Synaptic integration in the CNS Flashcards
What are examples of neurons in the CNS receiveing excitatory and inhibitory input (3)
- DTR/MSR
- Motor control
- Pain modulation
Where are motor neurons located
In the anterior horns of the gray matter
True or False:
A single motor neuron may be innervated by up to 10,000 different presynpatic endings
True
True or False:
The generation of an action potential at the axon hillock depends on the integration of both signals
True
Where does an axosomatic synapse occur
At the cell body (soma)
Where does an axodendritic synapse occur (2)
- Dendritic spine
2. Dentritic shaft
Where does an axo-axonic synapse occur
At the axon
What are the 2 types of synapses
Type I and type II
What do type II synapses tend to be
Inhibitory
What do type I synapses tend to be
Excitatory
What type of synapses has a thicker post synaptic density
Type I
Why do synapses occur at different locations
So we can have presynaptic facilitation of signal
What is back propagation
Generating potentials back to where they were formed
What causes back propagation
Voltage gated Na+ channels
Where is the highest amount of voltage gated Na+ channels
The axon hillock
What is back propagation important for
Learning and memory
How does the back propagation potential look in relation to the action potential
The peak is not as high and it is more spread out
Why does the potential formed by back propagation have a lower peak
We don’t have many voltage gated Na+ channels in the dendrites
Why does the potential go backwards
There is propagation of the potential in both directions
The further away you are from the axon hillock what needs to occur for an action potential to take place
The stimulus needs to be greater
True or False:
A stimulus from the dendrites is able to initiate an action potential that occurs later down the axon
True
What happens to an excitatory synpatic potential as it travels toward the soma
The potential decreases
What is the time constant
How fast the stimulus dissipates
What is the length constant
How far does the stimulus travel before it dissipates
What does temporal summation relate to
The time constant
What does spatial summation relate to
The length constant
What is temporal summation
The process of adding consecutive synaptic potentials together
What is spatial summation
The process of adding presynaptic potentials together from multiple locations on the axon
What happens if something has a long time constant
Stimuli are able to summate leading to an action potential