An investigation into sleep in fish could open avenues for treating insomnia in humans

Santiago de Compostela.- A study on sleep in zebrafish has identified a hitherto unknown brain circuit that acts as a "biological button", a mechanism that can open ways to treat insomnia in humans, the Spanish National Research Council (CSIC) reported this Wednesday. The research, published by the scientific journal "Current Biology" and in which scientists from several countries participated, including the Marine Research Institute of the CSIC, analyzed the activity of a group of neurons in the hypothalamus of zebrafish larvae, a species used by scientists in the field of biomedicine for sharing similarities with the human brain. In this analysis, the researchers identified new neurons that express the Qrfp and Pth4 genes as promoters of sleep in fish, the CSIC points out in a statement. The neuropeptide Pth4 is responsible for activating the sleep promotion mechanism through a double system, which includes the inhibition of wakefulness-driving neurons and the potentiation of those that favor rest, specifies the CSIC. We recommend reading:

Genetic Editing Techniques

Researchers used gene editing techniques to examine zebrafish lacking the neuropeptide Qrfp or Pth4, with the aim of determining the effects of each on sleep. The study found that these neurons "do not act in isolation" but rather "communicate with other deep regions of the brain through neurotransmitters such as norepinephrine and serotonin, which allows the brain to progressively transition from wakefulness to sleep, in a process much more dynamic and coordinated than previously thought," according to CSIC researcher Josep Rotllant. Furthermore, they observed that these neurons are especially activated when the fish stays awake for long periods of time, forming part of the system that measures the accumulated need for rest -points out the CSIC-, a mechanism that guarantees the transition to sleep at critical moments, protecting vital functions of memory, cell repair and energy regulation. Rotllant warns that although "humans do not possess exactly the same molecule" as those fish, that system could show "an ancient evolutionary system, shared between different species" capable of "saving energy and maintaining the balance of the organism." In that sense, understanding how that mechanism works "could open new avenues for treating insomnia and other sleep disorders" in humans, according to the researcher.