Has the elusive “sleep switch” been discovered by researchers at Oxford University’s Centre for Neural Circuits and Behaviour? A study involving fruit flies suggests the answer may be yes.
According to a summary of the article titled “Neuronal Machinery of Sleep Homeostasis in Drosophila”, the switch works by regulating the activity of a handful of sleep-promoting nerve cells, or neurons, in the brain. The neurons fire when people are tired and need sleep, and dampen down when fully rested. “When you’re tired, these neurons in the brain shout loud and they send you to sleep,” says Professor Gero Miesenböck of Oxford University.
While the research was carried out in fruit flies, or Drosophila, scientists say the sleep mechanism is likely to be relevant to humans.
Dr Jeffrey Donlea, one of the lead authors of the study, explains: “There is a similar group of neurons in a region of the human brain. These neurons are also electrically active during sleep and, like the flies’ cells, are the targets of general anaesthetics that put us to sleep. It’s therefore likely that a molecular mechanism similar to the one we have discovered in flies also operates in humans.”
The significance of the findings largely relates to the potential for pharmaceutical development, but more research is needed. “The big question now is to figure out what internal signal the sleep switch responds to,’ says Dr Diogo Pimentel of Oxford University, the other lead author of the study. “What do these sleep-promoting cells monitor while we are awake? If we knew what happens in the brain during waking that requires sleep to reset, we might get closer to solving the mystery of why all animals need to sleep.”
The findings are reported in the journal Neuron and funded by the Wellcome Trust and the Gatsby Charitable Foundation. The study was also supported by the UK Medical Research Council, the US National Institutes of Health, and the Human Frontier Science Program.