Neurotransmitters Flashcards
What is the main excitatory neurotransmitter of the CNS?
Glutamate
What is the main inhibitory neurotransmitter of the CNS?
Gamma aminobutyric acid (GABA)
Which receptors does glutamate bind to?
Both ionotropic and metabotropic receptors
What does prolonged activation of glutamate receptors lead to?
Hyperexcitability
- i.e. seizures, excitotoxicity, stroke
What happens if you block glutamate receptors?
Sedation
Which drugs can block glutamate receptors?
Ketamine
Alcohol
What is monosodium glutamate?
Excitatory neurotransmitter for the tongue
What are the types of GABA receptors?
GABAa
- ionotropic, conduct Cl-
- Fast inhibition
- effect potentiated by +ve allosteric modulators
GABAb
- metabotropic
- presynaptic inhibition of GABA release
What occurs when GABA receptors are activated?
general principle => sedation
Give examples of drugs which activate GABA receptors?
Benzodiazepines
Alcohol
What occurs if GABA receptors are blocked?
Hyperexcitability => seizures
What is date rape drug?
Combination of alcohol and benzodiazepines
What are glia?
The connective tissue in the nervous system consisting of different types of cell related to neurones
Give examples of some glial cells?
Astrocytes
Oligodendrocytes
Microglia
Ependymal cells
What are astrocytes?
Support cells
- protoplasmic = neuronal support
- fibrous = damage repair
What are oligodendrocytes?
Myelinating cells in CNS
What are microglia?
Macrophages of the nervous system
What are ependymal cells?
Epithelial cells linking ventricles and produce CSF
Why is glia important?
For synthesis of GABA and Glutamate
Mopping up excess neurotransmitter
What is Glycine?
Another major inhibitory neurotransmitter
- conduct Cl- just like GABA receptors
Where in the CNS is glycine mostly active?
Brainstem and spinal cord
Which drug blocks glycine?
Strychnine
Where are serotonin containing neurones found mainly?
Midline raphe nuclei
Which drugs activate serotonin targets?
LSD
Sumatriptan (migraine treatment)
Which drugs block serotonin targets?
Ondansteron (anti-emetic)
Clozapine
Which drugs inhibit serotonin transporters?
SSRIs
Which receptor does sumatriptan activate?
5-HT 1b
Which receptor does Ondansteron block?
5-HT 3
Where is the majority of serotonin kept outside the CNS?
Enterchromaffin cells
Where is ACh made?
Basal forebrain
Brainstem tegmentum
Where is dopamine synthesised?
By neurones of ventral midbrain
- substantia nigra: movement control
- ventral tegmental area: reward, novelty, motivation
Which drugs target dopamine?
All drugs of abuse => increase dopamine abdundance
Parkinson treatment Ropinirole => increase abundance
Antipsychotic: block dopamine receptors
- Haloperidol
- Quetiapine
