Synaptic Transmission

Question 1

Gap junctions are _____ synapses.

Answer 1

Electrical

Question 2

Gap junctions are made of _____, which form a _____ when they meet with those of a neighboring cell

Answer 2

connexons; gap junction channel

Question 3

Gap junctions are most common where?

Answer 3

Mammalian CNS

Question 4

Action potentials in a pre-synaptic electrically-coupled neuron causes a small ionic current to flow into the post-synaptic neuron. This causes a ______

Answer 4

postsynaptic potential

Question 5

Neurotransmitter receptors are mostly found on the ______

Answer 5

postsynaptic density

Question 6

Small neurotransmitters such as amino acids and amine are stored in _______, while larger peptides are stored in ______

Answer 6

synaptic vesicles; secretory granules/dense-core vesicles

Question 7

Neurotransmitters are released from an area called the _____

Answer 7

active zone

Question 8

Gray’s type I membranes are _______ and usually ______, while Gray’s type II membranes are _______ and usually _________

Answer 8

asymmetrical; excitatory; symmetrical; inhibitory

Question 9

Why do action potentials in motor neurons always produce action potentials in the muscle cells they innervate?

Answer 9

Neuromuscular junctions have large synapses with many active zones, which all activate at once by an action potential.

Question 10

Glutamate, glycine and GABA are examples of ______ neurotransmitters.

Answer 10

amino acid

Question 11

Serotonin, histamine and catecholamines are examples of ______ neurotransmitters.

Answer 11

amine

Question 12

Substance P and opioids are examples of _______ neurotransmitters.

Answer 12

peptide

Question 13

Peptide neurotransmitters are synthesized in the ________, and are transported to the ______ by anterograde transport.

Answer 13

cell body, axon terminal

Question 14

Amino acid and amine NTs are synthesized in the _______

Answer 14

axon terminal

Question 15

Neurotransmitters are released into the synapse by _______

Answer 15

exocytosis

Question 16

Depolarization cause ______ channels to open, which allow for NT release by _______ to initiate exocytosis.

Answer 16

calcium; modifying snare proteins

Question 17

Secretory granules need _______ stimulation than synaptic vesicles to release.

Answer 17

more

Question 18

________ increase the chance of an AP, while _______ decrease the chance of an AP.

Answer 18

Excitatory postsynaptic potential; inhibitory postsynaptic potential

Question 19

_______ neurotransmitter receptors allow for fast synaptic transmission, while _______ receptors allow for slower and longer lasting transmission.

Answer 19

Transmitter-gated; G-protein-coupled

Question 20

Transmitter-gated receptors are also called ______ or _____. G-protein coupled receptors are also known as ______

Answer 20

Ligand-gated; ionotropic; metabotropic

Question 21

Ligand-gated channels are usually _______.

Answer 21

ion channels

Question 22

Na+ permeable channels are usually ______, while Cl- channels are usually _______

Answer 22

Excitatory; inhibitory

Question 23

Glycine and GABA are _______ neurotransmitters, while acetylcholine and glutamate are _______

Answer 23

Inhibitory; excitatory

Question 24

Autoreceptors are found on the _______

Answer 24

presynaptic axon terminal

Question 25

Neurotransmitters are removed from the synapse in what 3 ways?

Answer 25

1. Enzymatic degradation
2. Presynaptic reuptake
3. Diffusion away from synapse/uptake from glial cells

Question 26

One quanta is how many synaptic vesicle(s)?

Answer 26

One

Question 27

Spacial summation refers to adding EPSPs from ______

Answer 27

multiple synapses on the same dendrite

Question 28

Temporal summations refers to adding EPSPs from _______

Answer 28

the same synapse in rapid succession

Question 29

Length constant of a dendrite refers to ______

Answer 29

the distance an EPSP can travel before it is at 37% of its original strength

Question 30

What are the 3 factors influencing whether or not an EPSP will cause an action potential?

Answer 30

1. Distance from spike-initiating zone
2. The number of coactive EPSPs
3. Length constant of the dendrite