Choline ribosylase was a drug that controls the production of certain irregular neurotransmitters in humans. The drug is used to manage a condition suffered by telepaths where a virus like organism (likely engineered by Psi Corps) that over time subverts and replaces the brain's glial cells with mutant cells that mimic the normal cells function. With mundanes the process is essentially harmless as the mutant cells perform the same task as those they replace, however in telepaths, they stimulate the production of certain neurotransmitters that don't naturally occur within the human body. Initially these neurotransmitters act like stims, increasing the processing of telepathic information and impulses, providing an enhanced boost to a teep's abilities. This is increased cognition and heighte