Disturbance of sleep in new places: Why do we have trouble sleeping in new places?
We’ve all been there: staying at a relative’s house or checking into a new hotel, only to spend the night tossing and turning. Despite the plush pillows, soft lighting, and perfect room temperature, eyes remain wide open at 3 a.m. Body is tired, bed is very comfortable, yet sleep refuses to come. For decades, scientists knew that the ‘first night effect’ was real, but the reason why the brain impaired rest in new places was unclear.Scientists at Nagoya University wanted to understand why this happens. What else? they found the reason behind it first night effect. The findings of the study have been published in the Proceedings of the National Academy of Sciences.
Why is sleep affected in new environments?
You may have noticed that, on the first day of checking in to a hotel, you keep tossing and turning the whole night. But, surprisingly, sleep improves the next night. What is the reason behind this? To understand this, researchers conducted experiments on rats. They 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. Its effect protects them from potential dangers in unknown environments.
first night effect
When you check in to a new hotel room, your brain doesn’t see a comfortable bed, it senses potential danger. The new findings may explain the ‘first night effect’ observed in humans. The brain becomes more alert on the first night in a new place. It acts as a night watchman. It keeps one eye open until it confirms that the environment is safe. This response evolved to enhance survival. Although this sleep disorder has been intensively researched for decades, the brain mechanisms behind it have remained unclear.“The extended amygdala is a brain region that processes emotions and stress in mammals. Within this region, specific neurons called the iPACL (interstitial part of the anterior central amygdala), CRF neurons, produce neurotensin and are activated when sensing a new environment. The neurotensin then influences the basal region of the brain, which controls movement and alertness,” said senior author and study author of the Environmental Medicine Research Institute of Nagoya University. said lecturer Daisuke Ono. In a release.The researchers studied rats in new cages and recorded their brain activity. They observed that iPACL CRF neurons became highly active in their new environment. To confirm the cause, the researchers artificially suppressed these neurons, and they found that the mice fell asleep quickly, despite being in a new environment. When these neurons were activated, the mice remained awake for longer periods of time. The team showed that iPACL CRF neurons use neurotensin to communicate with the substantia nigra.Researchers believe that similar circuits likely operate in humans as well, as the extended amygdala and substantia nigra are present in all mammals. These new findings may help develop new treatments for insomnia and anxiety disorders. Many people suffering from PTSD or chronic stress experience hypervigilance at night. Medications that target this neurotensin pathway can help them sleep.