Neurotransmitters Flashcards
What is a synapse?
The junction between neurones and other neurones, or between neurones and their effector cells
What is a neurotransmitter?
A chemical that diffuses from the pre-synaptic membrane to the post synaptic membrane that is released from a synapse
What happens when an action potential arrives at the synapse?
It causes voltage gated calcium channels to open
The influx of calcium ions into the presynaptic neurone causes what to happen?
Vesicles containing neurotransmitter fuse with the pre-synaptic membrane (exocytosis) and the neurotransmitter is released into the synaptic cleft
One released into the synaptic cleft what happens to the neurotransmitter?
It acts on the post synaptic membrane and causes an action potential which propagates along the post synaptic neurone
In the neurone what is a major therapeutic target?
Blocking the influx of calcium ions
What are the 3 types of calcium channel?
- L-type = long acting
- T-type = transient, open more briefly
- N-type = neither long or transient
Once an action potential in the post synaptic neurone has been propagated which next step is essential?
Enzyme breakdown and reuptake into the pre-synaptic neurone
What is acetylcholine broken down into so it can be recycled in the pre-synaptic terminal?
Acetate and choline
Give some examples of monoamine neurotransmitters
- Noradrenaline
- Dopamine
- Adrenaline
- Serotonin
Which drug blocks monoamines from being up taken into the presynaptic neurone?
Fluoxetine
What is the role of tricyclic drugs?
Anti-depressants - act through monoamine oxidase transporters
Monoamines act under which part of the NS?
The sympathetic NS - flight or fight
What are the effects of fluoxetine on serotonin levels?
Decreased serotonin uptake -> causing increased serotonin -> decreased aggression
What is the brains primary excitatory neurotransmitter?
Glutamate
