UW professor developing new probe to study the living brain

Janusz Pawliszyn, a UW chemistry professor, is working with researchers from Concordia University and the Centre for Addiction and Mental Health to develop a probe that can be used to safely explore live subjects&rsquo; brains.</p>

The 0.1mm wide brain probe is covered in a coating which, when placed in tissue, extracts small molecules — for example neurotransmitters and hormones — that can then be analyzed by laboratory equipment. Technology for this coating is based on a sample preparation technique known as solid phase microextraction (SPME) developed by professor Pawliszyn in the early ‘90s. Pawliszyn likened the coating to paint.

“You have this high tech coating which is like a paint. You paint this wire and when you put it in tissue — because the coating is designed in a way that prevents the absorption of macromolecules such as protein, tissue components, liposomes, lipoproteins — small molecules can penetrate into this extraction phase,” Pawliszyn explained. “When you put it in any tissue, including brain, you extract small molecules from it.”

It was recently announced that the project will be receiving almost $1 million over three years from three Ontario brain research funding agencies — CQDM, Brain Canada, and the Ontario Brain Institute.

According to Pawliszyn, the procedure for obtaining samples in humans with the probe will be similar to existing practices used by surgeons to access the brain, where a hole is made in the skull by the area of interest and then a probe is inserted using a positioning device. A portion of the funding will be put towards developing such a device for the brain probe.

As Pawliszyn explained, “With our probe, we are not modifying the standard procedure which surgeons are using right now to access the brain. We just use the same protocol. Part of the project which we are funded to do by Brain Canada is actually trying to develop good positioning devices to precisely put the probe.”

Once the sample has been obtained by the probe, it can be analyzed using mass spectrometry to identify the molecules present and their quantities.

“We use sophisticated instrumentation called liquid chromatography mass spectrometer,” he said. “Masspectromery is an area which [has developed] very rapidly in the last decade. They are very, very powerful instruments which can tell you with high precision what’s the mass of the compound even if there are millions of them in one sample. This technology is really helping to facilitate the success of SPME.”

The probe could not only lead to more effective analysis of, and less harm to, the brains of animals used in drug testing, but also aid in the development of treatments for neurological disorders such as Alzheimer’s disease and depression in humans. The development of a human-safe probe that could result from this project may lead to better, tailored-made care for the individual.

“The brain is quite a personalized organ,” he pointed out. “This means your brain responds in different ways to different stimuli than somebody else. We can very easily see the people who are easily stressed by some circumstance, [yet] there are other people who don’t care … Procedures need to be very personalized. Understanding more about how different brains operate [could allow] doctors to develop personalized procedures eventually.”