Researchers at Georgia State University discovered shocking new information on the relationship between neuron activity and deep brain blood flow, as well as how salt consumption affects the brain, in a landmark study. When neurons are stimulated, blood flow to the region is normally increased immediately.
For those who suffer from high blood pressure, the doctor asks to avoid salt or limit the intake of the same. However, in practice, almost every food has a part of it, and people do not prefer to have food without salt in many cases. Scientists have checked a few facts about salt and its effects on the brain’s blood flow, which are really surprising for everyone.
Scientists Have Observed, How Salt Affects Brain Blood Flow
Neurovascular coupling, also known as functional hyperemia, occurs when blood vessels in the brain called arterioles to dilate. The notion of neurovascular coupling underpins functional magnetic resource imaging (fMRI): specialists look for areas of poor blood flow to diagnose brain diseases.
Previous research on neurovascular coupling, on the other hand, has focused on superficial parts of the brain (such as the cerebral cortex), and scientists have largely looked at how blood flow varies in response to sensory stimuli from the environment (such as visual or auditory stimuli). Little is known about whether the same principles apply to interoceptive signals, which are created by the body.
An interdisciplinary team of scientists led by Dr. Javier Stern, professor of neuroscience at Georgia State University and director of the university’s Centre for Neuroinflammation and Cardiometabolic Diseases, developed a novel approach that combines surgical techniques and state-of-the-art neuroimaging to study this relationship in deep brain regions.
The study focused on the hypothalamus, a deep brain region involved in key physiological functions such as drinking, eating, body temperature control, and reproduction. The study, which was published in the journal Cell Reports, looked at how salt intake affected blood flow to the hypothalamus.
“Because the body must carefully regulate sodium levels, we chose salt. There are even cells in our bodies that can detect the level of salt in your blood, “As mentioned by Stern. “When you ingest salty food, your brain recognizes it and initiates a series of compensatory measures to lower sodium levels.”
The body does this in part by activating neurons that promote the synthesis of vasopressin, an antidiuretic hormone that is necessary for a proper salt balance. The researchers discovered a decrease in blood flow when the neurons in the hypothalamus became activated, in contrast to prior studies that demonstrated a positive link between neuron activity and increased blood flow.
“We were shocked by the findings because we saw vasoconstriction in the cortex, which is the polar opposite of what most people experience in response to a sensory event,” Stern said. “In illnesses like Alzheimer’s, as well as after a stroke or ischemia, reduced blood flow in the cortex is frequent.”
The term “inverse neurovascular coupling” was coined by the researchers to describe a decrease in blood flow that leads to hypoxia. They also observed the following distinctions: Vascular responses to brain inputs are highly localized and characterized by fast dilation. The hypothalamic response was extensive and lasted a long time.
The findings raise intriguing questions about the implications of high blood pressure on the brain. Between 50 and 60% of hypertension is assumed to be salt-dependent, meaning it is brought on by excessive salt consumption.
In animal models, the researchers seek to see if this inverse neurovascular coupling mechanism plays a role in the pathogenesis of salt-dependent hypertension. They want to use their technology to treat depression, obesity, and neurodegenerative diseases, among other brain ailments.
