Week 3.8 - LIF

Question 1

How is the brain stochastic?

Answer 1

Stochasticity is present across all levels of brain activity. At the neuronal level, synaptic transmission is mediated by the stochastic release of neurotransmitters. Additionally, membrane potentials fluctuate due to the stochastic opening and closing of ion channels.

Question 2

What is the “recipe” for a Poisson signal?

Answer 2

(1) Determine a rate of random events
(2) Take an interval to spread them on
(3) Break the interval into small pieces
(5) If rand() < prob, fire

Question 3

What is a synapse in an integrate and fire model?

Answer 3

Only a tiny voltage flick

Question 4

When are the neurons well-modeled by the Poisson process?

Answer 4

When the source of input to the neurons is unknown.

Question 5

What is an advantage of leaky integrate and fire models?

Answer 5

They are good linear encoders

They are especially good at modeling pyramidal cells.

Question 6

What are some of the problems of leaky integrate and fire models?

Answer 6

(1) No threshold adaptation
(2) No adaptive firing
(3) No resonant spiking
(4) No burst spiking
(5) No subthreshold oscillations
(6) No hyperpolarization spikes

Question 7

In a supercritical Andronof-Hopf bifurcation, the limit cycle___

Answer 7

varies in amplitude

Question 8

The supercritical Andronov-Hopf bifurcation is different from the subcritical Andronov-Hopf bifurcation in that it _______ an unstable limit cycle.

Answer 8

___does not have___