[Good Brain 2026] "The Blueprint of GLP-1 Unveiled...A Major Step Toward Brain Disease Applications"

Fang Zhiping, Professor at Rutgers Medical School
"GLP-1 Modulates Neural Circuits in the Brain"
"Potential for Treating Addiction and Neurological Disorders"

"Understanding GLP-1 merely as an appetite-suppressing signal is only half the explanation. The academic community is now focusing on how GLP-1 affects the very way the brain processes information, with increasing attention on its potential applications for various diseases."

Professor Fang Zhiping, Director of the Brain Metabolism Center at Rutgers Robert Wood Johnson Medical School in the United States, made these remarks during his keynote speech at the "2026 Good Brain Conference" hosted by The Asia Business Daily and held on September 3 at The Westin Chosun Hotel Seoul in Sogong-dong, Jung-gu, Seoul. Professor Fang presented research findings on the topic "Glucagon-Like Peptide-1 (GLP-1): From a Metabolic Hormone to a Brain Circuit Signal," discussing what GLP-1, widely known as an obesity treatment, actually does in the brain.

Professor Fang Zhiping from Rutgers University School of Medicine in the United States is delivering the keynote speech at the "2026 Good Brain Conference" held under the theme "Brain Revolution: The Future of Humanity Changed by GLP-1" on the 3rd at the Westin Chosun Hotel Seoul in Junggu, Seoul. Photo by Kang Jinhyung

GLP-1 is a hormone released from the gut after eating, which lowers blood sugar and suppresses appetite. All anti-obesity drugs currently sold worldwide are designed to mimic this hormone's function, which has led to GLP-1 being widely referred to as the "weight loss hormone." Professor Fang noted, "Such explanations still only account for half of GLP-1's story." He went on to identify GLP-1's key role as "acting on brain neurons."

Having dedicated nearly 20 years to research on "GLP-1 produced by the brain," Professor Fang explained that the location where GLP-1 is generated within our bodies deserves attention. He stated, "GLP-1 is produced not just in the gut but also directly within the brain, and the neurons responsible for this production may play a critical role in regulating the functions performed by the brain throughout the body." According to him, GLP-1 is not merely a "messenger" that transmits the feeling of satiety to the brain; rather, it acts more as a "manager" adjusting how strongly signals are transmitted within the brain itself.

Professor Fang further stressed that "GLP-1 is not just a hormone, but a neuromodulator." The difference between a hormone and a neuromodulator lies in their mechanisms of action. Hormones travel throughout the entire body via the bloodstream, delivering various instructions to different bodily elements. In contrast, neuromodulators attach to specific neural circuits in the brain, amplifying or reducing the signals that travel through those specific pathways. According to Professor Fang, GLP-1 does not simply give orders, but directly modulates the activities of various bodily functions.

Recent experiments conducted by Professor Fang's research team have clarified the pathways through which GLP-1 acts in the brain. The team used genetically modified mice designed so that specific target cells could be marked—by introducing or removing certain genes—allowing only GLP-1-producing neurons and GLP-1-receiving neurons to express fluorescent proteins. This enabled the researchers to select and observe only the target cells among millions of neurons.

The research also employed optogenetics, a technique in which light-sensitive proteins are inserted into these specific cells so that only the targeted cells are activated when exposed to blue light. The researchers artificially stimulated select circuits in this manner, then inserted microelectrodes into the receiving neurons to directly measure the intensity of transmitted signals. Professor Fang noted, “While the fact that GLP-1-based drugs lead to weight loss is well understood, the precise neural pathways within the brain responsible for this effect had not yet been elucidated. In this regard, we had the 'medicine,' but not the 'blueprint.'”

Identifying how GLP-1 functions within brain pathways could help address various side effects of current treatments. Existing GLP-1-based drugs act on receptors throughout the entire body, which means that along with weight loss effects, side effects such as nausea or indigestion can also occur. If we know which specific neural circuit leads to which outcome, it would be possible to design drugs that target only those circuits, maximizing therapeutic effects while minimizing side effects. Professor Fang stated, "Recently, multidimensional studies have been underway to unravel the various mechanisms through which GLP-1 operates in neural circuits. For instance, as we learn more about how GLP-1 functions under different disease conditions or physiological states, the potential for developing therapies using this molecule continues to expand."

He particularly emphasized that this research is not limited to obesity disorders alone. Professor Fang said, "The breakdown of signal transmission between neurons is not exclusive to obesity. Mental illnesses such as depression, as well as neurodegenerative diseases like Alzheimer's and Parkinson's, all stem from disruptions in these communications." If GLP-1 can modulate such signals, drugs initially developed for obesity could be repurposed for the treatment of brain disorders.

Professor Fang concluded, "We are entering an era in which GLP-1 should be understood not merely as a metabolic disease treatment target, but as a powerful neuromodulatory system. GLP-1 and circuit-specific neuromodulators may hold the key to transforming brain disease treatment."

This content was produced with the assistance of AI translation services.