AINEWS
A technique called chemogenetics engineers neurons to respond to a decades old schizophrenia drug. The technique's inventor told a US conference he had no idea at least seven Chinese trials were already running.
Bryan Roth helped invent the technique twenty years ago at the National Institute on Drug Abuse. On Aug. 13, the University of North Carolina pharmacologist stood up at the NIH BRAIN Initiative meeting in Bethesda (the US program to map and modulate brain circuits) and told a roomful of American neuroscientists that at least seven clinical trials of his own creation were already running in China, beyond his line of sight.
The technique is called chemogenetics. It rewires specific neurons so they respond to an otherwise inert drug, and the trials in China use receptors sensitive to clozapine, a decades-old schizophrenia medication. Trade-press reporting describes the room's reaction as "stunned silence." Roth, who co-invented the receptor family known as DREADDs (Designer Receptors Exclusively Activated by Designer Drugs), said he had not been aware of the trials despite being the technology's originator.
What makes the count matter is the category shift. Until recently, the human brain could be modulated from outside by small molecules (SSRIs, anticonvulsants, anesthetics), by electromagnetic fields (deep brain stimulation, transcranial magnetic stimulation, electroconvulsive therapy), or by talk. In the last decade, neurologists have added a second tier: peptides such as GLP-1 receptor agonists, antibodies such as the anti-CGRP (calcitonin gene-related peptide) migraine drugs, focused ultrasound, optogenetics, chemogenetics, gene editing, and cell therapy. Chemogenetics shares an unusual property with gene editing and cell therapy: it alters the neuron itself, rather than the chemistry around it.
Reversibility is what separates chemogenetics from its peers. Optogenetics requires fiber-optic implants and light. Gene editing and cell therapy change the genome and the cell's identity. A DREADD is a synthetic receptor inserted into a chosen population of neurons, and the patient takes clozapine to switch those neurons on or off. The drug wears off; the receptor stays. That makes the therapy titratable in a way that surgery and editing are not, and it lets clinicians re-dose without repeating an operation.
The drug is clozapine, a generic schizophrenia medication. The DREADD system was designed around it from the start, which is why a Phase I trial can repurpose an existing compound instead of waiting for a new one to clear toxicology.
The disclosed indications are epilepsy, Parkinson's disease, and pain. Each is a crowded therapeutic lane with established pharmaceutical options, but none of those options engineers the neuron. A DREADD-based epilepsy therapy would silence the seizure focus on demand, then release it. A Parkinson's application would let clinicians titrate receptor activity in the subthalamic nucleus without the hardware revision cycle of deep brain stimulation.
Community discussion of the disclosure has focused on the gap between US invention and Chinese first-in-human work. Roth's own account makes the gap concrete. A tool he helped invent at a US government lab and refined at a US university is being read out in humans for the first time, and he learned about it from a conference session rather than a co-author email.