What's it mean by "this process is very similar in the brain regions it involves"?
We also know that in humans, mercury causes developmental delays inthe acquisition of language,

and in fact **this process is very similar in the brain regions it involves** and even the genes that are involved.

Question

What's it mean by "this process is very similar in the brain regions it involves"?
We also know that in humans, mercury causes developmental delays inthe acquisition of language,

and in fact **this process is very similar in the brain regions it involves** and even the genes that are involved.

Answer

How did you manage to write that so that it didn't wrap correctly? It was impossible to read, until I copied it somewhere else.
You need more context here. 'also know' and 'similar' refer to something said previously.
What it is saying is that (the previously mentioned thing) and (mercury causing development delays) both affect the same brain regions. They are similar because they both affect the same regions.