Representative image
Representative image

The Interplay between sleep and wakefulness

ANI | Updated: Jul 22, 2018 19:40 IST

The Interplay between sleep and wakefulness .
Washington DC [USA] July 22 (ANI): Awake or asleep, we are basically under the regulation of two biological processes: sleep homeostasis, commonly known as 'sleep pressure', and the circadian rhythm, otherwise known as the 'body clock' .
These two processes work in harmony to promote good consolidated sleep at night .
Researchers centered at the International Institute for Integrative Sleep Medicine at Japan's University of Tsukuba revealed some neuronal pathways, which regulate sleep/wakefulness states .
The ventrolateral preoptic nucleus (VLPO) in the brain plays a critical role in falling and staying asleep, while the lateral posterior part of the hypothalamus contains neurons (brain cells) that play a role in the maintenance of staying awake .
It also includes orexin neurons in the lateral hypothalamic area (LHA) and histaminergic neurons in the tuberomammillary nucleus (TMN) .
Yuki Saito, who co-led the study said, "In our study, we aimed to identify the important players implicated in arousal regulation ."
The team used recombinant rabies-virus-mediated trans-synaptic retrograde tracing in the mouse brain to analyze the architecture and function of hypothalamic circuits that link neuronal populations implicated in sleep/wakefulness regulation .
They found that these arousal-related neurons are heavily innervated by GABAergic neurons in the preoptic area, including the VLPO .
The team further characterized GABAergic neurons in the VLPO that make direct synaptic contact with hypothalamic arousal-related neurons . hese two groups of neurons were overlapped each other, and both potently inhibited by the hormones noradrenaline and serotonin, showing typical electrophysiological characteristics of sleep-promoting neurons in the VLPO .
The full findings are present in The Journal of Neuroscience . (ANI)