Neurobiology Week 3 - Synaptic Transmission

Question 1

What is the most prominent synpase found in the vertebrates?

Answer 1

Chemical synpases

Question 2

How many types of CNS synpases are there?

Answer 2

5

Question 3

What are the 5 main different CNS synapses?

Answer 3

• Axodendritic
• Axosomatic
• Axoaxonic
• Axospinous
• Dendrodendritic

Question 4

What’s axodentric synapses?

Answer 4

Axon to dendrite

Question 5

What’s axosomatic?

Answer 5

Axon to cell body

Question 6

What’s axoaxonic?

Answer 6

axon to axon

Question 7

What’s axospinous?

Answer 7

Axon to dendritic spine

Question 8

What’s dendrodentritic?

Answer 8

dendrite to dendrite

Question 9

What is grey’s type I synaptic membrane associated with?

Answer 9

Excitatory signalling

Question 10

What is Gray’s type II synaptic membranes associated with?

Answer 10

Inhibitory signalling

Question 10

What is Gray’s type II synaptic membranes associated with?

Answer 10

Inhibitory signalling

Question 11

What are the 3 major neurotransmitter categories?

Answer 11

Amino Acids
Amines
Peptides

Question 12

What are 3 amino acid neurotransmitters?

Answer 12

• Gamma-aminobutyric acid (GABA)
• Glutamate (Glu)
• Glycine (Gly)

Question 13

What are the 6 amine neurotransmitters?

Answer 13

• Acetylcholine (ACh)
• Dopamine (DA)
• Epinephrine
• Histamine
• Norepinephrine
• Serotonin (5-HT)

Question 14

Where are small neurotransmitters synthesised?

Answer 14

In the synaptic terminal

Question 15

Where are neuropeptides transported from?

Answer 15

The soma

Question 16

What mechanism are neurotransmitters released?

Answer 16

Exocytosis

Question 17

Breakdown the mechanisms of neurotransmitter release:

Answer 17

1. Exocytosis stimulated by intracellular Ca2+
2. Proteins alter conformation - activated
3. Vesicle membrane incorporated into presynaptic membrane
4. Neurotransmitter released into cleft
5. Vesicle membrane recovered by endocytosis

Question 18

What are SNARE proteins?

Question 19

What is the synaptotagmin ?

Question 20

Explain reversal potentials

Question 21

What is EPSP?

Answer 21

Transient postsynaptic membrane depolarisation caused by presynaptic release of neutotransmitter

Question 22

What is IPSP

Answer 22

Transient hyperpolarization of postsynaptic membrane potential caused y presynaptic release of neurotransmitters

Question 23

Describe the generation of an IPSP at an inhibitory synapse

Question 24

Discuss how a G-protein coupled receptor works

Question 25

How many connexin sub-units form 1 x connexon

Answer 25

6

Question 26

What do gap junction channels do?

Answer 26

Allow ionic currents between 2 cells

Question 27

What's the term where cells are connected by gap junctions?

Answer 27

Electrically coupled

Question 28

What's the average length of a synaptic cleft?

Answer 28

20–50 nm wide

Question 29

What is an axodendritic synapse?

Answer 29

Post-synaptic membrane on a dendrite

Question 30

What is an Axosomatic chemical synapse?

Answer 30

Post-synaptic membrane is on a cell body

Question 31

What is an axoaxonic chemical synapse?

Answer 31

A post-synpatic membrane on another axon

Question 32

What is an axospinous chemical synapse?

Answer 32

Where a PRE-synatpic axon axon termal contacts a POST-synaptic dendritic spine

Question 33

What is a dendrodentritic chemical synapse?

Answer 33

Dendrites forming synapses with another dendrite

Question 34

What is 3DEM?

Answer 34

3 dimensional electron microscopy

Question 35

What is a grey's type I synapse?

Answer 35

Usually excitatory Asymmetrical

Question 36

What is a grey's type II synapse?

Answer 36

Usually inhibitory Symmetrical

Question 36

What is a grey's type II synapse?

Answer 36

Usually inhibitory Symmetrical

Question 37

What are 3 amino acid neurotransmitters?

Answer 37

GABA Glutamate (Glu) Glycine (Gly)

Question 38

What are 6 amine amino acids?

Answer 38

Acetylcholine Dopamine Epinephrine Norepinephrine Histamine Serotonin

Question 39

What are the 9 peptide neurotransmitters?

Answer 39

Cholecystokinin (CCK) Dynorphin Enkephalins (Enk) N-acytelaspartylglutamate (NAAG) Neuropeptide Y Somatostatin Substance P Thyrotropin releasing hormone Vasoactive intestinal polypeptide (VIP)

Question 40

What are the fastest CNS synpases mediated by?

Answer 40

Amino acid neurotransmitters Glycine Glutamate GABA

Question 41

What is the key amine mediating neuromuscular synpatic transmission?

Answer 41

Acetylcholine (ACh)

Question 42

Where are peptide neurotransmitters formed?

Answer 42

The rough ER

Question 43

What triggers neurotransmitter release?

Answer 43

Depolarisation of the terminal membrane causing calcium channels in to open.

Question 44

What are SNARE proteins?

Answer 44

SNAREs allow one membrane to snare an- other.

Question 44

What are SNARE proteins?

Answer 44

SNAREs allow one membrane to snare an- other. SNARES allow a vesicle to “dock” very close to a presynaptic membrane ready for Ca2+ influx & neurotransmitter exocytosis

Question 45

What is an excitatory postsynaptic potential (EPSP)

Answer 45

postsynaptic membrane depolarization caused by the presynaptic release of neurotransmitter

Question 46

What is an inhibitory postsynaptic potential (IPSP)

Answer 46

hyperpolarization of the postsynaptic mem- brane potential caused by the presynaptic release of neurotransmitter