L2. ionotropic and metabotropic channels

Question 1

what are ionotropic channels

Answer 1

receptors where it responds to ligand binding by opening up the pore for ion influc

Question 2

where are ionotropic channels found

Answer 2

NMJ

Question 3

eg of iono R

Answer 3

ACh nicotinic Rs

Question 4

what are excitatory neuronal synapses

Answer 4

generates EPSP

Question 5

what NT does sensory fibers release in stretch reflex

Answer 5

Gglutamate

Question 6

what Nt does interneurons release in a reflex

Answer 6

GABA

Question 7

what Nt does motor neurons release

Answer 7

ACh

Question 8

2 types of Glu iono receptors

Answer 8

NMDA

NON NMDA

Question 9

features of both NMDA and non NMDA

Answer 9

-both cation channels and have GLu open up the channel

Question 10

properties of NMDA channels only

Answer 10

permeable to Ca - important for signalling

- channel blocked by Mg ion so Glu cant bind

Question 11

what are meta R

Answer 11

membrane receptor that initiates a number of metabolic steps to modulate cell activity

Question 12

structure of meta R

Answer 12

7 transmembrane alpha helicases structure

Question 13

what activates meta R

Answer 13

NTs

Question 14

what is coupled tp meta R

Answer 14

g proteins

Question 15

is there ion channel with meta R

Answer 15

no

Question 16

is it slow or fast response in meta r

Answer 16

slow

Question 17

what effects does meta r have

Answer 17

indirect effects on channels and receptors

Question 18

what NTs can bind to meta r and what are the effects

Answer 18

glu - memory, anxiety
ach - regulates EPSP in gangelions
serotonin
dopamine - motor control

Question 19

what happens to cAMP signals when Gi coupled r is activated

Answer 19

• reduces the signal

- inhibitory receptor

Question 20

what happens to cAMP signals when Gs coupled r is activated

Answer 20

increase signal

-stimulatory receptor

Question 21

hat happens to cAMP signals when Gq coupled r is activated

Answer 21

increase s IP3 and DAG levels and signals

Question 22

two modes of action of meta r

Answer 22

indirect and direct

Question 23

what does indirect mode do

Answer 23

act via second messenger like cAMP, PKA

Question 24

what does direct mode do

Answer 24

-activates G proteins and its subunits interacts with target channels

Question 25

three sites of action of meta r

Answer 25

presynaptic, postsynaptic and cell body

- to produce an AP

Question 26

what happens to AP size in the cell body in regards to meta r

Answer 26

the meta R activation closes K channel

- less repolarisation so the AP becomes bigger

Question 27

whats the length of EPSP in nicotininc r

Answer 27

fast EPSP to mediate Na influx

Question 28

whats the length of EPSP in muscarinic r

Answer 28

slow epsp for few secs