Biopsychology: topic 3 ‘the process of synaptic transmission’ Flashcards
what is synaptic transmission?
- the process for transmitting messages from neuron to neuron
- it involves the conversion of electrical signals to chemical signal
what creates an action potential in the pre-synaptic neuron?
- an electrical signal that travels from the dendrites down the axon to the presynaptic terminal
- all signals within the neuron are electrical.
what is the tiny gap between neurons called? what does it do?
- synapse
- separates each neuron from the next
what happens to the electrical signal when it reaches the synapse? why? how does it do this?
- it must become chemical
- electrical signals cannot travel across the synapse
- to do this it stimulates vesicles (sacs containing neurotransmitters - chemical messengers) to release the neurotransmitters into the synapse
what do vesicles contain that are released into the synapse?
- neurotransmitters (chemical messengers)
what do neurotransmitters bind to after crossing the synapse? where does this occur?
- receptors on the postsynaptic neuron
- this occurs on the dendrites of the next neuron
what determines the effect of the neurotransmitter on the postsynaptic neuron?
- whether the neurotransmitter is excitatory or inhibitory, this affects how the signal/information is transmitted
what is the process called when neurotransmitters travel back to the presynaptic neuron? what does this process do?
- reuptake, this process allows neurotransmitters to be stored and recycled
fill in the blank: the sacs that contain neurotransmitters are called _______
- vesicles
true or false: the electrical signal can directly travel across the synapse
- false, the electrical signal must convert to a chemical signal to cross the synapse
what are neurotransmitters? how are neurotransmitters structured?
- chemical messengers in the brain that fit into post-synaptic receptor sites
- neurotransmitters have specific structures that function like a lock and key
what is the role of acetylcholine? (ACh)
- causes muscles to contract at the junction of motor neurons and muscles
how does dopamine affect the nervous system?
- influences emotional arousal, pleasure, and voluntary movement
- dopamine is crucial for mood regulation and motor control
what effect do neurotransmitters have on neighbouring neurons?
- they can have either an excitatory or inhibitory effect
- this determines whether the receiving neuron will fire or not
what is an inhibitory synapse? what is an example of a neurotransmitter that causes inhibition?
- a synapse that makes the receiving neuron less likely to fire
- serotonin is an example of a neurotransmitter that causes inhibition
what is an excitatory synapse? what is an example of a neurotransmitter that causes excitation?
- a synapse that increases the likelihood of the post-synaptic neuron firing
- adrenaline is an example of a neurotransmitter that causes excitation
how do excitatory and inhibitory potentials compare to vehicle controls?
- excitatory potential is like the accelerator; inhibitory potential is like the brake
- this analogy helps understand their opposing functions
what is summation in the context of neuron firing?
- the process of adding up excitatory and inhibitory synaptic inputs
- this determines the overall likelihood of the neuron firing
if the net effect on the post-synaptic neuron is inhibitory, what happens? when does this occur?
- the neuron will be less likely to fire
- this occurs when inhibitory neurotransmitters dominate
if more excitatory neurotransmitters bind with receptors, what is the effect?
- the neuron is more likely to fire
- a positive net effect results in increased firing likelihood
if more inhibitory neurotransmitters bind with receptors, what is the effect?
- the neuron is less likely to fire
- a negative net effect results in decreased firing likelihood
