosis
• can be due to dopamines controlling attention and importance
• excess can cause tendency for irrelevant stimuli to be attributed motivational importance

Question 23

What are the pathways of dopamine?

Answer 23

1) nigrostriatal (pathway faulty in Parkinsons)
2) mesolimbic (involved in psychosis)
3) mesocortical (involved in psychosis)
4) tuberoinfundibulnar

Question 24

What are the positive and negative symptoms of schizophrenia?

Answer 24

positive - hallucinations

negative - decline in cognition

Question 25

How does stress affect monoamines?

Answer 25

• stress represses BDNF
• results in reduced serotonin
• can inc noradrenaline and dopamine initially in response to stress but chronically reduces them if stress continues

Question 26

What is BDNF?

Answer 26

Brain-derived Neurotrophic Factor (keeps neurones healthy and maintains monoamines)

Question 27

What can reduced BDNF cause?

Answer 27

atrophy and apoptosis of hippocampus and prefrontal cortex

- dysfunction of hippocampus and amygdala can cause elevated glucocorticoids (can cause high BP and chronically high HR)