A radiotracer specifically binds to a major class of brain receptors when injected into living rats and humans, lighting them up in PET scans. The compound, called [11C]K-2, was designed and tested by a large team of scientists in Japan, led by Professor Takuya Takahashi of the department of physiology at Yokohama City University Graduate School of Medicine. It shows promise for diagnosing and treating epilepsy and for improving understanding of psychiatric diseases. Details of the team’s findings were published in the journal Nature Medicine.