MyKell

For the next few years I think working on developing "photoactivatable drugs" would be very rewarding. Specially when it comes to cases when delivery of some drug is aimed to a very specific location in the body. What comes to my mind is drugs used to treat mental illnesses, like antipsychotics and antidepressants. The problem right now is that the drugs we use are very "crude", while many psychiatric diseases are likely to be the product of specific neuronal circuit changes. The crudeness results from drugs acting on multiple gene products and on unrelated neuronal circuits. While research is underway to design more selective drugs(for the first problem), I think it is legitimate to develop a method for a more specific mode of delivery. Photoactivatable drugs, that would have no biological effect when infused, will only work when a machine delivers multiple beams of light that will coincide inside the brain to insure a 3D specific delivery of biological action. This will cut down greatly on side effects, and insure maximum efficacy.
Any thoughts of how such a machine would be developed?

braces_for_impact

It was laready invented, it's called a strobe light.

MyKell

Ok, could you neatly explain how a strobe light relates to what I'm talking about. Or give me a website for using a strobe light in psychiatry clinics.. that would do.

doghouse

A similar strategy is used for certain tumors. Two that come to mind are:

Boron neutron capture therapy
This is used for malignant brain tumors. Boron is administered orally; this accumulates in the brain tumor. Then the brain is irradiated with a neurton beam. This causes the boron to split into high-energy particles, which destroy the surrounding tumor.

Photodynamic therapy
This uses photosensitizing drugs to treat skin tumors and tumors in the esophagus. When these drugs are exposed to certain wavelengths of light, they absorb the light and form reactive oxygen compounds that destroy nearby tissue. The drug is administered and is distributed to all cells, but tends to stay longer in certain cancer cells. Then a LASER is used to activate the drug in the tumor. For esophageal tumors, the LASER is utilized through an endoscope, placed into the esophagus.

MyKell

Ok, I think my original point is being missed:
For tumor cells things are very different from neuronal circuits. Tumor cells are functionally and structurally distinct from normal cells, therefore targeted therapy is much easier, and usually still crude comparing to the idea that I posted. I'm not sure if markers, as those of tumors would be used to label specific neuronal circuits for drug targeting.
By photoactivatable drugs, I mean drugs that will difffuse all over the brain and would only be turned on in a very specific three dimensional location by multiple beams. Each beam could not activate the drug on its own, that is what I was thinking in order to insure spatial precision.

doghouse

How would you propose to get the light into the brain?

Slavik91

Maybe a different energy wave would do. One that could penetrate, yet not damage, living tissues.

I don't recall any specific energy wave at the moment, anyone have an idea?

Lobstrosity

Sound could carry energy into the head without doing damage, although I'm not sure whether it would interact with the drugs in any meaningful way.

doghouse

x-rays

I think Mykell wants to focus the energy on specific brain reigions. You would need high freuquency sound waves (ultrasound) to do this. Something around 1-3 MHz could focus on specific regions and still have a low enough frequncey to penetrate the skull, which has a very high acoustic impedance. I agree it would be challenging to activate a drug in the brain with sound.

Pink Floyd maybe?

MyKell

here's an image that might illustrate my goal more specifically... I really appreciate all your input

Drugs activated by sound? Are there any organic chemists out there that might provide some input on this. Could a chemical cage (surrounding a drug and thus inactivating it) be destroyted by sound