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MD2- Neuroscience Block > Transmitters and Receptors > Flashcards

Flashcards in Transmitters and Receptors Deck (20):
1

in order to effect the CNS, drugs must be able to cross the [....]. after which they may be go on to modulate NT synthesis, [....], release, [....], or receptor.

BBB

inactivation (reuptake, metabolism), storage

2

a depolarization event and Calcium++ release cause the release of NA into the synaptic space. From here it is either metabolized by [...] on the prejunctional membrane, go through reuptake channels to be metabolized by intracellular [....], bind [.....] receptors on the postjunctional membrane, and/or undergo postjunctional reuptake via postjunctional channels.

alpha receptors

MAO

alpha/beta NA

3

cocaine blocks neuronal [....], causing NA to become [.....].

reuptake of NA

depleted

4

how is phenytoin optimized to be optimally active only during epileptic fits?

phenytoin decreases excitatory fibre activity, decreases glutamate release on post synaptic motor nerve fibre by inhibiting Na+ channels, but only when the sodium channel is open (during an epileptic event).

5

as a Tx for epilepsy, benzodiazapines act to enhance inhibitory [...] NT activity, thereby inhibiting motor nerve stimulation.

GABA

6

what NT's are targeted in drugs treating sedation & anxiety? Associated receptors?

GABA --> GABA A ligand-gated receptor.

Histamine is targeted to produce sedation in paediatric patients via H1 receptor anatagonists.

7

what NT's are targeted in drugs treating anxiety? Associated receptors?

Serotonin targeted on CNS pre-junctional receptors.

Noradrenaline to treat peripheral tachycardia.

Neuropeptide Y --> NPY1 receptor reduces anxiety

8

beta-adrenoreceptor antagonists block the physical signs of [....] (sweating, tremor, tachycardia), however they have little effect on the [....], or the root cause of the problem.

anxiety

CNS

9

clinically recognized anxiety disorders are: generalized anxiety states, [....], [...], and post-traumatic stress disorder.

They can be treated with anxiolytics, but these also have the effect of causing [...] and [...].

panic disorder
phobia

drowsiness
sedation.

10

Anxiolytic agents are:
1. benzodiazepines - treating anxiety states and insomnia.

2. non benzodiazepines - [.....] antagonists, treat peripheral symptoms of anxiety

3. [......]

beta adrenoreceptor

barbiturates - used in controlled settings only as anticonvulsants/anaesthesia. too toxic for general anxiety

11

benzodiazepines have a [...] therapeutic index.
they act to reduce [....] and anxiety, elicit sedation and [....], and obliterate [....]

wide.
muscle tone.
induction of sleep.
memory.

12

GABA is the main inhibitor NT in the CNS. It has two type of receptors:
1. GABA [...] receptors are [....] channels
2. GABA [...] receptors are [.....] receptors.

Benzodiazepines only interact with the [...] receptor only, and act to increase the receptors affinity for [.....].

GABA A - ligand gated ion
GABA B- G-protein coupled

GABA A
GABA

13

Benzodiazepines only interact with the [...] receptor, and act to increase the receptors affinity for [.....] by binding to an [...] site. In this sense, they are [....] modulators.

This increases the frequency of [.....], without changing the [.....].
NB: This effectively increases the sensitivity of the channel without increasing the maximum response.

GABA A
GABA
orthosteric site.
orthosteric.

the GABA A Cl- channel opening.
mean conductance or channel open time

14

As opposed to benzodiazepines, the barbiturates bind the GABA receptor and act to [....], increasing the sensitivity AND maximum response of the channel.

prolong channel opening time.


-->Barbiturates will kill you! Benzo's won't!

15

short-acting benzodiazepines are [....] and [...]. These are ideal for use as [....].

They cause no daytime [...] and safe for use in the elderly and drivers.

Disadvantages?

oxazepam and temazepam.
hypnotics.(tx insomnia)

anxiety.

Disadvantages:
As an anxiolytic they are slow-onset and require fine dosing control, 3-4 doses per day is required.

16

long-acting benzodiazepines such as [...] and [...] are ideal for use as [....].

they are [....] onset, convenient daily dosing, and act to decrease [...].

disadvantage?

diazepam and clonazepam.
anxiolytics.

fast.
muscle tension/spasms.

dis:
may cause daytime anxiety when used as a hypnotic


17

contrast pharmacological efficacy vs clinical efficacy

pharm:
strength of the receptor activation (ie. full vs partial agonist)

clinical:
strength of the benefial effect

18

where efficacy refers to a drugs ability to produce a maximum effect, and potency refers to the amount of a drug required to produce an effect of given intensity:

1. barbiturates increase the [....] of GABA
2. benzodiazepines increase the [...] of GABA

barbs-->efficacy

benzo's -->potency.

19

non-benzodiazepine hypnotics are: [....].

they bind the [....] site of the [....] receptor, express little anticonvulsant activity, and have a [...] half life.

zolpidem and zopiclone

benzodiazepene of GABA receptor.
short.

20

non-benzodiazepine anxiolytics is: [...].

acts as a partial agonist at [....] receptors.
They show little dependance but have a [...] onset.

buspirone

5HT^1A receptors
slow