While the exact causes of neurodegenerative brain diseases like Alzheimer’s and dementia are still largely unknown, researchers have been able to identify a key characteristic in affected brains: reduced blood flow. Building upon this foundational understanding, a team at Penn State recently found that a rare neuron that is extremely vulnerable to anxiety-induced stress appears to be responsible for regulating blood flow and coordinating neural activity in mice.

The researchers found that eliminating type-one nNOS neurons—which make up less than 1% of the brain’s 80 billion neurons and die off when exposed to too much stress—resulted in a drop in both blood flow and electrical activity in mice’s brains, demonstrating the impact this neuron type has on the proper brain functions of animals, including humans.

The research appears in eLife.

Alzheimer’s disease (AD), the leading cause of dementia, affects nearly 40 million individuals globally, resulting in a gradual loss of memory and independence. Despite extensive research over the past decades, no treatments have been found that can halt or reverse the progression of this devastating disease.

In AD, a major contributor to neuronal dysfunction is the protein tau. Tau typically plays a crucial role in keeping the internal structure of neurons stable, much like train tracks help trains stay on course. However, in some diseases, tau undergoes abnormal modifications and starts to aggregate, disrupting this transport system, thus leading to neuronal damage and subsequent memory loss.

An international team of researchers has reported a new mechanism by which boosting the natural metabolite NAD⁺ can protect the brain from the degeneration associated with AD. Their paper, titled “NAD⁺ reverses Alzheimer’s neurological deficits via regulating differential alternative RNA splicing of EVA1C,” is published in Science Advances.

Adolescence, the life stage that marks the transition between childhood and adulthood, is known to be a vital period for the brain’s development. During this critical phase, people’s mental abilities, including their problem-solving and memory skills, rapidly improve.

Past neuroscience studies have tried to link these observed cognitive improvements during adolescence to changes in the structure of the brain and the connections between different brain regions. Nonetheless, the relationship between changes in the brain and specific aspects of cognitive performance has not been fully elucidated.

Researchers at Vanderbilt University, CNRS Université de Lyon, and Wake Forest School of Medicine recently carried out a study involving monkeys that was aimed at shedding new light into the underpinnings of mental maturation during adolescence. Their findings, published in Nature Neuroscience, suggest that the cognitive development of adolescent monkeys is associated with a refined connectivity between brain regions, while changes in gray matter structure play a lesser role.