In mammals, the endogenous daily pacemaker that regulates circadian rhythms like sleep and wakefulness is localized to a defined site in the brain, the suprachiasmatic nucleus (SCN), which is composed of many neurons whose circadian activities are in synchrony with one another. By exposing rats to a very short day/night schedule – a regimen that effectively pushes the limits of the SCNs ability to set the clock to day length – researchers have discovered within the SCN two sub-clocks that normally oscillate in unison, but can become disconnected from one another as a result of artificial day/night cycles. One clock followed the artificially short 11-hr. day/11-hr. night schedule, while the other followed a longer cycle (>24 hrs.), but both clocks controlled behavioral rhythms within an individual animal.
The researchers, Horacio de la Iglesia and William Schwartz of the University of Massachusetts Medical School in Worcester, collaborating with Trinitat Cambras and Antoni Díez-Noguera of the University of Barcelona, found that the two locomotor activity rhythms reflected the separate oscillating activities of two areas within the SCN – essentially the top and bottom halves – that correspond to previously described anatomical subdivisions.
The results add to a growing awareness that it is a network of multiple oscillators, not only throughout the brain and body but also within the SCN itself, that underlies the workings of the circadian timing system. In humans, some of the symptoms arising from jet lag or rotating work schedules might not be due to the desynchronization between the central brain pacemaker and downstream oscillators in the body, but rather from the uncoupling of oscillators within the central pacemaker itself.
Heidi Hardman | EurekAlert!
Rochester scientists discover gene controlling genetic recombination rates
23.04.2018 | University of Rochester
One step closer to reality
20.04.2018 | Max-Planck-Institut für Entwicklungsbiologie
Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.
Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.
Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
23.04.2018 | Physics and Astronomy
23.04.2018 | Physics and Astronomy
23.04.2018 | Trade Fair News