It Always Creeps Me Out...

(Image caption: The empty stomach releases the hormone called ghrelin. By receiving ghrelin, the hypothalamus in the brain senses hunger and produces “hunger signaling” through the action of neuropeptide Y (NPY). The hunger signaling activates neurons in the reticular formation of the medulla oblongata, which then inhibit sympathetic output to reduce metabolic heat production and simultaneously provide masticatory motor rhythm to facilitate feeding. Credit: © 2017 Yoshiko Nakamura)

New Insights into Brain Circuit for Hunger Responses during Starvation

The human body responds to starving conditions, such as famine, to promote the chance of survival. It reduces energy expenditure by stopping heat production and promotes feeding behavior. These “hunger responses” are activated by the feeling of hunger in the stomach and are controlled by neuropeptide Y (NPY) signals released by neurons in the hypothalamus. However, how NPY signaling in the hypothalamus elicits the hunger responses has remained unknown.

Sympathetic motor neurons in the medulla oblongata are responsible for heat production by brown adipose tissue (BAT). Researchers centered at Nagoya University have now tested whether the heat-producing neurons respond to the same hypothalamic NPY signals that control hunger responses. They injected NPY into the hypothalamus of rats and tested the effect on heat production. Under normal conditions, blocking inhibitory GABAergic receptors or stimulating excitatory glutamatergic receptors in the sympathetic motor neurons induced heat production in BAT. After NPY injection, stimulating glutamatergic receptors did not produce heat, but inhibiting GABAergic receptors did. The study was reported in Cell Metabolism.

“This indicated that hypothalamic NPY signals prevent BAT thermogenesis by using inhibitory GABAergic inputs to sympathetic motor neurons,” study lead author Yoshiko Nakamura says.

Retrograde and anterograde tracing with fluorescent dyes revealed which brain region provided the inhibitory GABAergic inputs to heat-producing motor neurons.

“Tracing experiments showed that sympathetic motor neurons are directly innervated by GABAergic inputs from reticular nuclei in the medulla oblongata,” corresponding author Kazuhiro Nakamura explains, “selective activation of these GABAergic reticular neurons inhibits BAT thermogenesis.”

The researchers’ further findings showed that GABAergic inputs from medullary reticular neurons are involved in hypothalamic NPY-mediated inhibition of heat production in BAT. This hunger response circuit probably explains why anorexic individuals suffer from hypothermia.

Interestingly, stimulation of these medullary reticular neurons prompted rats to begin chewing and feeding. This effect was similar to injecting NPY into the hypothalamus, suggesting that hypothalamic NPY signaling activates reticular neurons in the medulla oblongata to promote feeding and mastication during the hunger response.

Abnormal activation of these neurons under non-starved conditions may contribute to obesity. Understanding these mechanisms could lead to development of more effective treatments for obesity.

Acting outrageous and making a complete fool of yourself while drunk has been linked to a genetic mutation. It blocks the production of one of the body’s serotonin receptors, which can affect mood swings, impulsive behavior, and decision making. So far, the mutation has only been found in Finnish people, but the discovery is helping researchers understand more about the role serotonin plays in your body. Source Source 2

Physicists Detect Gravitational Waves, Proving Einstein Right

On Thursday (Feb. 11, 2016) at 10:30 a.m. ET, the National Science Foundation will gather scientists from Caltech, MIT and the LIGO Scientific Collaboration in Washington D.C. to update the scientific community on the efforts being made by the Laser Interferometer Gravitational-wave Observatory (LIGO) to detect gravitational waves.

But why is this exciting? And what the heck are “gravitational waves”?

Keep reading

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Some intriguing exoplanets

An exoplanet or extrasolar planet is a planet that orbits a star other than the Sun. The first scientific detection of an exoplanet was in 1988. However, the first confirmed detection came in 1992; since then, and as of 1 April 2017, there have been 3,607 exoplanets discovered in 2,701 planetary systems and 610 multiple planetary systems confirmed.

1- Kepler-186f

was the first rocky planet to be found within the habitable zone – the region around the host star where the temperature is right for liquid water. This planet is also very close in size to Earth. Even though we may not find out what’s going on at the surface of this planet anytime soon, it’s a strong reminder of why new technologies are being developed that will enable scientists to get a closer look at distant worlds.

2- CoRoT 7b

The first super-Earth identified as a rocky exoplanet, this planet proved that worlds like the Earth were indeed possible and that the search for potentially habitable worlds (rocky planets in the habitable zone) might be fruitful.

3- Kepler-22b  

A planet in the habitable zone and a possible water-world planet unlike any seen in our solar system.

4- Kepler 10-b

Kepler’s first rocky planet discovery is a scorched, Earth-size world that scientists believe may have a lava ocean on its surface.

5- 55 Cancri e

55 Cancri e is a toasty world that rushes around its star every 18 hours. It orbits so closely – about 25 times closer than Mercury is to our sun – that it is tidally locked with one face forever blisters under the heat of its sun. The planet is proposed to have a rocky core surrounded by a layer of water in a “supercritical” state, where it is both liquid and gas, and then the whole planet is thought to be topped by a blanket of steam.

6- 51 Pegasi b

This giant planet, which is about half the mass of Jupiter and orbits its star every four days, was the first confirmed exoplanet around a sun-like star, a discovery that launched a whole new field of exploration.

7- Kepler-444 system

The oldest known planetary system has five terrestrial-sized planets, all in orbital resonance. This weird group showed that solar systems have formed and lived in our galaxy for nearly its entire existence.

8- PSR B1257+12 system

Discovered in 1992 and 1994, the planets that orbit pulsar PSR B1257+12 are not only the smallest planetary bodies known to exist outside our solar system, they also orbit a neutron star. These weird “pulsar planets” demonstrated that planets exist in all environments in the galaxy – even around the remnants of an exploded star.

9- HD 80606 b  

This world has the most eccentric orbit, and as one scientist put it, “wears its heart on its sleeve,” with storms, rotation, atmospheric heating, and a crazy orbit all plainly visible.

10- OGLE-2005-BLG-390

Considered to be the first cold super Earth, this exoplanet began to form a Jupiter-like core of rock and ice, but couldn’t grow fast enough in size. Its final mass is five times that of Earth. The planet’s nickname is Hoth, after a planet from Star War

Credits: NASA / JPL-Caltech

Perfect magnets

Missed any of the graphics featured in C&EN? They’ve now put a page together so you can find all of the graphics in one place, on subjects including Guinness, daffodils, barbecue & more: ow.ly/RB10e

'Rollie pollies' remove heavy metals from soil, stabilizing growing conditions, protecting groundwater

'Rollie pollies' remove heavy metals from soil, stabilizing growing conditions, protecting groundwater

i’m proud of them

Does the name “Pavlov” ring any bells?

PLEASE GOD THERE IS NOTHING I NEED MORE IN MY LIFE THAN A T-REX COOING LIKE A PIGEON