Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Unconventional brain circuits offer clues to insomnia-obesity connection

13.04.2005


NationaUnconventional wiring of the brain circuits that govern sleep and waking might explain the prevalence of insomnia and the condition’s association with obesity, according to new work published in the April issue of Cell Metabolism. Characterized by a chronic inability to fall asleep or remain sleeping, insomnia is estimated to affect one in every eight Americans.



By finding ways to interfere with that unconventional wiring, scientists may advance on new treatments for insomnia, the researchers said. Natural variation in this brain system might also explain differences among people in their susceptibility to sleep disturbances.

The researchers found that so-called hypocretin neurons--having important roles in both arousal and appetite--lack the ability of most neurons to filter "noise" from signal, reported Tamas Horvath and Xiao-Bing Gao of Yale University School of Medicine. The neurons also rapidly reorganize themselves, becoming even more excitable, in response to stresses such as food deprivation, they found.


"The cell bodies of most neurons act as a filter," sorting through a multitude of signals to eliminate noise and generate an appropriate response, Horvath said. "In contrast, it appears that the basic wiring of hypocretin neurons allows noise to become the major signal."

As obesity has reached epidemic proportions, the incidence of insomnia and sleep deprivation has also risen. Studies of this apparent insomnia-obesity association have suggested a causal link between the two, but the underlying mechanism has remained unclear. The new findings of hypocretin neurons offer some possible clues, Horvath said.

Scientists discovered hypocretin neurons while studying narcolepsy, a condition marked by sudden bouts of deep sleep. Narcolepsy generally stems from a shortage or malfunction of hypocretin neurons. The neurons also induce appetite, an important activity for the control of food intake. Yet the integration of the brain cells’ roles in arousal and appetite remains largely unexplored, Horvath said.

In a series of experiments in brain slices and in mice, the researchers examined the organization and stability of inputs to hypocretin cell bodies, which act as filters in other brain cells. They found that hypocretin neurons have an "unorthodox" organization in which excitatory currents exert control on nerve cell bodies with minimal inhibitory inputs to filter them.

Overnight food deprivation promoted the formation of more excitatory inputs. Those new inputs were reversed upon refeeding, they reported, an indication of the extreme plasticity of the hypocretin system to prevailing conditions.

That sensitivity and adaptability makes sense, given the neurons’ role as the body’s natural alarm, rousing one from slumber in response to external cues, Horvath said. However, the structure of the system might also explain the prevalence of sleep disorders and, perhaps, the associated rise in obesity.

"In an evolutionary sense, the response of the hypocretin system to small stimuli would have been necessary for survival," he said. "But in today’s chronically stressful environment, the circuitry may also be an underlying cause of insomnia and associated metabolic disturbances, including obesity."

Heidi Hardman | EurekAlert!
Further information:
http://www.cellmetabolism.org

More articles from Life Sciences:

nachricht Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View
22.06.2018 | University of Sussex

nachricht New cellular pathway helps explain how inflammation leads to artery disease
22.06.2018 | Cedars-Sinai Medical Center

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Graphene assembled film shows higher thermal conductivity than graphite film

22.06.2018 | Materials Sciences

Fast rising bedrock below West Antarctica reveals an extremely fluid Earth mantle

22.06.2018 | Earth Sciences

Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View

22.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>