Scientists may have found a potential cure for anxiety after isolating and enhancing a molecule in the rhesus monkey's brain.
Andrew Fox, a researcher at UC Davis, and co-author Tade Souaiaia of SUNY lead a research team in an experimental study investigating whether anxiety-related and depression-related behaviors can be mitigated by manipulating the amygdala , the part of the brain that controls memory and emotions associated with memory.
To land on a particular molecule – in this case neurotrophin-3 – the team used RNA sequencing, manipulation of viral vector genes, functional brain imaging, and behavioral phenotyping to reconstruct the primate brain. What they found confirmed earlier research indicating that the brain of young monkeys, whose researchers termed an "anxious temperament", had alterations compared to neurotypic monkeys. This is described in the research report:
Forty-six non-human primates were longitudinally examined for behavioral inhibition, cortisol and brain metabolism during a 30-minute exposure to a potentially threatening human intruder who had no eye contact (NEC) with the monkey. The NEC context causes behavioral inhibition, which is an important risk factor for children developing stress-related psychopathology. During the NEC, we measured the inhibition of behavior (freezing and voice reduction).
When they found out which monkeys showed a fearful temper, it was easy to increase the neutrophin-3 molecule in their brains by gene therapy. This was achieved by injecting the monkey amygdala with a modified virus targeting the neutrophin-3 molecule, triggering its activation by being essentially tempted to overexpress itself. The hypothesis was that the glowing of the molecule would bring the changes brought on by the machinations of fear-temperament to some sort of CTRL-Z.
According to the team's research report, it was a success. Researchers wrote that monkeys who received the treatment showed a "significant reduction" in anxiety ̵
We are just beginning. Neurotrophin-3 is the first molecule that we have been able to demonstrate in a non-human primate to be causally related to anxiety. It is one of possibly many molecules that might have this effect. It could be hundreds or even thousands more.
This breakthrough has amazing implications for the study of mental health and psychopathology. Millions of people around the world suffer from anxiety and depression. Targeted gene therapy that can alleviate this behavior could be the first general remedy for these conditions that the world has ever seen. But scientists are still sequencing primate RNA, and it will be important to investigate the long-term effects of amplifying molecules in the amygdala – it could take a long time for us to see any human trials.