With the use of new imaging agent which binds into tau protein and creates visibility in positron emission tomography (PET) scans, Washington University School of Medicine scientists in St. Louis have revealed that the tangle-causing protein tau as the better marker of patients' cognitive decline and the start of symptoms than amyloid alone. That is particularly true when tau spreads to exact brain region significant for memory, researchers reported in the journal, Science Translational Medicine.

According to STM journal, the new study is still small and requires more research to confirm the findings gathered. But it gives importance on developing drugs that might target both amyloid and tau build-up. Researchers hope that this research could one day help healthy but at-risk people cured from the initial symptoms of Alzheimer's.

Tau proteins or τ proteins are substances that alleviate microtubules. They are abundantly present in neurons of the central nervous system. They are less common in other organs but are also manifested at awfully low levels in CNS astrocytes and oligodendrocytes.

Only recently, scientists have developed a way to carry out PET scans to observe tau deposits like the way they see amyloid build-up to test the theory. However, the expensive scans are used only for study, doctors do not know more how to use them for practical patient concern, WUSTL reported.

Many drugs that targeted to increase amyloid build-up failed in the past years. Still, many researchers think that the cure was not implemented earlier before patients confirmed symptoms. A handful of anti-tau drugs are also being studied and developed to establish claims regarding the recent findings, WUSTL report said.