Navigation Links
Modulation of inhibitory output is key function of antiobesity hormone
Date:7/13/2011

Scientists have known for some time that the hormone leptin acts in the brain to prevent obesity, but the specific underlying neurocircuitry has remained a mystery. Now, new research published by Cell Press in the July 14 issue of the journal Neuron reveals neurobiological mechanisms that may underlie the antiobesity effects of leptin.

"Leptin is a hormone that is secreted by fat cells and acts at its receptor in the brain to decrease food intake and promote energy expenditure," explains senior study author Dr. Bradford B. Lowell from Beth Israel Deaconess Medical Center and Harvard Medical School. "However, despite intensive investigation, the underlying mechanisms responsible for this are poorly understood, in part due to incomplete knowledge regarding leptin-responsive neurons."

Previous studies by Dr. Lowell's group and others pinpointed a region of the brain called the arcuate nucleus as the site of key components related to the control of obesity. In particular, pro-opiomelanocortin (POMC) neurons, which have been shown to play a key role in appetite suppression, reside in this region. Although many POMC neurons express receptors for leptin, direct action of leptin on POMC neurons has not been shown to play a large role in controlling body weight. This suggests that there are likely to be other leptin-responsive neurons that are critical for leptin's antiobesity actions.

In the current study, Dr. Lowell and colleagues took a new approach for identifying these "unidentified" body weight-regulating neurons and investigated whether leptin's effects are mediated primarily by excitatory (glutamate) or inhibitory (GABA) neurons. "Remarkably, we found that leptin's antiobesity effects are mediated predominantly by GABA neurons and that glutamate neurons play only a small role," says Dr. Linh Vong, a first author on the study. Importantly, the GABA neurons are "upstream" of the POMC neurons and, in response to leptin, the GABA neurons are less active. Conversely, a reduction in leptin levels, such as occurs with fasting, increases the activity of these GABA neurons.

Taken together, the findings suggest that modulation of GABA output is a key aspect of leptin action. "Leptin working directly on GABA neurons reduces inhibitory tone to POMC neurons," concludes Dr. Lowell. "As POMC neurons prevent obesity, their disinhibition by leptin action on upstream GABA neurons likely mediates, at least in part, leptin's antiobesity effects. Further, indirect regulation of POMC neurons by leptin reconciles the known important role of POMC neurons in regulating body weight with the relatively unimportant role played by direct action of leptin on POMC neurons."


'/>"/>

Contact: Elisabeth (Lisa) Lyons
elyons@cell.com
617-386-2121
Cell Press
Source:Eurekalert

Related biology technology :

1. Neurologix Presents One-Year Follow-Up Data From Phase 2 Study of NLX-P101 in Parkinsons Disease at International Neuromodulation Society 10th World Congress
2. Victhom Human Bionics Receives CE Mark for the Neurostep(TM) System, the Worlds First Fully Implantable Closed-Loop Neuromodulation Therapy for Treatment of Foot Drop
3. Chinas Research Output More Than Doubled Since 2004, Thomson Reuters Study Reveals
4. Despite Decline in Share of Global Output, U.S. Science Impact Still Strong, Says Thomson Reuters
5. Molecular Devices Enables Intuitive Functionality at Your Fingertips on the Apple iPad with the Latest SoftMax Pro Software
6. Rhythms RM-131 Restores GI Function as a Potent Ghrelin Prokinetic
7. Functional Nutriments Awarded Federal Grant to Apply Its Dog Nutraceutical Research to Human Cancer
8. Creating Functional Hepatic Tissue in a Bioengineered Human Liver
9. Tengion Presents New Large Animal Data Demonstrating Functional Kidney Regeneration at the American Society for Transplantation Annual Conference
10. NephRx Corp. Receives Orphan Drug Designation for NX001 for Prevention of Delayed Kidney Graft Function
11. Prostate cancer risk variant found to be in a functional DNA sequence linked with disease
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/19/2017)... ... April 19, 2017 , ... ... financing round. This event adds to several other early achievements at ThermaGenix, including ... Scientific Teams. , ThermaGenix will use proceeds from the Series A-1 ...
(Date:4/19/2017)... and PUNE, India , April 19, 2017 /PRNewswire/ ... "Membrane Microfiltration Market: Global Opportunity Analysis and Industry Forecast, 2014-2022 ," the global ... $12,858 million by 2022, registering a CAGR of 9.6% from 2016 to 2022. ... ... ...
(Date:4/19/2017)... SOUTH SAN FRANCISCO, Calif. , April 19, ... VCYT ) today announced that it ... after close of market on Wednesday, May 3, 2017. ... call and webcast at 4:30 p.m. Eastern Time to discuss ... The live webcast and subsequent replay may ...
(Date:4/18/2017)... ... April 18, 2017 , ... ... awarded Channel Partners 2017 Next-Gen Solution Provider. , Channel Partners program recognizes IT ... with their vision, innovation, and advocacy of the channel during transition and convergence. ...
Breaking Biology Technology:
(Date:4/18/2017)... , April 18, 2017  Socionext Inc., a global expert ... a media edge server, the M820, which features the company,s hybrid ... software provided by Tera Probe, Inc., will be showcased during the ... the NAB show at the Las Vegas ... ...
(Date:4/11/2017)... Fla. , April 11, 2017 ... and secure authentication solutions, today announced that it ... Intelligence Advanced Research Projects Activity (IARPA) to develop ... Thor program. "Innovation has been a ... IARPA,s Thor program will allow us to innovate ...
(Date:4/6/2017)... 6, 2017 Forecasts by Product ... Readers, by End-Use (Transportation & Logistics, Government & Public ... & Fossil Generation Facility, Nuclear Power), Industrial, Retail, Business ... Are you looking for a definitive report on ... ...
Breaking Biology News(10 mins):