Hi psychoactive molecules,
Neurotransmitters are generally pretty benign and non-aggressive; but if you do piss them off, some of them can drain your psychoactive power and some can fire out an action potential!
For your info, action potentials are fired out by excitatory neurotransmitters. When you meet inhibitory neurotransmitters, your power just doesn't work at all. Sometimes watch out for the tiny calcium ion bullets too!
P.S. The appearance/clothes of Dopamine and Serotonin are just temporary and random.