Synaptic transmission Lec 8

Question 1

Dendrites

Answer 1

Increase the receptive surface

contain receptors for NTs and voltage gated ion channels

Question 2

Cell soma

Answer 2

house keeping Fxn

Receptors that bind chemical transmitters released by afferent neurons

Question 3

Axon

Answer 3

Axoplasm

Myelin sheath

Question 4

Presynaptic terminals

Answer 4

Convert electrical signals into chemical signals

postsynaptic potentials differ from AP

Question 5

Axoplasm

Answer 5

Microtubules and neurofilaments

fast transport anterograde and retrograde

Question 6

Kinesin

Answer 6

Anterograde

Mito and vesicles

Question 7

Dynein

Answer 7

Retrograde
Toxins
Viruses
Growth factors

Question 8

Electrical synapses

Answer 8

Fast
Bidirectional
Gap jxns- hemi-channels-connexons
Pores larger- unselective
CNS- breathing
PNS- visceral smooth muscle and cardiac muscle

Question 9

Chemical synapses criteria

Answer 9

present in the presynaptic terminal
Released in a voltage and Ca dependent manner
specific receptors present in the postsynaptic target cell
means to inactivate the transmitter

Question 10

Chemical synapses provide

Answer 10

Directionality
amplification
potential for excitation and inhibition
Plasticity/remodeling (strengthen/weaken synapse)
Spatial and temporal summation

Question 11

Exocytosis

Answer 11

Release of NT from Presynaptic terminal

Vsnares and Tsnares

Question 12

Synaptobrevin

Answer 12

Exocytosis
binds syntaxin on membrane
on vesicle

Question 13

Synaptotagmin

Answer 13

exocytosis
sensor for Ca
on vesicle

Question 14

SNAP-25

Answer 14

exocytosis

recognition on membrane

Question 15

Syntaxin

Answer 15

exocytosis
binds synaptobrevin
on membrane

Question 16

Endocytosis

Answer 16

Prevents out-of-control enlargement of the presynaptic membrane

Question 17

Botulinum toxin

Answer 17

Muscle weakness due to cleavage of SNAP-25 or synaptobrevin

Question 18

If the reversal potential is more positive than threshold

Answer 18

excitation results

Question 19

if the reversal potential is more negative than threshold

Answer 19

inhibition results

Question 20

Temporal summation

Answer 20

EPSPs at ONE synapse can be produced close together
shorter time constant- no overlap
longer time constant- overlap

Question 21

Spatial summation

Answer 21

Propagation from TWO neurons to axon hillock
Space constant short-delay occurs
Space constant long- propagation along membrane summate EPSP2 causing AP