Term
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Definition
Allow the direct transfer of ionic current from one cell to the next.
Occur at specialized sites called gap junctions. |
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Term
| Postsynaptic Potential (PSP) |
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Definition
Electrical porential generated in the postsynaptic neuron in a gap junction.
Very small (1 mV), so often many will occur at once to continue the action portential. |
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Term
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Definition
Synapses that incorporate neurotransmitters in order to cause an action potential.
Most common form of synaptic transmission in the human nervous system. |
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Term
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Definition
Membrane enclosed spheres in the pre-synaptic element that contain neurotransmitters.
50 nm in diameter. |
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Term
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Definition
Contain soluble protein that appears dark under an electron microscope.
Are large synaptic vesicles. |
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Term
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Definition
Sites of neurotransmitter release.
Located on the intracellular ace of the membrane, jutting out into the cytoplasm. |
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Term
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Definition
Protein accumulated in and just under the postsynaptic membrane.
Contains neurotransmitter receptors which convert intercellular chemical signals into into intercellular signal: change in membran potential or chemical change. |
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Term
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Definition
| Chemical synaps between motor neurons from the spinal cord and skeletal muscle. |
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Term
| Amino Acids at Most CNS Synapses for fast transmissions. |
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Definition
Glutomate (Glu)
Gamma-Aminobutyric Acid (GABA)
Glycine (Gly)
Acetycholine (Ach) - fast transmission at all neuromuscular junctions. |
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Term
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Definition
Special proteins embedded in vesicle membrane.
Responsible for concentrating neurotransmitters inside the vesicles. |
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Term
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Definition
Triggered by the arrival of an action potential in the axon terminal.
Depoarication of terminal membrane causes voltage-gated calcium channels in active zone to open. |
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Term
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Definition
The process in which veicles release their contents.
The membrance of the vesicle fuses to the presynaptic membrane at the active zone, allowing the contents to spill out into the synaptic cleft. |
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Term
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Definition
| The process where the vesicle membrane is recovered, allowing the vesicle to be recycled. |
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Term
| Transmitter-gated ion channels |
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Definition
Receptors that are membrane spanning proteins consisting of 4 or 5 sub units.
Pore is usually closed in the absence of neurotransmitters.
When neurotransmitters bind to the extracellular region of the channel, the pore opens allowing ions to flow through. |
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Term
| Excitatory Postsynaptic Potential (EPSP) |
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Definition
A transient postsynaptic membrane depolarization caused by the presynaptic release of neurotransmitters.
Synaptic activation of Ach-gated and Glu-gated ion channels causes EPSP, for example. |
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