That's not really news to me, I read that already in Tihkal?
Its not so much the fact its present, but where and how much that I thought was interesting.
This is important because of the levels produced as well as areas of the brain which is producing it.
The article insinuates that it is produced in amounts similar to other neurotransmitters and could be connected to other neurological/metabolic functions rather than just dreaming/ near death experiences.