L2 Synaptic transmission and drugs Flashcards
Name the two types of messages transmitted by synaptic connections.
inhibitory and excitatory
What is Synaptic Transmission?
At the synapse a chemical (neurotransmitter) is released from one neuron, which passes across a small gap, to another neuron.
What is the gap in synaptic transmission called?
Synaptic cleft.
What are the chemical sacks called?
Synaptic vesicles
What is the process of neurotransmitter release called?
Exocytosis
What happens during exocytosis?
Synaptic vesicles fuse with the pre-synaptic membrane and release the neurotransmitter (chemical) to the synaptic cleft. The NT then attach/fuse to the post-synaptic receptors on the receiving neuron.
This can cause sodium channels to open and sodium to enter the neuron thus increasing the potential for it to reach the threshold of excitation and fire.
What ion channels are opened when the action potential travels down down the axon and gets the the pre-synaptic terminal?
Ca+ (calcium) channels.
When the AP reaches the pre-synaptic terminal what attaches to synaptic vesicles causing them to fuse and release the neurotransmitter?
calcium
What is needed for activation of the neurotransmitter?
calcium
What do neurotransmitters attach to on the post-synaptic membrane?
Receptors
What are receptors on the post-synaptic membrane?
membrane proteins which open ion channels.
What 2 ways are involved in neurotransmitter deactivation
Re-uptake (e.g. Dopamine, 5HT - seratonin)
Broken down
e.g. Acetylcholine becomes
Acetyl and Choline
What are the key, lock and door?
NT, binding site, channel
What are the 2 main classes of receptor for the brain?
Ionotropic and metabotropic receptors
What are the 2 main differences between ionotropic and metabotropic receptors?
- the ionotropic receptor binding channel and receptor are all in one structure – therefore, this can occur quickly as it all happens at once.
- Metabotropic receptor is separate from the channel so needs a second messenger system. Slower than ionotropic.