Since the start of the 2020 pandemic, mental health has become a central topic of conversation. The isolation brought to light a previously overlooked but increasingly prevalent illness: depression. Recent research has discovered how a small population of nerve cells appears to be responsible for blood flow and neuronal activity throughout the brain, which could be one of the causes of depression. The research was published in the journal Science Advances, from the American Association for the Advancement of Science.
These findings could have significant implications for the study of sleep and dementia
Going into detail, scientists detected how stress can cause alterations in tiny sugar chains within the brain, which could help explain why some people develop depression. This type of cell is known as a type I nNOS neuron, and while present in small quantities, primarily in the deep cortical layers, it is considered vulnerable to mental stress. Moreover, these findings could have significant implications for the study of sleep, dementia, and overall brain health.
The discovery of a small group of neurons that controls blood flow
Scientists have discovered how stress can lead to serious mental health problems. To better understand the function of type I nNOS neurons, researchers at Pennsylvania State University selectively extracted them from the brains of mice to study their effects. This led to the discovery of a small group of neurons that controls blood flow and overall brain activity. The finding highlighted that chronic stress triggers a specific chemical reaction in compounds called O-glycans, which alter the function of key proteins in brain regions responsible for emotions. This is fundamental to understanding how emotions behave in the brain.
The scientists collaborated with specialists in neurobiology and biotechnology
This mechanism had never been previously identified in the development of depression, according to researchers led by C. Justin Lee and Boyoung Lee at the Institute of Basic Science in South Korea. Thus, without type I nNOS neurons, the brains studied showed reduced blood flow, weaker blood pulsation (vasomotor activity), and reduced neuronal activity. The scientists collaborated with specialists in neurobiology and biotechnology. It was basic experimental research in animal models, as explained above. This is how the research took shape and yielded results.
Experts describe depression as a disorder that can develop from a complex interaction of psychological, environmental, and genetic factors
Among the symptoms of depression are extreme fatigue, difficulty sleeping, and severe problems relating to others or maintaining normal routines. “In the brain, arteries, veins, and capillaries help move fluid through constant dilation and constriction every few seconds, which we call spontaneous oscillation,” explains biomedical engineer Patrick Drew. Experts describe depression as a disorder that can develop from a complex interaction of psychological, environmental, and genetic factors. “Previous work in our lab has shown that nNOS neurons are important for regulating cerebral blood flow. After identifying and eliminating a subset of these neurons, we observed a significant reduction in the amplitude of these oscillations,” the researchers explain.
Brain dysfunction results in weaker communication between neurons and an imbalance in the circuits that regulate emotions. Research suggests that type I nNOS neurons may play a role in several key brain processes. The central aim of the research was to explore whether other biological processes might be involved in the onset and progression of depression. For example, delta waves are closely linked to sleep, and researchers observed that reduced blood flow and neuronal activity were greater during sleep in the animals used in the study. Ultimately, according to Drew, “The loss of these rare neurons due to chronic stress could be an unexplored environmental cause of poor brain health.”