Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Brain’s On-Off Thirst Switch Identified

27.01.2015

Findings could lead to new therapies for dehydration and excessive thirst.

Neurons that trigger our sense of thirst—and neurons that turn it off—have been identified by Columbia University Medical Center neuroscientists. The paper was published today in the online edition of Nature.


Lab of Charles Zuker

CUMC researchers have identified two types of neurons that control thirst. This image of a mouse brain shows the two neurons, CAMKII (in red) that triggers thirst and VGAT (in green) that inhibit thirst.

For years, researchers have suspected that thirst is regulated by neurons in the subfornical organ (SFO), in the hypothalamus. But it has been difficult to pinpoint exactly which neurons are involved. “When researchers used electrical current to stimulate different parts of the SFO of mice, they got confusing results,” said lead author Yuki Oka, PhD, a postdoctoral research scientist in the laboratory of Charles S. Zuker, PhD, professor of biochemistry and molecular biophysics and of neuroscience, a member of the Kavli Institute for Brain Science and the Mortimer B. Zuckerman Mind Brain Behavior Institute, and a Howard Hughes Medical Institute Investigator at CUMC.

The CUMC team hypothesized that there are at least two types of neurons in the SFO, including ones that drive thirst and others that suppress it. “Those electrostimulation experiments were probably activating both types of neurons at once, so they were bound to get conflicting results,” said Yuki Oka.

To test their hypothesis, Drs. Oka and Zuker turned to optogenetics, a more precise technique for controlling brain activity. With optogenetics, researchers can control specific sets of neurons in the brain after inserting light-activated molecules into them. Shining light onto these molecules turns on the neurons without affecting other types of neurons nearby.

These “mind-control” experiments revealed two types of neurons in the SFO that control thirst: CAMKII neurons, which turn thirst on, and VGAT neurons, which turn it off.

When the researchers turned on CAMK11 neurons, mice immediately began to seek water and to drink intensively. This behavior was as strong in well-hydrated mice as in dehydrated ones. Once the neurons were shut off—by turning off the light—the mice immediately stopped drinking.

The researchers also found that light-stimulation of the CAMKII neurons did not induce feeding behavior. In addition, light-induced thirst was specific for water and did not increase the animals’ consumption of other fluids, including glycerol and honey.

Similar experiments with VGAT neurons showed that these neurons act to turn off thirst. When the researchers turned on these neurons with light, dehydrated mice immediately stopped drinking, even if they were drinking water. “Together, these findings show that the SFO is a dedicated brain system for thirst,” said Dr. Oka.

“The SFO is one of few neurological structures that is not blocked by the blood-brain barrier—it’s completely exposed to the general circulation,” said Dr. Oka. “This raises the possibility that it may be possible to develop drugs for conditions related to thirst.

The article is titled, “Thirst Driving and Suppressing Signals Encoded by Distinct Neural Populations in the Brain.” The other contributor is Mingye Ye, also a postdoctoral fellow in Zuker’s lab at CUMC.

The authors declare no financial or other conflicts of interest.

The study was funded by the Howard Hughes Medical Institute and grants from the NIH (1R01NS076774, 1R01DA035025) to Professor Zuker. Dr. Oka recently moved to the California Institute of Technology as a newly appointed assistant professor.

Columbia University Medical Center provides international leadership in basic, preclinical, and clinical research; medical and health sciences education; and patient care. The medical center trains future leaders and includes the dedicated work of many physicians, scientists, public health professionals, dentists, and nurses at the College of Physicians and Surgeons, the Mailman School of Public Health, the College of Dental Medicine, the School of Nursing, the biomedical departments of the Graduate School of Arts and Sciences, and allied research centers and institutions. Columbia University Medical Center is home to the largest medical research enterprise in New York City and State and one of the largest faculty medical practices in the Northeast. For more information, visit cumc.columbia.edu or columbiadoctors.org

Contact Information
Karin Eskenazi, 212-342-0508, ket2116@columbia.edu

Karin Eskenazi | newswise

Further reports about: Arts and Sciences CUMC Switch drinking experiments neurons optogenetics

More articles from Life Sciences:

nachricht One step closer to reality
20.04.2018 | Max-Planck-Institut für Entwicklungsbiologie

nachricht The dark side of cichlid fish: from cannibal to caregiver
20.04.2018 | Veterinärmedizinische Universität Wien

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Spider silk key to new bone-fixing composite

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.

Im Focus: Writing and deleting magnets with lasers

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...

Im Focus: Gamma-ray flashes from plasma filaments

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...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

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...

Im Focus: Like a wedge in a hinge

Researchers lay groundwork to tailor drugs for new targets in cancer therapy

In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Magnetic nano-imaging on a table top

20.04.2018 | Physics and Astronomy

Start of work for the world's largest electric truck

20.04.2018 | Interdisciplinary Research

Atoms may hum a tune from grand cosmic symphony

20.04.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>