'Signature' of aging existing solely in brain identified

A team of researchers have identified signature of aging in the brain, suggesting the possibility of slowing the cognitive decline in older people in the future.

The researchers from Weizmann Institute found an evidence of a unique "signature" that may be the "missing link" between cognitive decline and aging and showed that the immune system actually plays an important role both in healing the brain after injury and in maintaining the brain's normal functioning and that, this brain-immune interaction occurs across a barrier that is actually a unique interface within the brain's territory.

Researcher Michal Schwartz said that the choroid plexus acts as a 'remote control' for the immune system to affect brain activity and biochemical 'danger' signals released from the brain are sensed through this interface, in turn, blood-borne immune cells assist by communicating with the choroid plexus and this cross-talk is important for preserving cognitive abilities and promoting the generation of new brain cells.

This finding led Schwartz and her group to suggest that cognitive decline over the years may be connected not only to one's "chronological age" but also to one's "immunological age," that is, changes in immune function over time might contribute to changes in brain function, not necessarily in step with the count of one's years.

They discovered that one of the main elements of this signature was interferon beta, a protein that the body normally produces to fight viral infection and appears to have a negative effect on the brain.

When the researchers injected an antibody that blocks interferon beta activity into the cerebrospinal fluid of the older mice, their cognitive abilities were restored, as was their ability to form new brain cells.

The study is published in Science.