ELM11: Synaptic integration Flashcards
What is convergence?
When several neurons come together
Motor neurons
What is divergence?
When one neuron splits off
Pain receptors
How does excitatory input determine a response?
Excitatory postsynaptic potential
Small depolarisation
How does an inhibitory input cause a response?
Inhibitory postsynaptic potential
Small hyperpolarisation
How does inhibitory and excitatory input elicit a response together?
Work together
If EPSP-IPSP is over threshold
When an excitatory and inhibitory input act together how is it determined whether an action potential will be fired or not? (factors)
Net sign of combined input
Strength of synaptic input
Location
Firing frequency
What are the two types of summation?
Spatial and temporal
What is spatial summation?
Postsynaptic potentials from multiple synapses
What is temporal summation?
Multiple post synaptic potentials from a single synapse
Frequency of firing
What is cable theory?
Voltage decays from the starting point
How does cable theory link to spatial summation?
PSPs travel to initial segment and attenuate as they go down the neuron
Closer to the initial segment has more influence
How does post synaptic temporal summation work?
PSPs are additive here
New action potentials arrive before the last decays they add on
How does pre-synaptic temporal summation work?
More calcium gathers in presynaptic neuron when there’s more action potentials
More NT released and larger action potential
What occurs in inhibitory neurons when there is both an EPSP and IPSP?
Shunting inhibition EPSP cancelled out
Travels down dendrite and causes influx of chloride
Chloride ions move through GABAA receptors which cancels EPSP
How do neurons encode information?
Convert from AM to FM signals
