Navigation Links
Machinery of the 'marijuana munchies'

Marijuana--or more specifically its active ingredient, tetrahydrocannabinol--has a well-documented tendency to stimulate hunger. And while scientists have traced this property to cannabinoid receptors in the brain, they have had little understanding of the neural circuitry underlying this effect.

Understanding this circuitry has important practical implications because blocking the cannabinoid receptor, CB1, offers a promising approach to treating obesity. One such compound, rimonabant (trade name AcompliaTM) is already undergoing clinical testing.

In an article in the December 22, 2005, issue of Neuron, Young-Hwan Jo and colleagues report how the circuitry of CB1 is integrated with signaling by the appetite-suppressing hormone leptin. The CB1 receptor is normally triggered by natural regulatory molecules, called endocannabinoids.

In their studies, the researchers concentrated on the lateral hypothalamus (LH) of the brain, known to be a center of control of food intake. Their studies involved detailed electrophysiological measurements of the effects of specific neurons that they had identified in previous studies as being important in endocannabinoid signaling.

Their studies revealed that activation of CB1 receptors, as by endocannabinoid molecules, induced these neurons to be rendered more excitable by a mechanism called "depolarization-induced suppression of inhibition" (DSI).

What's more, they found that leptin inhibits DSI. However, they found that leptin did not interfere with the CB1 receptors themselves. Rather, leptin "short-circuits" the endocannabinoid effects by inhibiting pore-like channels in the neurons that regulate the flow of calcium into the neurons. Such calcium is necessary for the synthesis of endocannabinoids.

In further studies of mice genetically altered to be leptin deficient, the researchers found the DSI to be more prolonged than in normal mice. Thus, they said, the findings "i mplicate this mechanism for leptin receptor/endocannabinoid signaling in contributing to the maintenance of weight balance?" The researchers also included that "upregulation of endocannabinoid signaling in the LH may explain, at least in part, the increased body weight consistent with a prior report of elevated endocannabinoids" in such leptin-deficient mice.

The researchers concluded that their findings "are consistent with the hypothesis that the integration of endocannabinoid and leptin signaling regulates the excitability of neurons on appetite-related circuits."

They also wrote that "the cellular mechanisms of recently developed antiobesity drugs, such as rimonabant, may include decreased endocannabinoid signaling and hence decreased excitability of LH circuits related to appetite, even in the context of leptin insufficiency or resistance."


'"/>

Source:Cell Press


Related biology news :

1. Scientists ID molecular switch in liver that triggers harmful effects of saturated and trans fats
2. Scientists Replicate Hepatitis C Virus in Laboratory
3. Scientists detect probable genetic cause of some Parkinsons disease cases
4. Scientists find missing enzyme for tuberculosis iron scavenging pathway
5. Scientists seek answers on what activates deadly anthrax spores
6. Yale Scientists Find MicroRNA Regulates Ras Cancer Gene
7. Scientists collaborate to assess health of global environment
8. Scientists decipher genome of fungus that can cause life-threatening infections
9. Scientists discover the cellular roots of graying hair
10. Scientists rid stem cell culture of key animal cells
11. Scientists develop new color-coded test for protein folding
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:4/13/2017)... SANTA MONICA, Calif. , April 13, 2017 /PRNewswire/ ... New York will feature emerging and ... Innovation Summits. Both Innovation Summits will run alongside the ... variety of speaker sessions, panels and demonstrations focused on ... east coast,s largest advanced design and manufacturing event will ...
(Date:4/11/2017)... , April 11, 2017 No ... but researchers at the New York University Tandon ... of Engineering have found that partial similarities between ... systems used in mobile phones and other electronic ... The vulnerability lies in the fact ...
(Date:4/5/2017)... YORK , April 5, 2017 Today ... is announcing that the server component of the HYPR ... known for providing the end-to-end security architecture that empowers ... HYPR has already secured over 15 million ... makers including manufacturers of connected home product suites and ...
Breaking Biology News(10 mins):
(Date:9/20/2017)... TX (PRWEB) , ... September ... ... LLC (IPS), a leading global provider of engineering, architecture, project controls, construction ... of prefabricated cleanrooms, today announced the unveiling of the iCON™ brand which ...
(Date:9/20/2017)... Texas (PRWEB) , ... September 20, 2017 , ... From ... cell therapy succeeded after standard medicine failed. Many of these people had lost all ... Not Regression Free Download (pdf) , “Neil takes readers ...
(Date:9/19/2017)... (PRWEB) , ... September 19, 2017 , ... ... and accurately automates the most dangerous step of sample prep for metals digestion—the ... to provide automation at an affordable price. The system is ideal for any ...
(Date:9/19/2017)... ... ... CEO and founder, Dr. Bob Harman DVM, MPVM, is featured in an interview with Dr. ... Dr. Harman and Dr. Riordan met in 2003 and have remained in contact over ... cell therapy and a fast friendship was formed. , Dr. Harman has been a leader ...
Breaking Biology Technology: