Neuroscience Chapter 3 And 4

Front 1

Patch clamp method

Back 1

micropipet seals off a single ion channel

pipet attached to amp chemical signal then changed to electircal signal and read by amp

Front 2

Voltage gated sodium and potassium channels in response to action potential

Back 2

Resting Membrane potential both are closed

At depolarization:
sodium voltage gate opens sodium enters in
potassium voltage sensor is slow and remains closed

Then after prolonged depolarization:
sodium channel inactivates
potassium voltage gate opens potassium flows out repolarizing the cell

once repolarized they are both closed and inactivation gate on sodium is open d again

Front 3

Tetradioxin

Back 3

obstructs sodium channel preventing flow

Front 4

Saxotoxin

Back 4

obstructs sodium channel preventing flow

Front 5

A toxins

Back 5

slow inactivation of sodium channels: prolonging action potential

Front 6

beta toxins

Back 6

shift voltage dependence of sodium channels : causing voltage gates to open at more negative voltages: resulting in random action potential fireing

Front 7

Dendrotoxin

Back 7

blocks potassium channel
no toxin is known to alter ability to open voltage gate

Front 8

ion channel genes

Back 8

10 different SCN sodium channel genes
10 different CANA calcium channel genes
100 different types of potassium channel genes

Front 9

Ligand gated ion channels

Back 9

can be less selective than voltage gated
can be located on surface membrane or organelle

Front 10

Types of channels

Back 10

ligand gated
voltage gated
heat actiabeda
stretch activated - reflex

Front 11

components of sodium (Na+) and calcium (Ca2+) channels

Back 11

contain six membrane spanning regions repeated 4 times

can have accessory proteins (beta subunits) that regulate chanel

on sodium and calcium channels inactivation gate beteen region 3 and 4

Front 12

components of potassium channel

Back 12

membrane spanning regions typically in packs of sixes but can be different numbers

4 of these units compose the ion channel

Front 13

voltage sensor componenet

Back 13

is membrane spanning unit next to T unit

Front 14

How potassium channel works

Back 14

selectivity filter is negatively charged therefore it attracks positive ions