Anatomy of a synapse Flashcards
What did Santiago Ramon y Cajal do?
He made drawings looking at the nervous system. He drew neurons, cell bodies, axons, and astrocytes. He also came up with the idea of synapses
Desribe the structure of a typical neuron
a typical neuron has soma (cell body) this is where the nucleus is located. Nerve fibers that are capable of rapidly conducting impulses away from the cell body
describe the soma
The bulbous end of a neuron, contaning the cell nucleus
Describe an axon
nerve fibers that are capable of rapidly conducting impulses away fro the neuron cell body.
Describe dentrites
A long, branch outgrowth or extension from a neuron that carries electrical signals from synapses to the cell body.
what is the presynaptic terminal?
A specialized area within the axon of the presynaptic cell that contians neurotransmitters enclosed in synaptic vesicles.
How does communication between neurons occur?
Communication between neurons occurs at the synapses. Synapses are specialized junctions. Excitatory messages cause the next cell to “fire” - and continue to carry the action potential.
What are the types of synpases?
Electrical and chemical synapses
Describe electrical synapses
Electrical transmission is mediated between neurons by clusters of intercellular channels called gap junctions. They see very rapid transmission. Electrical synapses are bidirectional as the current can flow between two neurons at these electrical synapses.
Describe Chemical synapses
• More common in the NS.
Synpatic vesicle cycle
• We have synaptic vesicles that have to be docked at active zones; this docking requires a number of proteins
Proteins are important for _______________________________________
Synaptic Vesicle cycles
Describe neurotransmitters
• Chemical messengers that transmit info between neurons
Glia ________around the cell
wraps
What are the different types of glia ?
Astrocytes
Astrocytes
• Found in the CNS
Oligodendrocytes
• Found in the CNS
Microglia
•Found in the CNS
Schwann cells
• Found in the PNS
Describe how astrocytes detect and control synaptic transmission
• Astrocytes are in close contact with neurons
Describe Synapses
specialized structures where nerve cells communicate with each other through a process called synaptic transmission.
Why are synapses important?
• Synapses are functional units of the brain and are targets of many diseases and drugs.
Active zones
are sites where synaptic vesislces exocytosis and fusion occurs
Periactive zone
are sites where synaptic vesicles endocytsis occurs
what are the functions that active zones perform in neurotransitter release ?
- They dock and prime synaptic vesicles
Describe the postsynaptic density
• PSD is a protein-dense specialization attached to the postsynaptic membrane
Descirbe the 4 different active zones
- Dense projections: neuromuscular junction C.elegans
Cytoskeletal matrix assembled at Active zones (CAZ)
The CAZ is a proteinaceous cytomatrix that serves as an organizational platform for proteins involved in synapse assembly and regulation
How can syanpses differ in relase probabilities?
Not all synapses are the same. They can differ in release probabilities, this is true across and within species.
Name 6 reasons why synapses can differ in their release probabilities
- Active zones per synapse. More active zones lead to more neurotransmitter release.
Some proteins found at Active zones are
SNARE proteins
Domains of proteins allow them to __________________________
interact with each other
describe RIM
• RIM binds to a synaptic vesicle called Rab3
What happens without RIM and RIM BP
the Ca2+ channels are no longer in close proximity to these synaptic vesicles and the recruitment of Ca2+ channels reduces the amount of neurotransmitter release.
describe ELKs
• ELKs regulate Ca2+ influx and neurotransmitter release
Describe Liprin
• Liprin plays key roles in AZ formation and synaptic vesicle accumulation
Describe Munc-13
• Munc-13 is an AZ protein that is essential for syanptic vesicle priming.
