Biopsychology- Synaptic Transmission Flashcards
(14 cards)
Why is synaptic transmission?
The process by which neighbouring neurons communicate with each other by sending chemical messages across the synaptic cleft that separate them.
The process of the synaptic transmission?
1)An electrical impulse travels down a Presynaptic neuron, along the axon, to the terminal branches.
2) when the electrical impulse gets to the terminal branches it stimulates the synaptic vesicles.
3)The neurotransmitters are released from the synaptic vesicles and travel across the synaptic cleft (gap). This is when the electrical impulse has been changed into a chemical impulse.
4) the neurotransmitters cross the synaptic cleft to get to the dendrite of the postsynaptic neuron.
5) there are receptors on the denture of the postsynaptic neuron. The receptors are known as the LOCK 🔐
6) if the neurotransmitter is the correct shape 🔑 than it can fit into the receptors on the dendrites.
7) the connection between receptors and neurotransmitters can cause an electrical impulse to be created in the dendrites.
This depends on whether the neurotransmitters are excitatory or inhibitory.
8) excitatory means it more likely that an electrical impulse will travel down the post synaptic neuron and the process will begin all over again
Inhibitory means it is less likely that an impulse will travel down the post synaptic neuron
9) the neurotransmitters doesn’t fit into the receptors means that no electrical impulse will be created in the postsynaptic neuron.
10) once the neurotransmitter has been released from the postsynaptic receptor site (or doesn’t fit) reuptake happens. The neurotransmitter is taken back up to the presynaptic where it is stored in the synaptic vesicle and made available for later release ♻️.
What happens if the neurotransmitter doesn’t fit the receptor?
Reuptake happens
What is the communication called when the info passed chemically between neurons can only be passed in one direction?
Uni-directional
Why can information it only be chemically passed in one directions?
1)Diffusion
2) synaptic verticals are only in the presynaptic neuron
3) receptors are only found in the postsynaptic neuron
What is summation?
For a new electrical action to form the postsynaptic cell, the electrical charge needs to pass a threshold
Effect off all E and I neurotransmitters influence on the postsynaptic cell. They are summed up.
What is the eff t if an excitation neurotransmitter?
Increases the likelihood of a neuron firing
What is the effect of an inhibition neurotransmitter?
It decreases the likelihood of a neuron firing
Why do excitatory neurotransmitters cause excitation of the postsynaptic neurons?
By increasing its positive charge and making it more likely to fire.
This occurs because sodium ions (➕) channels in the membrane if the dendrites in the postsynaptic neuron open, allowing sodium to enter. Sodium brings it positive charge making neuron more positive depolarising it.
Why do inhibitory neurotransmitters cause inhibition in The post synaptic neuron?
The neuron becomes enticing charged and less likely to fire. This occurs because chloride ion channels (➖) bring its negative charge into the cell causing the neuron to become more negative, hyperpolarising it.
How is the electrical impulse created?
The action potential of the postsynaptic neuron Is only triggered if the sum of the E and I signals are any one tune reaches the threshold. If this occurs an electrical impulse is created and travels down the axon if the presynaptic neuron.
What two impacts do drugs have on synaptic transmission?
1) I ctraing the amount of neurotransmitters in the synaptic cleft by blocking the reuptake channels.
2) decreasing the around of neurotransmitters influence the synaptic cleft by blocking the receptors
What is SSRIs and how does it work?
It is a treatment for OCD and blocks the reuptake channels so serotonin remains in the synapse and can continue to blind with more receptors. This is because too little serotonin is thought to cause OCD
What is antipsychotic and how does it work?
It is a drug for schizophrenia treatment. It blocks the receptor to prevent dopamine blinding. This is because too much dopamine is thought to cause schizophrenia
