University of Pittsburgh researcher, Dr. Susanne Ahmari, is using optogenetics to study obsessive-compulsive disorder. In optogenetics, scientists insert genes for light-sensitive proteins into the brains of animals. They can then control and study neurons which have been genetically sensitized to light.
Dr. Ahmari’s lab is filled with mice as described in the article:
“They have an optical fiber painlessly inserted into their brains, and it can be hooked up to a cable that transmits pulses of laser light. The light goes to specific parts of the brain, stimulating or inhibiting certain neurons, and scientists like Dr. Ahmari can then see how that changes the animals’ behavior.”
These types of studies amaze me, and give me hope that someday down the road, we will know more about what causes OCD, and more importantly, what can cure it.
The article goes on to say:
“Brain imaging studies in people with OCD have shown that a circuit between parts of their frontal cortex and a deeper structure known as the striatum is hyperactive when they are experiencing obsessive thoughts.
But in humans, she [Dr. Ahmari] said, ‘you can’t prove cause and effect.’ In other words, you don’t know if activity in this circuit is driving OCD or is a byproduct of it.
The work her lab has done in mice suggests the circuit helps cause OCD. After inserting light-sensitive genes into the equivalent circuit in mice and pulsing blue laser light into that part of the brain for several days, researchers found that the mice began grooming themselves excessively — the mouse equivalent of obsessive behavior….
…Now that they have evidence this circuit is a trigger for obsessive behavior, her lab is trying to use another kind of laser light to decrease obsessive behaviors in mice, but it’s too early for those experiments to have yielded results, she said.”
I recommend reading the article, which goes into more detail and also discusses the possibility of optogenetics being used someday to treat humans. And optogenetics has not only been used to research OCD; studies on epilepsy, bipolar disorder, and drug addiction are also discussed.
Dr. Ahmari is not only a research scientist, but also a psychiatrist who treats patients with OCD. She says her patients are her motivation for continuing to study OCD using optogenetics:
“I’ve had some wonderful patients who are really interested in what’s happening in their brains because they want to know why they feel compelled to do this thing they don’t want to do.”
Ah, the million dollar question. I’d like an answer to that too!