Module 11 - Synaptic integration Flashcards
Two types of neural networks
Convergence - Many neurones coming together to transmit information to one neuron (ie a motor neuron)
Divergence - One neuron splitting off in several ways to transmit information to many different neurons (ie a sensory neuron)
EPSP: what is it, what kind of input causes it, what type of polarisation does it cause, and what does it do?
Excitatory postsynaptic potential
Excitatory input
Small depolarisation
Caused by a triggered influx of Ca²⁺, raising the membrane potential and increasing the likelihood of a triggered action potential
IPSP: what is it, what kind of input causes it, what type of polarisation does it cause, and what does it do?
Inhibitory postsynaptic potential
Inhibitory input
Small hyperpolarisation
Caused by a triggered influx of Cl⁻ or K⁺, lowering the membrane potential and increasing the likelihood of a triggered action potential
Summation: what is it and what does it affect?
The combination of postsynaptic potentials
Spatial - How close to the hillock, how many synapses
Temporal - How often are they firing, how many from one synapse
Shunting inhibition
An inhibitory postsynaptic potential closer to the hillock of a synapse which shuts down action potentials from EPSPs further away from the soma of the neuron
Reward pathway
Involves dopamine release
In a standard situation, a tonic (normal) amount of dopamine is released (1-8Hz) but in either a phasic (good) or bad situation, more (15-20Hz) or less (less frequent rate of) dopamine is released
Absolute refractory period
The period in which another action potential cannot be triggered no matter how large the stimulus
Lasts 1-2ms and occurs during depolarisation
Relative refractory period
The period after the absolute refractory period in which another action potential can be triggered but requiring a larger stimulus
Occurs during hyperpolarisation
How do neurons encode information?
Frequency modulation - monitoring the strength and frequency of signals
