Synaptic Transmission Flashcards
(10 cards)
What is a synapse
- gap between two adjacent neurons
- chemical signals sent from presynaptic to postsynaptic
What’s a neurotransmitter?
- Chemical messengers released by neurons
- stimulating or inhibiting development of an action potential in other postsynaptic neurons
What’s the process of Synaptic Transmission?
- Action potential travels along the axon and arrives at axon terminal of presynaptic neuron
- Triggers vesicles to bind and fuse with presynaptic membrane and release neurotransmitters
- These chemicals diffuse across synaptic cleft and bind to receptors on dendrites of postsynaptic neuron
- Binding stimulates postsynaptic neuron to transmit action potential of electrical charge reaches threshold (-60V)
- Neurotransmitters released from receptors and reabsorbed in presynaptic neuron or metabolised
What are Excitatory neurotransmitters
- increase likelihood of new action potential firing
- make electrical charge in cell more positive
What are inhibitory neurotransmitters
Decrease likelihood of new action potential firing
Make electrical charge in cell more negative
What is summation
- Combined effect of all Excitatory and inhibitory neurotransmitters influences on post synaptic neuron
- if threshold reached new action potential fires/forms
What are two types of summation
Temporal summation - combined effects of inputs over time
Spatial summation - combined effect of inputs across multiple neurons
How is Synaptic Transmission Uni directional
Information passed chemically between neurons can only be passed in one direction
What happens to neurotransmitters after detaching from receptors
Transport proteins reabsorb neurotransmitters back into presynaptic neuron (reuptake)
What the role of SSRIs in synaptic transmission
- drug that influences process of neurotransmitters
- block reabsorption of serotonin into the presynaptic neuron
