When people think about a juicy burger or a cold beer, a vivid picture pops into their mind. That picture can push them to eat or drink.
Usually this link between thought and action helps us get the things we need. But sometimes the link goes wrong. It can turn into overeating, obesity, or alcohol abuse.
Scientists have known for decades that strong mental images are tied to drug use. New research on weight‑loss medicines is giving us fresh clues about why.
Drugs such as Ozempic and Wegovy copy a natural hormone called GLP‑1. They make the body release insulin, slow down digestion, and create a feeling of fullness. They were first made for type‑2 diabetes because they keep blood sugar steady.
A side effect is big weight loss – sometimes as much as surgery would achieve.
Even more interesting, people on GLP‑1 drugs often drink less alcohol. Animal studies also show they may lower the use of cocaine, amphetamines, opiates, and nicotine.
These findings are reshaping how we think about the brain’s reward system and could lead to new ways to treat obesity and addiction.
How the brain handles rewards
The brain’s “reward circuit” includes areas that release dopamine, a feel‑good chemical. The ventral tegmental area (VTA) and the nucleus accumbens (NAc) are the classic spots scientists study.
However, these regions have very few GLP‑1 receptors, so they likely aren’t where Ozempic works directly.
Researchers are looking farther upstream, at a structure called the lateral septum. This part of the brain has long been linked to emotions.
In the 1950s, scientists noticed that damaging the lateral septum made animals more aggressive, while stimulating it calmed them down.
Modern work shows the lateral septum sits in a big network that connects to many other brain areas.
The brain’s reward control center
The lateral septum receives most of its input from the hippocampus, the region that stores long‑term memories and contains “place cells” that track where we are in space and time.
Recent studies discovered that the lateral septum also has its own place cells, but they fire strongly when a reward is expected. In other words, this area adds “what’s good here” to the “where and when” information from the hippocampus.
These reward signals are then passed to dopamine‑producing regions, helping us feel pleasure.
Importantly, the lateral septum is packed with GLP‑1 receptors. Experiments that activate GLP‑1 directly in this region make mice eat less and drink less alcohol.
Our own lab found that GLP‑1 medicines calm down certain activity in the lateral septum, which may reduce its ability to drive cravings.
All of this points to the lateral septum as a key hub where cravings are formed and where GLP‑1 drugs can intervene.
