You check into a hotel and toss and turn all night, but your sleep improves the following night. Scientists at Nagoya University wanted to understand why this happens. Working with mice, they have identified a group of neurons that become active when an animal enters a new environment. These neurons release a molecule called neurotensin that maintains wakefulness. The effect protects them from potential dangers in unknown surroundings. The study was published in Proceedings of the National Academy of Sciences.
This discovery may explain the “first night effect” seen in humans. On the first night in a new place, the brain remains more vigilant, almost as if acting as a night guard. It keeps one eye open until it confirms the environment is safe. This response evolved to enhance survival. Although this…