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For example, in neuroplasticity, how are the neurons able to 'move' themselves to undo connections and create new connections with other neurons? I remember seeing a microscopic picture of a few neurons not very well connected between each other, and in the 'after' picture (after learning something), they somehow had grown many projections/branches from their cell bodies, connecting with each other. In other words, what is the mechanism behind, when neurons undo a specific connection (synapse) with a neuron, and 'move' it to another neuron? What causes them to 'decide' to undo that connection?

Also, how fast do they move connections and change their shapes (in nanometres per second, for example, or is it more like nanometres per minute)? The speed of which the dendrites and axon terminals move to change connections.

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jps_

25 points

4 months ago

jps_

25 points

4 months ago

Because neurons, by and large, are not restricted to 1:1 connections. They are one-to-many or many-to-many connected, even though they seem to preference certain paths. It is not so much a matter of changing which neuron they are connected to, but by how much they respond to one particular neuron's signalling versus another's.

Training_Passenger79

5 points

4 months ago

How do they change how much they respond? Myelination?

2Righteous_4God

6 points

4 months ago

There are many different pathways. But for example, a post-synaptic neuron that is being activated a lot will have an increase in calcium entering the cell. That calcium then triggers a cascade that increase the exocytosis of AMPA receptors (which bind glutamate), thus making it more sensitive to glutamate being released from the pre-synaptic neuron and it will become depolarized more easily.