WEBVTT

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How does the signal jump across the synaptic gap?

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The process of synaptic transmission involves the release of neurotransmitter molecules

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that float across the synaptic gap and stimulate receptors in the next neuron.

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Let’s enlarge a synapse to take a closer look at this process.

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The axon terminal contains tiny sacs called synaptic vesicles.

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These sacs are filled with special chemicals known as neurotransmitters.

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When the neural impulse reaches the axon terminal,

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the vesicles open up and release their neurotransmitter molecules into the synaptic gap.

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The neurotransmitter molecules float across the gap,

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and find their way to special receptors on the surface of the other neuron's membrane.

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Here's a close up view of neurotransmitter molecules being released into the synaptic gap.

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Each neurotransmitter molecule is like a piece of a  jigsaw puzzle.

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Each receptor or binding site will accept only a certain type of neurotransmitter.

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If the puzzle piece fits and the neurotransmitter binds to the receptor,

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a gate opens to allow ions to flow through a channel in the membrane into the interior of the post synaptic neuron.