Do not Bodies and Light act mutually upon one another; that is to say, Bodies upon Light in emitting, reflecting, refracting and inflecting it, and Light upon Bodies for heating them, and putting their parts into a vibrating motion wherein heat consists? — Sir Isaac Newton
In keeping with contemporary advances in neuroscience, neurology, and psychiatry, it was inevitable that studies of the brain would eventually converge with a method of streamlining mental illness treatment with optimum precision via neuronal manipulation. For the last decade, Gero Miesenboeck, professor of physiology at the University of Oxford, has been working to alter the genetic coding of electrical activity in nerve cells with highly specialized techniques involving external light sources (previously recognized by Francis Crick). Building on Misenboeck’s research, scientists at M.I.T., Stanford, and the University of California, Berkeley have gained valuable insight into how neurons can be manipulated with high temporal resolution. Otherwise known as optogenetics, the targeting of specific neuronal pathways is currently being developed and promises to revolutionize the way brain activity and behavior can be transformed for people with mental illness. In particular, such brain areas as the amygdala, hippocampus, and nucleus accumbens may respond to optogenetic manipulation that could recalibrate abnormal neuronal circuitry associated with such disorders as schizophrenia, autism, depression, anxiety, and substance dependence.
The basic mechanics of optogenetics involves inserting a gene that makes nerve cells sensitive to light (isolated from algae or other microorganisms) into the brain by using a snippet of DNA and an innocuous lentivirus to proliferate the gene’s presence on the surface of selected neurons. Subsequently, a manually placed fiber-optic cable can deliver light to the affected areas causing light-sensitive proteins (opsins) to respond by turning the genetically sensitized neurons on or off (like a light switch). One way to think about the process is similar to command guidance for improved precision after identifying exact neurotransmitter dysregulation as opposed to the current “scattershot” approach with psychopharmacology. The expression of symptom-related phenotypes can be attenuated by deactivating neuronal circuits, while other circuits involving dormant cellular pathways can be innervated for optimum functioning (the fiber-optic neural interface combined with the speed and precision of light literally reconfigures electrochemical activity).
Current testing for optogenetics has primarily taken place with fruit flies (Drosophila) and lab mice; but according to some scientific prognosticators is expected to be incorporated in neurology and psychiatric treatment for humans within the next five years.
In conclusion, the promise of reduced symptomatology via optogenetic intervention is exhilarating considering the implication for treatment-resistant patients and previously assumed refractory mental states (further experimental research is planned to integrate the entire spectrum of available therapeutic benefits with this intervention). According to Karl Deisseroth, a medical doctor and optogenetics research specialist at the Department of Bioengineering and Psychiatry at Stanford University, “By no means do optogenetic technologies stand alone; instead this approach must be integrated well with existing sophisticated psychiatric disease-model research methods spanning behavior, psychology, imaging, electrophysiology, pharmacology, and genetics. Additional technologies also need to be developed further for this approach to reach its full potential.”1
1. Karl Deisseroth. “Optogenetics and Psychiatry: Applications, Challenges, and Opportunities,” in Biological Psychiatry (2012: 71), 1030–32.
*Learn more at www.optogenetics.org
(This article was first published in the NPI newsletter, Winter 2013).