Lecture 9 - Neuronal diversity + dendritic processing

Question 1

in the equation for voltage attenuation in different cables (dendrites) what does x stand for? what does lambda stand for?

Answer 1

x = distance
lambda = space constant

Question 2

which 2 things determine the space constant in the equation for voltage attenuation?

Answer 2

resistance, diamater

Question 3

if a neuron has a higher resistance (i.e has more myelin), the charge is kept in the structure better. therefore, what happens to the exponential curve?

Answer 3

shortens

Question 4

explain what is meant by voltage attenuation in regards to dendrites? what shape does the curve make on the graph? what about open ended cables?

Answer 4

you begin with a large voltage, some leaks out giving an exponential curve - open ended cables collapse quicker as charge will just seep/flow out at the end

Question 5

the electrotronic distance is the same as the rise time of an …..

Answer 5

EPSP

Question 6

low impedence structures have ….. decrease in voltage as they go from being ….. to …..

Answer 6

small, large, smaller

Question 7

high impedence structures have ….. decreases in voltage as they go from being …. to …..

Answer 7

large, smaller, large

Question 8

if you have a low impedence next to a high impedence structure, what is it called?

Answer 8

impedence mismatch

Question 9

two excitatory inputs onto different dendrites is called what?

Answer 9

local shunting - sublinear

Question 10

inhibitory and excitatory synapses on different dendrites is called what?

Answer 10

additional shunting

Question 11

dendritic …… affects the flow of charge

Answer 11

shape

Question 12

active conductances can give rise to ……. summation, where the timing of events is critical

Answer 12

supralinear