Synaptic Transmission

Question 1

What are the types of synapses?

Answer 1

electrical and chemical

Question 2

this type of synapse has gap junctions between neurons

Answer 2

eletrical

Question 3

electrical synapse main protein

Answer 3

connexins

Question 4

this type of synapse has a narrow intercellular gap

Answer 4

electrical

Question 5

in what direction do electrical synpases occur

Answer 5

both direction

Question 6

which type of synapse has a synaptic delay

Answer 6

chemical

Question 7

in what direction do chemical synapses occur

Answer 7

one direction

Question 8

Charcot marie tooth is csused by a mutation in one of the _____ genes expressed in the Schwann cells disease:

Answer 8

connexin

Question 9

what type of synapse does CMT disease occur in

Answer 9

electrical - ionic gap junctions

Question 10

charcot marie tooth symptoms:

Answer 10

impaired myelination
peripheral - motor and sensory
foot drop
not fatal

Question 11

sequence of events at chemical synpase

Answer 11

AP - calcium enters - transmitter release - binds to receptor - open close ion channels

Question 12

what is Ca2+ buffering?

Answer 12

Ca2+ accumulates in presynaptic terminal

Question 13

proteins involved in vesicle docking:

Answer 13

SNARE:
syntaxin
SNAP-25
synaptobrevin

Question 14

targets nicotinic cholinergic terminals at NMJ

Answer 14

botox

Question 15

targets glycinergic inhibitory terminals

Answer 15

Ttx

Question 16

what is synaptotagmin?

Answer 16

calcium sensor

Question 17

specific protease that cleaves SNARE proteins associated with the vesicular and presynaptic cell membranes

Answer 17

botulinum and tetanus

Question 18

this toxin occurs after open wounds and takes up inhibitory spinal interneurons

Answer 18

tetanus

Question 19

this toxin affects motor nuerons

Answer 19

botulinum

Question 20

what proteins are involved in vesicle recycling?

Answer 20

clathrin and dynamin

Question 21

what is synaptic fatigue?

Answer 21

synaptic depression -prolonged stimulation of synapse decreasing # of vesicles

Question 22

inward current of transmitters causes

Answer 22

depolarization - excitatory

Question 23

outward current of transmitters causes

Answer 23

hyperpolarization - inhibitory

Question 24

how can transmitter be removed by synaptic cleft?

Answer 24

diffusion, uptake or enzymatic degradation

Question 25

what is enzymatic degradation

Answer 25

Ach hydrolysed by acetylcholinesterase

Question 26

what does the NMJ release

Answer 26

Ach - nicotinic Ach receptor

Question 27

what are postsynaptic potentials

Answer 27

graded potentials - size decreases

Question 28

Muscle weakness due to reduced functional ACh receptor be a symptom of

Answer 28

Myasthenia gravis

Question 29

Myastenia gravis symptoms

Answer 29

droopy eyelids, limb muscles weakness

Question 30

MG treatment

Answer 30

inhibitory acetylcholinesterase and removal of thymus

Question 31

disease associated with carcinoma of the lung and reduced Ach release

Answer 31

Lambert-eaton

Question 32

what does lamber eaton syndrome do to channels

Answer 32

produces antibody against voltage gated calcium channels

Question 33

what are the postsynaptic receptor types

Answer 33

1. ion gatted channels 2. g-protein coupled receptors

Question 34

Neuromuscular junction receptor

Answer 34

nicotinic acetylcholine receptor

Question 35

Permeable to cations (mostly Na+, K+, small amounts of Ca2+). Not as selective as the voltage gated channels

Answer 35

nicotinic Ach receptors

Question 36

Prolonged exposure to ACh causes

Answer 36

desensitization (inactivation) of Ach receptor

Question 37

high doses of Ach can cause

Answer 37

muscle paralysis

Question 38

carries most of the excitatory current through the ACh receptor ion channel

Answer 38

Na+

Question 39

Individual ligand gated receptor channels can be studied with

Answer 39

psthc clamp recording opened in ach presence

Question 40

ionotropic glutamate receptors have two major classes:

Answer 40

AMPA and NMDA

Question 41

synthetic drug agonist * Most common receptor in the CNS

Answer 41

AMPA

Question 42

permeable to Na and K

Answer 42

AMPA

Question 43

permeable to Na and Ca

Answer 43

NMDA

Question 44

which receptors are dually regulated

Answer 44

NMDA glutamate receptors

Question 45

depolarization of NMDA removes which blocking channel

Answer 45

Mg2+ ion blocking channel

Question 46

receptor important in learning and memory formation

Answer 46

NMDA

Question 47

glutamate toxicity is:

Answer 47

Excessive Ca2+ or glutamate entry can be harmful to neurons

Question 48

glutamate toxicity causes:

Answer 48

strokes, epileptic seizures, neurodegenerative diseases like Huntingtons chorea and ALS

Question 49

inhibitory transmitter in spinal interneurons

Answer 49

glycine

Question 50

major inhibitory transmitter in brain

Answer 50

GABA

Question 51

inward flow of Cl- ions

Answer 51

Cl- permeability caused by inhibitory transmitters

Question 52

Which drugs can bind to GABA receptors and increase their inhibitory function

Answer 52

Benzodiazepines Barbiturates

Question 53

prescribes for anxiety

Answer 53

valium and librium

Question 54

Proteins with 7 transmembrane regions activate:

Answer 54

G-protein receptors

Question 55

Most transmitters use _____ coupled receptors

Answer 55

G-protein

Question 56

Examples of G-protein transmitters

Answer 56

serotonin, dopamine, norepinephrine, histamine

Question 57

Synapse of multiple sites for pharmacologic intervention

Answer 57

seronotin synapse

Question 58

which is the serotonin channel

Answer 58

5-HT3