Scientists at the National Institutes of Health (NIH) and the Ernest Gallo Clinic and Research Center at the University of California, San Francisco (UCSF) have found a way to influence addiction using lasers – both stimulating the cessation of a habit and conversely creating one depending upon the application. The discovery could lead to new methods of drug addiction therapy.
The addiction experiment, published on the online journal Nature, referenced the work of Dr. Antonello Bonci and lead author Billy Chen of NIDA. Bonci is the scientific director of the intramural research program at the NIH’s National Institute of Drug Abuse (NIDA), where the study was performed. Bonci is also an assistant professor of neurology at UCSF and an assistant professor at Johns Hopkins University.
Chen and his colleagues had been working on animals models which mimicked and studied cocaine addiction. They found the prefrontal cortex played a role in compulsive cocaine addiction.
The primary focus of the research, the prefrontal cortex (PFC), is responsible for the executive functions of complex cognitive behavior, personality, decision making (impulsivity and rationalization), and moderating social behavior – allowing people to differentiate between conflicting thoughts such as good and bad, same and different, and predicting outcomes from actions. Cocaine is addictive primarily because it effects the mesolimbic reward pathway of the prefrontal cortex.
To test whether altering the activity in this brain region could impact addiction, researchers applied a technique called optogenetics, a neuromodulation procedure often employed in behavioral neuroscience. This method, which uses optics and genetics, manipulated the activity of individual neurons using a laser.
Researchers used genetic engineering to insert light-sensitive proteins called rhodopsins into nerve cells (neurons) in the rats’ prefrontal cortex. Activating this brain region with a laser turned the neurons on and off.
Examiners found when they strategically stimulated the prelimbic region of the prefrontal cortex of the brain with a laser in cocaine-addicted rats, the compulsory urge was eliminated. In turn, the procedure could, in theory, establish a habit in those without a preexisting addiction.
The success of terminating the impulse to use cocaine was exciting and promising, as habitual drug use in a major health problem – taking a physical and emotional toll on the user and loved ones. The habitual use of cocaine results in emergency room visits for conditions such as heart attacks and strokes, as well as incarcerations for related crimes. On average, 1.4 million Americans are addicted to the illicit stimulant.
If applied for human therapeutic use, the process would not use lasers but instead rely on electromagnetic stimulation outside the scalp, a technique called transcranial magnetic stimulation (TMS). Clinical trials are now being designed to test whether this approach will work.
A laser – which is an acronym for light amplification by stimulated emission of radiation – is a device that emits light through a process of optical amplification of electromagnetic radiation. Lasers differ from other sources of light because they emit light coherently (in phase), collinearly, and therefore can be tightly honed, allowing for applications like laser cutting.
Lasers are used in everyday life in DVD players and barcode scanners. Militarily they are used to mark targets, calculate range, and speed. This includes LADAR (Laser Detection and Ranging) and LIDAR (Laser Imaging Detection and Ranging) devices, along with old school radar guns, law enforcement use to determine if you are speeding.
Medically laser technology is used to remove body hair, improve vision, whiten teeth, and aid in healing scars and discoloration from epidermal conditions such as acne (post-inflammatory hyperpigmentation).
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