Neural communication

Question 1

direct measure of neural communication

Answer 1

brain activity in the form of changes in electricity - put a needle inside + outside cell and compare

Question 2

indirect measure of neural communication

Answer 2

they measure things like blood flow and glucose consumption; things related to brain activity

Question 3

why is neural communication chemical

Answer 3

movement of ions into and out of the cell (Na+ and K+)

Question 4

why is neural communication electrical

Answer 4

both Na and K are positively charged; as they move, they change the cell potential

Question 5

why is the inside of the cell more negative (compared to the outside)

Answer 5

pos. ions come in and as they leave the cell, it becomes more negative (only when compared to outside)

Question 6

ion passive transport

Answer 6

diffusion through lipid bilayer & facilitated diffusion (channel)

Question 7

ion active transport

Answer 7

ion pump

Question 8

plasma membrane

Answer 8

keeps proteins, ions out of cell

Question 9

channels

Answer 9

are specific to each protein, only flow according to forces of nature

Question 10

moving molecules against forces of nature requires

Answer 10

energy, through a pump.

Question 11

sodium-potassium pump

Answer 11

pumps sodium out of cell, and potassium into cell. uses 2/3rds of brain’s ATP

Question 12

how many bindings are in a sodium-potassium pump?

Answer 12

3 for Na and 2 for K

Question 13

potassium leak channel

Answer 13

always open, requires no energy. potassium leaves cell

Question 14

how are cells negative

Answer 14

more ions leave the cell than come in; K leaks outside of cell where there’s less

Question 15

where is there more sodium

Answer 15

outside of cell

Question 16

where is there more potassium

Answer 16

inside cell

Question 17

RMP

Answer 17

resting membrane potential

Question 18

resting membrane potential

Answer 18

baseline; balance between chemical and electrical forces

Question 19

what effects can a neurotransmitter have when it binds to a receptor

Answer 19

depolarize or hyperpolarize the membrane

Question 20

depolarize the membrane

Answer 20

makes the cell less negative; EPSP

Question 21

excitatory post-synaptic potential (EPSP)

Answer 21

increase likelihood of action potential

Question 22

hyper-polarize the membrane

Answer 22

makes cell more negative; IPSP

Question 23

inhibitory post-synaptic potential (IPSP)

Answer 23

decrease likelihood of action potential

Question 24

when does an action potential is fired

Answer 24

stimulus causes cell’s voltage to move towards 0 mV; when reaches about -55mV, action potential is triggered

Question 25

PSP is...

Answer 25

graded rapid decremental

Question 26

threshold of excitation

Answer 26

when PSP is enough to open voltage-gated sodium channels and depolarization is large enough that AP is generated;

Question 27

Action potential

Answer 27

massive, brief reversal of membrane potential. they always look the same

Question 28

phases of AP

Answer 28

depolarization, repolarization, hyperpolarization, resting potential

Question 29

depolarization phase

Answer 29

sodium comes into the cell, making it more positive

Question 30

direction of action potential

Answer 30

towards axon terminals

Question 31

repolarization phase

Answer 31

potassium leaves the cell, making it more negative, bringing it to balance

Question 32

hyperpolarization phase

Answer 32

brief moment when too much potassium has left the cell

Question 33

voltage-gated sodium channels

Answer 33

in resting remain closed, but opened by electrical force, allowing sodium to come in

Question 34

voltage-gated potassium channels

Answer 34

in resting remain closed, but slowly opens after threshold of excitation; hyperpolarization happens because of slow closure

Question 35

does AP not decay?

Answer 35

it does, but it is constantly regenerated, so looks the same all way down the axon

Question 36

which part of cell is covered in voltage-gated sodium channels?

Answer 36

axon

Question 37

unmyelinated axons

Answer 37

has Nav channels everywhere

Question 38

number of Nav channels in axon...

Answer 38

dictates conduction speed

Question 39

in the case of too few Nav...

Answer 39

the AP decays

Question 40

why is unmyelinated axons slower?

Answer 40

AP decays faster and there is more need of regeneration

Question 41

Myelination allows for...

Answer 41

less AP decay, more spread out Nav, therefore faster transmission

Question 42

where are the Nav found in myelinated axons

Answer 42

Nodes of Ranvier

Question 43

multiple sclerosis

Answer 43

autoimmune disease; progressive destruction of myelin. all sorts of symptoms occurs, from inability to send out motor signals and receive sensory signals

Question 44

which potential is amplitude modulated?

Answer 44

PSP; stronger signals conveyed by larger PSP

Question 45

which potential is frequency modulated?

Answer 45

AP; stronger signal conveyed by bigger frequency of AP in one measure of time

Question 46

terminal boutons

Answer 46

where axons end

Question 47

vesicles

Answer 47

contained in the bouton, is filled with neurotransmitters

Question 48

vesicles release neurotransmitters when

Answer 48

action potential stimulates it

Question 49

calcium channels

Answer 49

voltage-gated; triggers vesicle and membrane to merge together - contents released in synapse

Question 50

calcium is more prominent...

Answer 50

outside the cell

Question 51

receptors are located in

Answer 51

the dendrite membrane

Question 52

ligand-gated ion channels

Answer 52

receptors that only open/bind to substance when there is a neurotransmitter present

Question 53

receptor types

Answer 53

ionotropic and metabotropic

Question 54

ionotropic receptors

Answer 54

channels; ions cross the membrane

Question 55

metabotropic receptor

Answer 55

signalling proteins;

Question 56

what kind of receptor allows for fast, transient effect

Answer 56

ionotropic

Question 57

what kind of receptor allows for slow, longer lastings effect

Answer 57

metabotropic

Question 58

protein binded to metabotropic receptors

Answer 58

G proteins

Question 59

G-protein coupled receptors (GPCR)

Answer 59

metabotropic

Question 60

G proteins can be

Answer 60

positive (excitatory) or negative (inhibitory) modulatory

Question 61

when neurotransmitters binds to metabotropic receptors...

Answer 61

G proteins break off from receptor and flow inside cell

Question 62

do G proteins cause direct or indirect change in voltage?

Answer 62

indirect; intracellular messenger

Question 63

types of presynaptic receptors

Answer 63

autoreceptors heteroreceptors

Question 64

autoreceptor

Answer 64

inhibitory; bind to same neurotransmitter being released

Question 65

what role does presynaptic receptors play in maintaining brain activity balanced?

Answer 65

autoreceptors have a feedback role, to track how active the axon is

Question 66

heteroreceptor

Answer 66

both excitatory and inhibitory; bind to different neurotransmitter being released

Question 67

3 ways neurotransmitter clean up happens

Answer 67

diffusion enzymatic degradation re-uptake

Question 68

metabolites

Answer 68

components of neurotransmitters, broken down by enzymes

Question 69

drug types

Answer 69

agonist & antagonist

Question 70

what determines the effect that the neurotransmitter has?

Answer 70

the receptors they bind to! wether they're gonna be positive or negative modulatory