I think this is a beautiful piece of poetry with great impact, that I had to read again right away. I just have a couple of suggestions.
Perhaps you don't need the second hyphen in 'now-loose-neurons'; the first one I agree is needed to tie the words together, but I wouldn't do it to a noun anyway, and I think it would have more impact as an isolated word.
I also wonder whether 'wall' would work better as the final word; 'wallpaper' seems to lose impact by being a bit too long, and since there are so many kinds of wallpaper it's hard to imagine the one in this image. So for me, it works better as: and flung serotonin against the wall.
To be honest, its taken me a really long time to digest this poem properly. I had a hard time retaining the sense within the poem. I felt rather than saw when I read it. Which offered a different effect of impact.
As for technique, I don't know whether you meant to do it, but the subject abruptly changes in-between. The 1st three lines proceed well, until you reach the middle, there is a sudden change there. Since it is your poem, I will not judge so harshly.
In summation, this poem is very different, and very well done.