Ch. 13: Intro to CNS (Vickroy)

Question 1

tranquilizer

Answer 1

produces a calming effect at low doses and sedation at higher doses. Patient is relaxed, reluctant to move, awake, and unconcerned with surroundings (.e. ace, diazepam)

Question 2

sedative

Answer 2

depresses most behaviors and diminishes excitability WITHOUT producing sleep. Patient can be aroused with sufficient stimuli (i.e. phenobarb, xylazine)

Question 3

hypnotic

Answer 3

produces strong behavioral depression and promotes state of light sleep from which the animal can be aroused

Question 4

Narcotic

Answer 4

produces a deeper state of sleep from which an animal CANNOT be easily aroused (i.e. morphine)

Question 5

anesthetic**

Answer 5

produces deep sleep with a loss of sensation. (ex. halothane, ketamine, propofol)

Question 6

For nearly all classes of CNS depressants, the level of CNS depression is dose-dependent and synergistic with other CNS depressants**

Answer 6

:)

Question 7

Can you achieve anesthesia with benzodiazepines?

Answer 7

No (very difficult)

Question 8

4 main excitatory CNS transmitters

Answer 8

Ach, DA, NE/EP

Question 9

3 main inhibitory CNS transmitters

Answer 9

Adenosine (Ado), GABA, serotonin (5-HT)

Question 10

Rank CNS stimulants in increasing order of CNS activity

Answer 10

analeptics < pscychomotor stimulants < convulsants

Question 11

Rank CNS depressants in increasing order of CNS activity

Answer 11

anesthetics < narcotics < hypnotics < sedatives < tranquilizers

Question 12

T/F: Benzos do not produce analgesia*

Answer 12

T

Question 13

2 distinct pathways to depress CNS function**

Answer 13

1) antagonism of excitatory NT glutamate (via blockage of NMDA receptors)
2) agonism of inhibitory NT GABA (by enhancing GABA receptors)

Question 14

What drug uses antagonism of excitatory NT glutamate via blockage of NMDA receptors as its pathway to depress CNS function?

Answer 14

ketamine

Question 15

Is ketamine a barbiturate-type agent?

Answer 15

no

Question 16

parenteral

Answer 16

Administered by some means other than oral or rectal intake, particularly intravenously or by injection.

Question 17

How does diazepam work?*

Answer 17

enhances actions of the inhibitory NT GABA on GABA receptors, which opens Cl channels, makes cell less excitable, and thereby depresses CNS function

Question 18

Why is ketamine commonly coupled with diazepam?

Answer 18

synergistic effect for more adequate CNS depression. Allows you to use drugs at lower doses to reach desired effect and avoid negative side effects

Question 19

Elements of BBB that stop drugs from passing

Answer 19

• very tight junctions in cerebral blood vessels
• pinocytotic vessels to capture drugs that do manage to diffuse across endothelial cells
• astrocytic foot processes surround capillaries

Question 20

Does phenylephrine normally cross BBB?

Answer 20

No

Question 21

T/F: drugs w/n the same therapeutic group can exhibit marked differences in their abilities to cross the BBB

Answer 21

T

Question 22

T/F: disease patterns or genetic dysfuction can affect BBB permeability

Answer 22

T (i.e. hypertonic solutions, ivermectins in collies, encephalitis)

Question 23

ivermectins in collies

Answer 23

can cross BBB because they lack normal MDR-1 gene that codes for P-glycoprotein, which carries drugs back across BBB that leaked through

Question 24

glutamate is pro-stimulatory or pro-inhibitory?

Answer 24

pro-stimulatory. Blocked by ketamine.

Question 25

serotonergic agents primarily used for:

Answer 25

tx of behavioral disorders

Question 26

6 CNS monoamines

Answer 26

- Ach - EP - NE - DA (only one that acts almost entirely within CNS) - histamine - serotonin

Question 27

4 rep. examples of amino acids & derivates

Answer 27

- aspartate - glycine - GABA* - glutamate*

Question 28

6 rep. ex. of neuropeptides

Answer 28

- ACTH - endorphins - somatostatin - aldosterone - enkephalins - TRH

Question 29

Do monoamines cross BBB?

Answer 29

NO

Question 30

What does DA control?

Answer 30

motor function, sleep/wake cycle. It is a catecholamine like NE,EP

Question 31

Primary elim. of Ach

Answer 31

AChE

Question 32

Primary elim. of DA, EP, NE

Answer 32

Catecholamine (CA) uptake, monoamine oxidases (MAO)

Question 33

primary elim. of serotonin

Answer 33

serotonin (5-HT) transporters, MAO

Question 34

biosynthetic precursor of DA, NE, EP

Answer 34

tyrosine

Question 35

biosynthetic precursor of serotonin

Answer 35

tryptophan

Question 36

How do synthesis, release, and elim. mechs. of monoamines in the CNS compare to in the periphery?

Answer 36

identical

Question 37

CNS catecholamines are excitatory/inhibitory for most brain functions

Answer 37

excitatory

Question 38

are dopamine receptors abundant or scarce?

Answer 38

abundant

Question 39

drugs that inhibit CNS CA fx tend to stimulate/depress CNS fx

Answer 39

depress

Question 40

Acepromazine mech.

Answer 40

DA antagonist. Produces CNS depression (sedative/tranquilizer)

Question 41

xylazine mech.

Answer 41

alpha-2 agonist. Sedative/analgesic

Question 42

how do alpha-2 agonists depress CNS?*

Answer 42

alpha-2 receptors on presynaptic neurons sense when there is too much NE (which is stimulatory) and shut down NE release. Alpha-2 agonists encourage this process so that NE is released even less, resulting in net CNS depression

Question 43

Name 6 alpha-2 agonists

Answer 43

``` xylazine detomidine medetomidine dexmedetomidine romifidine clonidine ```

Question 44

serotonin functions

Answer 44

regulations of mood, appetite, sleep/wake cycles, sensory perception.etc

Question 45

T/F: there are a lot of different 5-HT receptors

Answer 45

T

Question 46

why don't use serotonergic agents with MAO inhibitors?

Answer 46

may produce serotonin syndrome that can lead to coma and death

Question 47

major inhibitory aa transmitter in the CNS*

Answer 47

GABA

Question 48

What kind of drugs mimic or enhance GABA function?

Answer 48

barbiturates, benzos, propofol

Question 49

Major excitatory aa transmitters of CNS?

Answer 49

glutamate and aspartate.