Rhesus monkeys at the University of California – Davis are showing promise to cure anxiety after scientists isolated and boosted a single brain molecule. Researchers Andrew Fox, of UC Davis, and Tade Souaiaia, of SUNY, lead a study to determine if manipulation of the amygdala could mitigate behaviors that relate to anxiety and depression. The amygdala is the portion of the brain that controls memories and the emotions associated with them.
Using RNA sequencing, behavioral phenotyping, viral-vector gene manipulation, and functional brain imaging to reverse engineer their brains, the researchers were able to isolate a specific molecule, neurotrophin-3. During this process, earlier research was confirmed that the brains of neuro-typical monkeys were different from young monkeys who exhibit anxiety.
The monkeys were observed during experiments to determine which monkeys displayed behaviors associated with anxiety. The assessment included forty-six rhesus monkeys. Brain metabolism, cortisol, and behavioral inhibition were observed while they were exposed to an intruder who they perceived as a potential threat.
After the over-anxious monkeys were identified, they received an injection into the amygdala with a virus that had been modified to target the neurotrophin-3 molecule. This triggered the activation of the molecule to over-express. Monkeys who had received the injection showed a significant reduction in anxiety. The scientists believe that other molecules in the brain could produce a similar result.
Neurotrophin-3 is the first molecule shown to be related to anxiety in the primates. Potentially, the same effect could be observed in many others. Targeted gene therapy affecting anxious and depressed behaviors could potentially cure the behaviors of millions of people suffering these symptoms all over the world. More studies are underway to observe the long-term effects of boosting these molecules before human trials will be possible.