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Synaptic Transmission. Biology 12. Joke of the day…. Review: Synapse. There is a microscopic gap between the terminal end of the axon and the membrane of another neuron. What is synaptic transmission?.
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Synaptic Transmission Biology 12
Review: Synapse There is a microscopic gap between the terminal end of the axon and the membrane of another neuron
What is synaptic transmission? process by which signalling molecules called neurotransmitters are released by one neuron and bind to and activate the receptors of another neuron
Vesicles Small vesicles containing neurotransmittersare located at the very end of the axon end of neurons
Neurotransmitters • Is a chemical messenger that carries, boosts and modulates signals between neurons (and other cells in the body) • Stored in vesicles within synaptic knobs • Examples: acetylcholine, dopamine, serotonin, norepinephrine
How synaptic transmission works: When the impulse, which is moving along the axon, reaches the end of the axon it stimulates the release of neurotransmitters into the synapse. Synaptic vesicles fuse with the axon membrane and release the neurotransmitters into the synapse (exocytosis.)
How it works: The neurotransmitters diffuse across the synapse and combine with receptors embedded in the dendrites of neighbouring neurons to continue the transmission of the impulse (Na+ channels open).
Enhancing or Relaxing: Neurotransmitters can be excitatory (enhancing) or inhibitory (relaxing) in the way that they act.
Drugs • Most drugs act by imitating, stimulating, or blocking the effects of certain neurotransmitters • Check out this cool website! • http://learn.genetics.utah.edu/content/addiction/drugs/mouse.html
Diagram Sheet: • Fill in “Impulse Transmitter” sheet