Electronic signalling and membrane permeability of neurons

Question 1

does varying the conc of EC K+ or Na+ have a difference on resting potential (E) ?

Answer 1

K+ - the resting potential tends towards the Ek which is -83mV

Question 2

What inhibits K+ channels and what inhbits Na+ channels?

Answer 2

TTX for Na

TEA for K

Question 3

What causes IPSP? through which receptors

Answer 3

Cl- through GABAR and GlyR

Question 4

What is the effect of increasing the size fo the stimulus?

Answer 4

Increasing frequency of APs

Question 5

What is the difference between passive electrical flow in axons and active?

Answer 5

Passive due to sub-threshold stimulus: further away from stimulus the smaller the I
Active due to supra-threshold stimulus: no matter how far away from the stimulus, same I

Question 6

What is an example of a symporter?

Answer 6

Na+/K+/Cl- co-transporter

Question 7

Which directions does the Na/K+ atpase move ions?

Answer 7

Na+ out

K+ in

Question 8

What are some of the most common Nav channelopathies?

Answer 8

SCN1A - epilepsy, migraine, autism
SCN2A - epilepsy, autism, episodic ataxia
SCN3A - epilepsy
SCN9A - pain insensitivity or extreme pain disorder

Question 9

What are some of the most common Kv channelopathies?

Answer 9

KCNQ2, KCNQ3 and KCNMA1 - epilepsy

KCNA1 - episodic ataxia type 1

Question 10

What are some of the most common Ca2+ channelopathies?

Answer 10

CACNA1A - episodic ataxia type 2, spinal cerebellar ataxia 6 and familial hemiplegic migraine
CACNA1B - myoclonous-dystonia syndrome
CACNA1F - x-linked congenital stationary night blindness
CACNA1H - childhood absence epilepsy

Question 11

What effects do ouabain and digoxin have?

Answer 11

Block Na/K+ ATPase, increase force of heart contraction by elevating IC Ca2+ due to effects on Na+/Ca2+ exchanger.

Can also cause depression