Lecture 4

Question 1

Ohms Law

Answer 1

Ina= gn(vm-em)

Question 2

Initialy for small depolarizations peak gna is very small.

Answer 2

DF is large, product Ina is small

Question 3

For larger depolarizations to peak gna rises faster than

Answer 3

DF falls, product Ina is larger

Question 4

For even larger depolarizations peak gna now reaches a maximum constant so the product Ina is now completely dependent on

Answer 4

falling DF so Ina gets smaller until depolarizing Ena=Ina=0

Question 5

For depolarizing to Vms more positive than Ena, ________________ to rise again but is reversed

Answer 5

the product Ina starts

Question 6

_______________ the relative conductance of the Na+ channels to various ions

Answer 6

selectivity filter

Question 7

Li is not a substrate of Na+ and K+ pumps so it accumulates in the cell permanently displacing an equivalent amount of K+ . The reduction in the K gradient results in

Answer 7

a lower Vm until the cell becomes inexcitable. The therapeutic action of small doses of LiCl2 administered to manic depressive patients may be thee result of small modifications in nerve cell excitability

Question 8

____________________ Is an example of how evolution does no necessarily see,ect for the perfect solution to problem but rather for one that provides a selective advantage however small

Answer 8

The high permeability of the Na+ channel to Li+

Question 9

Experiment #3:

Answer 9

so far, two way to isolate currents change V com or the ionic concentrations

Question 10

_____________ selesctiivly blocks voltage dependent Na channels from the japanese puffer fish

Answer 10

TTX tentrodoxin

Question 11

__________________ selectively blocks voltage dependent K+ channels synthetic

Answer 11

Tea tetraethyl ammonium

Question 12

What is the sequence of events during a synaptic transmission

Answer 12

• depolarization AP enters the presynaptic terminal
• voltage dependent Ca2+ channels open and Ca2+ ENTERS the presynaptic
• Ca causes synaptic vesicles to migrate the presynaptic membrane
• vesciles dock, lyse-> quintal release of NT into the synaptic cleft (vesicles carry 104 moles of NT)
• NT passively diffuses down its concentration gradient to the post synaptic membrane
• NT binds with specific receptor proteins, the Nt receptor complex undergoes a conformational change which results in an increase in gna in the postsynaptic membrane Ina toward depolarization of the postsynaptic cells
• when depolarization exceeds threshold AP is generated post synaptically -0terminal of NT action
• STorage of Nt presyanptice of vesicles

Question 13

________ neurotransmitter found in vertebrates at the neuromuscular junction and ganglia of the autonomic nervous system

Answer 13

acetylcholine

Question 14

_____________ in the basal forebrain contains cells that produce high concentrations of CHAT. Thus these cells have a high probability of being cholinergic

Answer 14

nucleus of basalts meynert

Question 15

It is interesting that patients who die from alzeheimers disease or how suffered from dementia have __________________

Answer 15

60-90% less chat activity in their cortices than age matched controls

Question 16

As a result t__________ has become an important focus for alzheimers research

Answer 16

NBM

Question 17

_____________ blocks ACh release. produced by an anaerobic bacterium. which uses a virus to produce the toxin

Answer 17

botulinum toxin

Question 18

___________is a common name for various plant extract alkaloid arrow poisons from central and South America . It competitively and reversibly binds to NACHr and has high affinity for nAChR than does ACh . The principle source of this molecule is from two plants

Answer 18

curare

Question 19

________________ binds irreversibly to nAChR found in thee salivary glands of Many banded (formosan) krait: can be radioactively labeled for autoradiography experiments and use to quantify the nACHr density

Answer 19

alpha bungarotoxin

Question 20

__________ blocks acetylcholine esterase (Ache) thus blocking Achg hydrolysis and thus proteentioating the effect of Ach hydrolysis antiesteerases

Answer 20

antiesteerases

Question 21

__________ catalyzes the uptake of Chloe,aceetate is returned to the bloodstream. Heemeicholineium is an example of a synthetic permeate inhibitor, blocks choline reuptake preventing subsequent ACH synthesis

Answer 21

hemicholinium

Question 22

_____________________ catalyzes the synthesis of ACH

Answer 22

Choline acetyl transferase

Question 23

________________ is an example of a synthetic CHAT inhibitor that prevents ACh synthesis

Answer 23

CHioline acetyl transferase

Question 24

___________ is an example of a synthetic Chat inhibitor that prevents synthesis

Answer 24

styrylpyridiine

Question 25

_______________ a drug or toxin that blocks the normal action of a protein or a biochemical process

Answer 25

inhibitor

Question 26

An example of an inhibitor that interferes with synaptic transmission at the eNMJ by inhibiting the enzyme AChE is__________________

Answer 26

physostigmine

Question 27

the term ___________________ refers specifically to the action of substances on receptors sand are often called receptor agonists and receptor antagonists. A receptor agonist blinds to receptor and mimics the action of a naturally occurring neurotranmitter

Answer 27

antagonist or agonists

Question 28

A receptor antagonist also binds to a receptor but blocks the action of the _____________

Answer 28

neurotransmitter

Question 29

There are two types of neurotransmitters

Answer 29

iionotrophic and metabotrophic

Question 30

_________________ are directly associtateted with ion channels. Neurotransmitters binding to an ionotropic receptor causes a direct change in ion movements across the post synaptic membrane

Answer 30

ionotrophic receptors

Question 31

the nicotinic acetylcholine receptor is an ____________________

Answer 31

inotropic receptor

Question 32

____________ induction changes in the post synaptic cell that can lead secondarily to changes in the state of ion channels

Answer 32

metabolic receptors

Question 33

___________ response mediated by metabotropic receptors are generally slower and longer lasting than those induced by iomnotropjic receptors

Answer 33

postsynaptic cells

Question 34

___________ initiate and in gtraceellular signaling process that can result in the opening or closing of ion channels

Answer 34

metabotrophic receptors

Question 35

________ are G proteins coupled receptors

Answer 35

metabotrophic receptors

Question 36

___________________________ mediated by metabotropic receptors are generally slower and longer lasting than those induced by ionotrophic receptors

Answer 36

postsynaptic cell responses

Question 37

___________ initiate an intracellular signaling process that can result in the opening or closing of ion channels

Answer 37

metabotropic receptors

Question 38

Metabotropic receptors are ________________________

Answer 38

G protein coupled rreceptors

Question 39

_______________ receptor to muscarine; blocked by atrophine. These ligand-gated receptors are found where synaptic actions are slower and more subject to metabolic factors

Answer 39

muscarinic acetylcholine recepters