Week 123 - Depression Flashcards
What is the main excitatory neurotransmitter in the CNS?
Glutamine
What does ‘excitatory’ neurotransmitter mean?
It means that an action potential is more likely to be fired by the neurotransmitter binding to its receptor.
What does ‘inhibitory’ neurotransmitter mean?
It means that an action potential is less likely to be fired by the neurotransmitter binding to its receptor.
‘Inhibitory’ and ‘Excitatory’ are ways to describe neurotransmitters, which are they most useful to describe?
Those that act on ionotropic neurotransmitters. Mostly for Glutamine and GABA, as other neurotransmitters tend to be more complicated.
Which type of receptors does glutamine bind to?
Both ionotropic and metabotropic.
What is the basic effect of prolonged activation of glutamine receptors?
Hyperexcitability, seizures.
Name two substances that block glutamine receptors and thus cause sedation.
Alcohol and ketamine.
What is the main ‘inhibitory’ neurotransmitter of the CNS?
GABA - Gamma-amino butyric acid
What are the two types of receptor for GABA?
- GABAa - Ionotropic (Cl-), fast inhibition
* GABAb - Metabotropic, presynaptic inhibition of GABA release.
What occurs when you activate GABAa receptors?
Sedation
What class of drugs activates the GABAa receptors and what effect does this have?
Benzodiazepines, sedation.
How does the date rape drug work?
It is a mixture of Benzodiazepines that activate GABAa receptors causing sedation, combine this with alcohol blocking glutamine receptors causing further sedation.
What occurs when GABAa receptors are blocked?
Hyperexcitability > seizures.
What is the name for the ‘other’ cells in the nervous system?
Glia
Glia is the name for a group of other cells in the nervous system, what are there functions?
- Astrocytes - Support cells + damage repair
- Oligodendrocytes - Myelination of CNS
- Microlagia - Macrophrages of the nervous system.
- Ependymal cells - Produce CSF.
- ALSO, important for synthesis of both glutamate and GABA.
Aside from GABA what is the other major inhibitory neurotransmitter of the central nervous system?
Glycine, but it’s boring.
What are receptor type does Glycine have?
Ionotropic.
What six functions is serotonin implicated in?
1) Depression
2) Apetite control
3) Nausea
4) Sleep
5) Sexual function
6) Analgesia
Name three drugs from the GEM-F that use serotonin as a target.
- SSRIs - Fluoxetine
- SNRIs - Tramadol
- Ondansetron
What are the five parts in the life of neurotransmitter that can be used as a drug target?
1) Receptors
2) Transporters
3) Affects
4) Breakdown enzymes
5) Sources of variation
Out of the five parts in the life of a neurotransmitter what do SSRIs target for serotonin?
Transporters.
What is serotonin also known as?
5-hydroxytrptamine
What does an excess of serotonin cause in the GI system?
Diarrhoea and nausea.
What are the four main conditions that causes disorder in the dopaminergic system?
1) Parkinson’s - Causes the death of neurones in the substantia nigra (which is one location for synthesis of dopamine)
2) Schizophrenia
3) Drug addiction
4) Tourette’s
Which cells in the periphery produce histamine?
Mast cells.
What are the three major types of opioids?
1) Endorphins
2) Enkephalins
3) Dynorphins
What type of opioids means ‘morphine like’?
1) Endorphins
What are the functions of endorphins?
- Analgesics
* Reward and motivation
Give three examples of endorphins.
1) Morphine
2) Codeine
3) Tramadol
What are the 5 core symptoms of depression?
1) Depressed mood
2) Tiredness after very little effort
3) Loss of interest
4) Reduced energy
5) Lasts more than 2 weeks
What classes a ‘depressed mood’ in the core symptoms of depression?
- Diurnal variation
- Varies very little from day to day
- Unresponsive to circumstances
What is mild depression?
• 2 core symptoms and two others
What is moderate depression?
• 2 core symptoms and three or four others.
What is severe depression?
• All core symptoms are severe and four others.
What are the four main classes of antidepressants?
- Trycylcic antidepressants
- SSRIs (Selective serotonin reuptake inhibitors)
- Monoamine oxidase inhibitors
- ‘Others’ - SNRIs and receptor blockers.
Which tricyclic antidepressant should NOT be prescribed?
Dosulepin
What is the first line choice for antidepressants?
Citalopram - SSRI
Which antidepressant should be first line treatment for those who have had cardiac disease/MI?
Sertraline as it does not prolong QT interval as citalopram does.
The risk of withdrawal symptoms are most likely to occur in which SSRI?
Paroxetine
Which antidepressant is most likely to be associated with death by overdose?
Venflaxine
