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
