03b: The Synapse (Pre/Post) Flashcards Preview

Neuroscience > 03b: The Synapse (Pre/Post) > Flashcards

Flashcards in 03b: The Synapse (Pre/Post) Deck (25):
1

Electrical synapse formed by (X).

X = gap junctions (connexins)

2

(Chemical/electrical) synapses are directional.

Chemical

3

You'd find synaptic delay in (chem/electrical) synapse.

Chemical

4

(Chem/electrical) synapses are more amenable to modulation by controlling factors. Why?

Chemical; multiple biochem steps involved

5

In order to cause muscle response to nerve stimulation, Ca has to be applied where and when?

In immediate vicinity of synaptic region, just before the arrival of AP

6

T/F: NT release from pre-synaptic terminal can occur without AP if Ca is present intracellularly.

True

7

Ca is ideal for role of internal messenger because its (intra/extra)cellular concentration is at such (high/low) values at rest.

Intracellular;
Low

8

T/F: Each MEPP represents response of muscle to single ACh molecule.

False - reponse to quantum of NT

9

EPP are usually (X) times (smaller/larger) than MEPP.

X = 2-3 (or n) times larger

10

(X) proteins are implicated in control of exocytosis.

X = SNARE

11

Synapsin function

Tethers vesicles to cytoskeletal structures

12

Synaptotagmin function

Sensese elevation of Ca and triggers formation of fusion pore

13

Botulinum toxin function

Inhibits transmitter release via proteolysis of SNARE proteins

14

List three mechanisms of NT removal from synaptic cleft.

1. Degradation by enzymes
2. Diffusion away from cleft
3. Reuptake by transporters (use Na gradient)

15

List the types of post-synaptic receptors.

1. Ionotropic
2. Metabotropic

16

T/F: Ionotropic receptor is itself an ionic channel.

True

17

T/F: The machinery that converts electrical impulse to chemical signal and back is all confined to synaptic region.

True

18

The "reversal potential" at NMJ occurs when (product/sum/difference) of (X) equals (Y). What is the value of this potential?

Sum;
X = currents of K and Na
Y = 0

-15 mV

19

NMJ ratio of permeability for ACh-induced current.

Na/K = 1.25

20

NMJ: At potentials more negative than reversal potential, current is (positive/negative), which means net flow of (X) is directed (inward/outward).

Negative;
X = positively-charged ions
Inward

21

At NMJ, the reversal potential is more (positive/negative) than resting potential. Thus, response is (de/hyper)-polarization and synapse is (excitatory/inhibitory).

Positive; depolarization; excitatory (EPSP)

22

By definition, an IPSP response drives the (X) away from (Y) potential.

X = membrane potential;
Y = threshold

23

T/F: Inhibitory synapse can achieve its effect without evoking visible change in membrane voltage.

True - stabilizes membrane at/near resting potential

24

Explain the (EPSP/IPSP) provoked by GABA.

IPSP;

Increases Cl-selective conductance, "clamping" membrane potential around E(Cl), which is at the resting potential

25

T/F: Each CNS bouton produces a very small post-synaptic response.

True