Graded potential/Synaptic communication

Question 1

A membrane potential which initiates as a small local event which in turn might trigger an action potential is called what?

Answer 1

Graded potential (local/generator/receptor potential)

Question 2

What are the two general things Graded potentials are involved with?

Answer 2

1-Originating sensory information

2-Receiving neurotransmitter signals from a synapse

Question 3

Which type of potential (Action potential or Graded potential) is propagated?

Answer 3

Action potential

Question 4

Which type of potential (Action potential or Graded potential) is bigger in terms of amplitude?

Answer 4

Action potential (100 mV)

*GP is 3-20 mV

Question 5

Which type of potential (Action potential or Graded potential) has a longer duration?

Answer 5

Graded potential (ms-sec)

*AP is 1-2 ms

Question 6

Which type of potential (Action potential or Graded potential) is localized?

Answer 6

Graded potential

*AP is cell wide

Question 7

Which type of potential (Action potential or Graded potential) has an all or nothing threshold?

Answer 7

Action potential

Question 8

Which type of potential (Action potential or Graded potential) has a refractory period?

Answer 8

Action potential

Question 9

Which type of potential (Action potential or Graded potential) is decremental (degraded over distance)?

Answer 9

Graded potential

Question 10

Which type of potential (Action potential or Graded potential) is spread by passive electrochemical mechanism?

Answer 10

Graded potential

*AP is voltage gated ion channels

Question 11

What are the two types of summation of graded potentials?

Answer 11

1-spatial summation

2-Temporal summation

Question 12

Collective activity of multiple graded potentials generated by different presynaptic neurons is called what?

Answer 12

Spatial summation

Question 13

Repeated activity of graded potentials from the same presynaptic neuron is called what?

Answer 13

Temporal summation

Question 14

Where is the electrical signal converted into a chemical signal?

Answer 14

bouton portion of the neuron

*dendrite of post-synaptic neuron converts chemical back to electrical signal

Question 15

The zone that stores the elements necessary for a synapse is called?

Answer 15

the active zone

Question 16

The area that is the receiving center and has receptors is called what?

Answer 16

post synaptic density

Question 17

what presynaptic protein element binds a receptor on the post-synaptic neuron to provide mechanical stability for the synapse?

Answer 17

Neurexin

Question 18

Opening of calcium channels in the bouton cause vesicles to fuse/expulse their contents via what proteins?

Answer 18

SNARE proteins (kiss and run hypothesis or complete fusion)

Question 19

Orthograde transport means what?

Answer 19

full vesicle going toward synaptic bouton

Question 20

Retrograde transport means what?

Answer 20

empty vesicle being recycled back to the cell body

Question 21

What two speeds of axonal transport are there?

Answer 21

• Fast transport (400 mm/day)

- Slow transport (1-10 mm/day, lots of stop and go)

Question 22

What are the main two types of neurotransmitters?

Answer 22

• Excitatory post synaptic potentials (EPSPs)

- Inhibitory post synaptic potentials (IPSPs)

Question 23

A neuron can pass information in which two main ways?

Answer 23

• excitation (message sent)

- lack of signal (why didn’t they call)