Basic Principles of neuropharmacology - Ch. 12

Question 1

neuropharmacology

Answer 1

study of drugs that can alter processes controlled by the nervous system - either PNS or CNS, most agents act by altering the synaptic transmission (more selective), only a few alter axonal conduction

Question 2

Axonal conduction

Answer 2

process of conducting an action potential down the axon of the neuron

Question 3

synaptic transmission

Answer 3

process by which information is carried across the gap between the neuron and the postsynaptic cell, requires the release of neurotransmitter molecules from the axon terminal followed by binding of these molecules to receptors on the postsynaptic cell

Question 4

transmitter-receptor binding

Answer 4

series of events is initiated in the postsynaptic cell, leading to a change in its behavior, ex. if postsynaptic cell is a neuron it may increase or decrease firing rate, if it is a muscle cell, it may relax or contract

Question 5

axonal conduction - only local anesthetics

Answer 5

not very selective, a drug that alters axonal conduction will affect conduction in all nerves. ex. local anesthetics decrease axonal conduction

Question 6

synaptic conduction - most neuropharmacologic drugs

Answer 6

highly selective because synapses are different from each other, synapses at different sites use different transmitters, most transmitters employ more than 1 type of receptor

Question 7

the ability of a neuron to influence the behavior of another cell

Answer 7

depends upon the ability of that neuron to alter receptor activity on the target cell

Question 8

neurons alter receptor activity by

Answer 8

releasing transmitter molecules which diffuse across the synaptic gap and bind to receptors on the postsynaptic cell

Question 9

Steps in synaptic transmission

Answer 9

1. synthesis of transmitter from precursor molecules
2. storage of transmitter in vesicles
3. release of transmitter in response to action potential, vesicles fuse with the terminal membrane and discharge their contents into synaptic gap
4. action at receptor - transmitter binds to receptor on the postsynaptic cell causing a response in that cell
5. termination of transmission, transmitter dissociates from its receptor and removed from synaptic gap

Question 10

neuropharmacologic drug works by

Answer 10

influencing receptor activity on target cells

Question 11

synaptic transmission - step 1

Answer 11

transmitter synthesis - molecules of transmission must be present in the nerve terminal, AKA transmitter synthesis from precursor molecules

Question 12

synaptic transmission - step 2

Answer 12

transmitter storage - once the transmitter is synthesized, it must be stored until the time of its release, stored within vesicles in axon terminal

Question 13

synaptic transmission - step 3

Answer 13

transmitter release - release of transmitter triggered by the arrival of an action potential at the axon terminal

Question 14

synaptic transmission - step 4

Answer 14

receptor binding - following release, transmitter molecules diffuse across the synaptic gap and undergo reversible binding to receptors on the postsynaptic gap, initiates events that result in altered behavior of postsynaptic cell

Question 15

synaptic transmission - step 5

Answer 15

termination of transmission - dissociation of the transmitter from receptors, then removal of free transmitter from synaptic gap - removed either by reuptake, enzymatic degradation or diffusion

Question 16

transmitter synthesis - increased

Answer 16

storage vesicles will contain transmitters in abnormally high amounts, thus when an action potential reaches the axon terminal more transmitters will be released thus more transmitters will be available to receptors on the postsynaptic cell, causing activation of those receptors to increase

Question 17

agonists - bind directly at receptors

Answer 17

drugs that directly activate receptors

Question 18

antagonists- bind directly at receptors

Answer 18

prevent receptor activation

Question 19

two ways neurons elicit responses

Answer 19

1. axonal conduction

2. synaptic transmission

Question 20

Axonal conduction

Answer 20

not selective

Question 21

synaptic transmission

Answer 21

highly selective, differ from eachother

Question 22

receptors

Answer 22

alter receptor activity on the target cell

Question 23

steps in synaptic transmission

Answer 23

1. synthesis
2. storage
3. release- initiated by action potential
4. binding - transmitter molecules released into transmitter gap - bind to receptor sites - this is reversible
5. termination - removal by reuptake, enzyme degradation and diffusion

Question 24

Drugs effects on synaptic transmission

-transmitter synthesis

Answer 24

increase, decrease

cause synthesis of super transmitters - modified and increase activation of receptors

Question 25

Drugs effects on synaptic transmission

-transmitter storage

Answer 25

• disruption of storage - fewer transmitters available

- receptor activation is decreased

Question 26

Drugs effects on synaptic transmission

-transmitter release

Answer 26

promote of inhibiting release

Question 27

Drugs effects on synaptic transmission

-receptor binding

Answer 27

• cause receptor activation
• block receptor activation
• enhance receptor activation

Question 28

Drugs effects on synaptic transmission

-termination of transmission

Answer 28

• block transmitter reuptake - block enzymes

- inhibit transmitter degradation

Question 29

Selectivity

Answer 29

second most desirable to effective - able to alter a disease process while leaving other physiologic processes largely unaffected