antidepressants

Question 1

Describe the symptoms of clinical depression

Answer 1

• low mood
• appetite changes
• sleep disruption
• difficulty concentrating

Question 2

different classifications of clinical depression

Answer 2

• unipolar depression
• bipolar disorder

Question 3

neural pathways implicated in depression

Answer 3

• noradrenergic pathway
  
  • NA regulates sensory processing and arousal
  • deficiency in pathway → depression
• serotonergic pathway
  
  • regulates limbic processing and wakefulness
  • inhibitory receptors e.g 5H1A inhibit release of NT and AP firing
• neurotrophins
  
  • post synaptic neurone = releases BDNF acting on pre-synaptic neurone to stabilise connection
  • depression = reduced activity = synapse loss

Question 4

various theories regarding the causation of depression

Answer 4

brain regions
epigenetic changes
stressful events
neurotransmitters

Question 5

brain regions associated with depression

Answer 5

• cingulate nucleus
• nucleus circumbance
  
  • dopamine increase in depression = increased secretion of BDNF
• amygdala overstimulation
• hippocampus
  
  • decreased levels of BDNF and high cortisol

Question 6

neurotransmitters associated with depression

Answer 6

• noradrenaline
• serotonin
  
  • long term trophic effects on synapse strength
• glutamate
  
  • overactivation of NMDA receptor causes neurodegeneration
• BDNF
  
  • less produced due to changes in neuroarchitecture

Question 7

evidence for monoamine hypothesis

Answer 7

• iproniazid
  
  • first antidepressant = MOA I
• reserpine
  
  • causes depression and parkinsons, depletes stores of MOA transmitters
  • depletes vesicles of MA neurotransmitters
• tricyclic ADs
  
  • inhibit re-uptake of serotonin and noradrenaline

Question 8

Describe animal models used to study anti-depressants

Answer 8

• acute stress models = AD efficacy
  
  • rats placed in water container twice
  • second time, AD drugs increase escape behaviour
• chronic stress models
  
  • mild electric shock on feet of rats
  • develop learned helplessness

Question 9

Identify the protein targets of antidepressant drugs

Answer 9

monoamino oxidase inhibitors - enzyme
tricyclic antidepressants - transporters
selective serotonin reuptake inhibitors - transporters

Question 10

describe the mechanism of action of MOI

Answer 10

• inhibit type A MOAs
• reduces degredation of monoamines = more in cleft = increased 5HT

Question 11

describe the mechanism of action of tricyclic antidepressants

Answer 11

inhibit neuronal reuptake of 5HT and NA

Question 12

describe the mechanism of action of MOI