T cells have many jobs, chiefly destroying pathogens. But as people age, a group of T cells called CD8+ cells begin to infiltrate the brain tissue, where they secrete an enzyme that causes inflammation and prevents brain cells from regenerating. Many more CD8+ cells remain in the bloodstream, but their role in ageing wasn't known until now.
Focal white matter lesions accumulate with age in the central nervous system and, in neurodegenerative conditions, their number correlates with cognitive and physical impairment. Multiple sclerosis is a demyelinating disorder characterized by white matter demyelinating lesions, while grey matter microgliosis and synaptic loss lead to irreversible neurodegeneration, thought to be the dominant mechanism underlying disability progression.
This could open up some interesting possibilities for therapeutic interventions for depression-like behaviors or maladaptive changes in motivational behaviors down the road where microglia are known to play a really important role.
Young, two-month-old lab mice housed with older, 18-month-old mice showed really impaired cognition. Researchers exposed young mice raised in a sterile, microbe-free environment to gut bacteria from old mice, causing the younger animals to perform worse on cognitive tests, as if they had prematurely aged, just like the cohoused mice.
When a person suffers a stroke, physicians must restore blood flow to the brain as quickly as possible to save their life. But, ironically, that life-saving rush of blood can also trigger a second wave of damage - killing brain cells, fueling inflammation and increasing the odds of long-term disability. Now, in a study published in the journal Neurotherapeutics, Northwestern University scientists have developed an injectable regenerative nanomaterial that helps protect the brain during this vulnerable window.
A recent study published in Biological Psychiatry identified a distinct subtype of psychiatric illness marked by brain inflammation, one that cuts across traditional diagnoses and may explain why standard treatments fail for some people (Tang et al., 2025).This new brain imaging study offers an interesting clue. It turns out that across different psychiatric disorders, some people show clear signs of brain inflammation, visible on scans and confirmed through immune system tests.
At a certain point, older folks occasionally develop a penchant for making verbal slurs, mental stumbles, rambling speeches, and confusing responses. They often claim that they have no memory of making those misstatements; they might not be lying. They may be experiencing the most common consequences of advanced age coupled with chronic obesity due to a poor diet. Mind-wandering, confusion, and a reduced ability to organize and focus thoughts are classic early symptoms of dementia.
