In mice, one gene links brain wiring to stress and metabolism

A mouse can keep eating normally and still show that its internal balance is breaking down. When researchers at the Weizmann Institute of Science switched off the Otp gene in selected cells of adult mice, the animals released extra stress hormones, showed depression-like behavior and lost much of their ability to cope with stressful challenges.

Otp, short for Orthopedia, was already known for its role before birth, when it helps create the brain’s wiring. The new study shows that its work continues in adulthood. The researchers targeted the hypothalamus, a brain region that coordinates basic functions including hunger, sleep, reproduction and stress by releasing chemical messengers that act in the brain and across the body.

The disruption reached beyond behavior. The mice had lower thyroid hormone levels, lower body temperature and higher cholesterol. They ate normally and weighed about the same as control animals, yet accumulated more body fat and responded less effectively to hunger signals. The same gene therefore appears to sit inside several systems rather than controlling a single biological pathway.

At the cellular level, the researchers describe Otp as a kind of switchboard operator. It receives signals from the body and the outside world, then helps direct DNA activity in cells involved in stress and thyroid regulation. In the hypothalamus, it can influence opposing cell populations, including those linked to hunger and energy expenditure, while helping maintain their balance.

So what changes, concretely? The study offers a biological explanation for why stress and metabolism can move together, rather than treating them as entirely separate problems. That may help researchers investigate conditions in which stress, thyroid hormones, cholesterol or blood sugar overlap. For now, the result is a laboratory finding in mice—not a human treatment—and the researchers say the gene’s role in people still needs to be established.