Neurons, neurotransmitters and neuromodulators (2C) Flashcards
What is the neural synapse?
The region that includes the axon terminals of the presynaptic neuron, the synaptic gaps and the dendrites of the post synaptic neuron.
What is the presynaptic neuron?
The neuron that releases neurochemicals into the neural synapse.
What are axon terminals (or axon buttons)?
The end of a neuron (presynaptic) that releases neurochemicals into the neural synapse.
What is the synaptic gap?
The space between the presynaptic neuron and the postsynaptic neuron.
What is the postsynaptic neuron?
The neuron that receives neurochemicals from the neural synapse.
What is the dendrite?
A branched extension of a neuron (post synaptic) on which receptor sites are located.
What is a receptor site in relation to neurons?
A protein molecule on the dendrites of a neuron that receives neurochemicals.
What is a neurochemical?
A chemical substance that transmits neural information within the nervous system.
What is synaptic transmission?
The chemical conveyance of neural information between two neurons across a neural synapse.
What is the first step in synaptic transmission?
Neurochemicals are produced in the axon terminals of the presynaptic neuron.
What is the second step in synaptic transmission?
Hint- it is after neurochemicals are produced.
Neurochemicals are released from the axon terminals into the synaptic gap.
What is the third step in synaptic transmission?
Hint- it is after neurochemicals are released into the synaptic gap.
Neurochemicals bind to receptor sites on the dendrites of the postsynaptic neuron.
What are neurotransmitters?
Chemical molecules that have an effect on one or two postsynaptic neurons. They enables rapid communication and are two types, either excitatory or inhibitory.
What is action potential?
An electrical impulse that travels down the axon of a neuron.
What is the fourth step in synaptic transmission?
Hint- it is after neurochemicals bind to receptor sites.
Neurochemicals affect the postsynaptic neuron, either triggering or inhibiting a response.
What is an excitatory affect?
When the neurotransmitter increases the likelihood of the postsynaptic neuron firing an action potential.
What is glutamate?
The main excitatory neurotransmitter in the nervous system.
What does glutamate do?
It increases the likelihood of the postsynaptic neuron firing an action potential.
What role(s) in functioning does glutamate have?
It has a role in learning and memory by strengthening synaptic connections.
It also have a role in thought and movement.
What is an inhibitory effect?
When the neurotransmitter decreases the likelihood of the postsynaptic neuron firing an action potential.
What is GABA? (gamma-aminobutyric acid)
The main inhibitory neurotransmitter in the nervous system.
What effect does gaba have?
It decreases the likelihood of the postsynaptic neuron firing an action potential.
What role in functioning does gaba have?
Gamma-aminobutyric acid.
It is the main inhibitory neurotransmitter in the nervous system.
It has a role in regulating the postsynaptic activation and prevents overexcitation of neurons. GABA can reduce anxiety and also seizures.
What is a neuromodulator?
A chemical molecule that has an effect on multiple postsynaptic neurons. Is longer lasting, but taking longer to activate.
What is dopamine?
A neuromodulator responsible for voluntary motor movement, the experience of please and reward based learning.(which can sometimes lead to addiction)
Where do the pathways originate from that dopamine travels along?
It is produced in the substantia nigra and ventral tegmental area which are both located in the midbrain.
What affect does dopamine have on the postsynaptic neuron?
It can have either an excitatory or inhibitory effect depending on the type of receptor sites.
What roles in functioning does dopamine have?
A role in coordingating voluntary motor movement and smooth, coordinated muscle movement.
A role in reward based learning.
Role in motivation which can lead to addiction.
What is serotonin?
A neuromodulator primarily responsible for the regulation of mood and sleep.
Where do the pathways originate that serotonin travels along?
The raphe nuclei which are masses of neurons in the brainstem that produce serotonin.
What effect does serotonin have on the postsynaptic neuron?
It has inhibitory effects.
What roles in functioning does serotonin have?
Mood regulation and stabilisation, low levels can result in depression.
Regulates the sleep wake cycle.
Other roles depending on the receptor site and the brain area.
