The secret to weight loss could be in the brain.
Researchers have uncovered newly identified sensory neurons that ferry messages from fat tissue to the brain, according to Science Daily.
“The discovery of these neurons suggests for the first time that your brain is actively surveying your fat, rather than just passively receiving messages about it,” said Li Ye, Ph.D., the Abide-Vividion Chair in Chemistry and Chemical Biology and associate professor of neuroscience at Scripps Research, who was the co-senior author of a new study.
“The implications of this finding are profound.”
The study, which was published in Nature, has found that messages to fat tissues can be streamlined by the brain, finding it can directly send messages to fat tissue and influence the body’s metabolic processes rather than responding to hormonal signals in the blood.
Led by a team from Scripps Research Institute, co-senior authors Ye and Ardem Patapoutian developed two new methods to look into the relationship between sensory neurons and fat tissue.
First, they used an imaging approach called HYBRiD that turned mouse tissues transparent and allowed them to track the paths of neurons through fat, or adipose tissue.
To see how neurons in adipose tissue worked, researchers used a second new technique, which they named ROOT, for “retrograde vector optimized for organ tracing.” This allowed them to selectively destroy small parts of sensory neurons in the adipose tissue to observe what happened.
Through this, researchers discovered that nearly half of these neurons didn’t connect to the sympathetic nervous system — the network of nerves that helps your body mobilize its “fight-or-flight” response — but instead, Science Daily reported, to the dorsal root ganglia — “an area of the brain where all sensory neurons originate,” which are responsible for firing and sending off signals to the rest of the nervous system about the information they have received.
When sensory neuron communication was silenced, the sympathetic nervous system began converting the white fat cells into brown fat, which can then burn calories through a process called thermogenesis and speeds up the body’s fat-burning processes.
Before the study, researchers believed the nerves in fat belonged mostly to the sympathetic nervous system and switched on fat-burning pathways when the body was stressed or when exercising.
Now, they speculate two opposing nerve signals may work together with the sympathetic nervous system to switch the fat-burning processes on while the sensory neuron pathway turns the process off.
“This tells us that there’s not just a one-size-fits-all instruction that brain sends adipose tissue,” explained Ye. “It’s more nuanced than that; these two types of neurons are acting like a gas pedal and a brake for burning fat.”
In mammals, adipose tissue stores energy in the form of fat cells and releases those stores when the body needs energy, also controlling hormones and signaling molecules related to hunger and metabolism. Energy storage and signaling are often mixed up in diseases like diabetes, fatty liver disease, atherosclerosis and obesity.
“The team doesn’t yet know exactly what messages the sensory neurons convey to the brain from adipose tissue, only that the connections and communications are key for keeping fat healthy,” explained Science Daily.