Which makes it even more important that your competent? hospital strive for tPA delivery in 3 minutes!
In this research in mice the needed time frame for tPA delivery is 3 minutes for full recovery. What is your plan to accomplish that? Or are you ignoring that need?
Electrical 'storms' and 'flash floods' drown the brain after a stroke)
The latest here:
Aging Brain More Vulnerable to Even Mild Oxygen Deprivation
Summary: New research shows that even mild, prolonged exposure to low oxygen levels can significantly disrupt the blood-brain barrier (BBB) in aging brains. Using mice aged 2 to 23 months, scientists found that older mice experienced 4–6 times more BBB breakdown than younger mice under similar hypoxic conditions.
The study also revealed increased brain inflammation in older mice, regardless of oxygen level. These findings may explain why elderly individuals with chronic respiratory or cardiovascular issues are at greater risk for neurodegeneration and cognitive decline.
Key Facts:
- Heightened Vulnerability: Aged mice showed significantly more BBB disruption at higher oxygen levels than younger mice, indicating increased sensitivity.
- Inflammation Spike: Microglial activation, a marker of brain inflammation, was elevated in older mice even under normal oxygen conditions.
- Repair Deficit: Despite steady blood vessel growth across ages, older brains exhibited impaired BBB repair, suggesting weakened vascular resilience with age.
Source: Impact Journals
In a new study, researchers Arjun Sapkota, Sebok K. Halder, and Richard Milner from San Diego Biomedical Research Institute investigated how aging affects the brain’s vulnerability to low oxygen, or hypoxia.
Using C57BL/6J mice ranging from 2 to 23 months of age, they identified specific oxygen levels that disrupt the blood-brain barrier (BBB)—a critical structure that protects brain tissue from harmful substances.
The findings are important for understanding age-related cognitive
decline and the potential risks faced by individuals with chronic
oxygen-limiting conditions such as asthma, sleep apnea, emphysema, and
heart disease.
The BBB is essential for maintaining brain health.
In this study, mild and prolonged hypoxia—called chronic mild
hypoxia—was found to compromise the BBB in mice. Older mice showed
significantly more BBB disruption than younger ones.
Notably,
barrier weakening and blood vessel changes occurred at oxygen levels of
just 15% in aged mice, compared to 13% in young mice. These data suggest
that the aging brain is more sensitive to oxygen deprivation, even at
levels that may be considered only mildly hypoxic.
The
researchers also determined when this vulnerability emerged. The BBB
showed increased sensitivity to low oxygen not only in aged mice but
also in mice as young as 2 to 6 months, with a second spike occurring
between 12 and 15 months—equivalent to middle age in mice.
These findings may reflect age-dependent changes in brain vascular function and remodeling capacity.
“Hypoxia-induced endothelial proliferation was relatively constant across the age range, but advanced age strongly enhanced the degree of BBB disruption (4-6-fold greater in 23 months vs. 2 months old).”
Another key focus was microglial activation, a sign of brain inflammation. Aged mice exhibited higher microglial activation across all oxygen levels, including normal conditions. Chronic microglial activation is closely linked to neuroinflammation and has been implicated in diseases such as Alzheimer’s.
While the rate of
blood vessel formation was constant across ages, the degree of BBB
disruption increased sharply with age, suggesting that repair mechanisms
may weaken over time.
These results may help explain why older
adults with chronic hypoxia-related diseases are at higher risk for
neurodegeneration and cognitive decline. The study also draws attention
to the risks of high-altitude exposure for aging populations, where
oxygen levels naturally drop.
Altogether, these findings
underscore the importance of protecting brain health in older
individuals by managing oxygen exposure and reducing hypoxia-related
risks. The researchers emphasize the need to develop new therapies that
support blood-brain barrier integrity, particularly in aging populations
exposed to chronic or intermittent low-oxygen conditions.
About this neuroscience and hypoxia research news
Author: Ryan Braithwaite
Source: Impact Journals
Contact: Ryan Braithwaite – Impact Journals
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Defining the hypoxic thresholds that trigger blood-brain barrier disruption: the effect of age” by Arjun Sapkota et al. Aging
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