Neurobiology Week 3 - Synaptic Transmission Flashcards
What is the most prominent synpase found in the vertebrates?
Chemical synpases
How many types of CNS synpases are there?
5
What are the 5 main different CNS synapses?
- Axodendritic
- Axosomatic
- Axoaxonic
- Axospinous
- Dendrodendritic
What’s axodentric synapses?
Axon to dendrite
What’s axosomatic?
Axon to cell body
What’s axoaxonic?
axon to axon
What’s axospinous?
Axon to dendritic spine
What’s dendrodentritic?
dendrite to dendrite
What is grey’s type I synaptic membrane associated with?
Excitatory signalling
What is Gray’s type II synaptic membranes associated with?
Inhibitory signalling
What is Gray’s type II synaptic membranes associated with?
Inhibitory signalling
What are the 3 major neurotransmitter categories?
Amino Acids
Amines
Peptides
What are 3 amino acid neurotransmitters?
- Gamma-aminobutyric acid (GABA)
- Glutamate (Glu)
- Glycine (Gly)
What are the 6 amine neurotransmitters?
- Acetylcholine (ACh)
- Dopamine (DA)
- Epinephrine
- Histamine
- Norepinephrine
- Serotonin (5-HT)
Where are small neurotransmitters synthesised?
In the synaptic terminal
Where are neuropeptides transported from?
The soma
What mechanism are neurotransmitters released?
Exocytosis
Breakdown the mechanisms of neurotransmitter release:
- Exocytosis stimulated by intracellular Ca2+
- Proteins alter conformation - activated
- Vesicle membrane incorporated into presynaptic membrane
- Neurotransmitter released into cleft
- Vesicle membrane recovered by endocytosis
What are SNARE proteins?
What is the synaptotagmin ?
Explain reversal potentials
What is EPSP?
Transient postsynaptic membrane depolarisation caused by presynaptic release of neutotransmitter
What is IPSP
Transient hyperpolarization of postsynaptic membrane potential caused y presynaptic release of neurotransmitters
Describe the generation of an IPSP at an inhibitory synapse
Discuss how a G-protein coupled receptor works
How many connexin sub-units form 1 x connexon
6
What do gap junction channels do?
Allow ionic currents between 2 cells
What’s the term where cells are connected by gap junctions?
Electrically coupled
What’s the average length of a synaptic cleft?
20–50 nm wide
What is an axodendritic synapse?
Post-synaptic membrane on a dendrite
What is an Axosomatic chemical synapse?
Post-synaptic membrane is on a cell body
What is an axoaxonic chemical synapse?
A post-synpatic membrane on another axon
What is an axospinous chemical synapse?
Where a PRE-synatpic axon axon termal contacts a POST-synaptic dendritic spine
What is a dendrodentritic chemical synapse?
Dendrites forming synapses with another dendrite
What is 3DEM?
3 dimensional electron microscopy
What is a grey’s type I synapse?
Usually excitatory
Asymmetrical
What is a grey’s type II synapse?
Usually inhibitory
Symmetrical
What is a grey’s type II synapse?
Usually inhibitory
Symmetrical
What are 3 amino acid neurotransmitters?
GABA
Glutamate (Glu)
Glycine (Gly)
What are 6 amine amino acids?
Acetylcholine
Dopamine
Epinephrine
Norepinephrine
Histamine
Serotonin
What are the 9 peptide neurotransmitters?
Cholecystokinin (CCK)
Dynorphin
Enkephalins (Enk)
N-acytelaspartylglutamate (NAAG)
Neuropeptide Y
Somatostatin
Substance P
Thyrotropin releasing hormone
Vasoactive intestinal polypeptide (VIP)
What are the fastest CNS synpases mediated by?
Amino acid neurotransmitters
Glycine
Glutamate
GABA
What is the key amine mediating neuromuscular synpatic transmission?
Acetylcholine (ACh)
Where are peptide neurotransmitters formed?
The rough ER
What triggers neurotransmitter release?
Depolarisation of the terminal membrane causing calcium channels in to open.
What are SNARE proteins?
SNAREs allow one membrane to snare an- other.
What are SNARE proteins?
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
What is an excitatory postsynaptic potential (EPSP)
postsynaptic membrane depolarization caused by the presynaptic release of neurotransmitter
What is an inhibitory postsynaptic potential (IPSP)
hyperpolarization of the postsynaptic mem- brane potential caused by the presynaptic release of neurotransmitter
