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Beginner question here:

The definition of decussation I see is the crossing through the midline of a bunch of neurons. But I was wondering if there was a little more to it than this, because I'm given the impression in readings that this is a somewhat difficult task to perform developmentally, like the body might have to take extra effort to regulate the crossing so that the neurons do not interfere. So when nerves from both eyes cross, for example, do they pass AROUND each other or do the bundles of nerves all weave through each other?

Thanks in advance.

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up vote 2 down vote accepted

The optic nerve fibers cross inside the optic chiasm sharing the same shell:

enter image description here

The crossing fibers go ones between others, like on this classical picture -

enter image description here

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