Dysfunction in epigenetics, or alterations in gene expression that affect organism function, is responsible for many neurological disorders, including those above. Scientists know HDACs are involved in changing those expressions, but lack specific information.. To study the difference in the molecules' activity in healthy brains versus the afflicted, researchers spent seven years creating a compound, [11C]Martinostat, that would help examine them at work in the brain.

As they explain in their paper released in Science Translational Medicine, the scientists had deployed their compound in rats and primates, but this first group of eight subjects would be its first human test. Martinostat successfully attached to the HDACs, allowing the scientists to track the molecules using PET scans of the subjects' brains. This showed the researchers where the molecules are in the brain -- and the results were surprising, says The Verge.

The HDAC levels were high in the cerebellum, which controls motor functions, and much lower in white matter, the amygdala and the hippocampus. More shocking was the consistency in these assortments between patients, who all had more or less the same amount of the molecule in the same places in the brain, an intriguing connection between the HDACs and gene expressions related to neurological disease.

But it's still a first step: this version of Martinostat only binds with three of the eleven known HDAC types, leaving the activity of the absent eight uncertain. In addition, it's unknown how the molecule itself changes its way of affecting gene expression as humans age, if at all.