Reining in nicotine use

MDC researchers: Midbrain habenula region plays key role in nicotine dependence

2011-05-13

(Press-News.org) A person's vulnerability to nicotine addiction appears to have a genetic basis, at least in part. A region in the midbrain called the habenula (from Latin: small reins) plays a key role in this process, as Dr. Inés Ibañez-Tallon and her team from the Max Delbrück Center for Molecular Medicine (MDC) Berlin-Buch, Germany, have now shown. They also shed light on the mechanism that underlies addiction to nicotine (Neuron, May,12, 2011, Vol. 70, Issue 3, pp: 522-535; DOI 10.1016/j.neuron.2011.04.013)*.

According to the World Health Organization WHO in Geneva, it is estimated that tobacco use kills more than five million people each year worldwide. Many of them die of lung cancer. "Two years ago, studies indicated that genetic variations in a specific gene cluster are risk factors for nicotine dependence and lung cancer," Dr. Ibañez-Tallon pointed out. She and her team, together with researchers from the Pasteur Institute in Paris, France and the Russian Academy of Sciences in Moscow, have now elucidated the mechanism underlying this dependence.

They investigated a specific receptor for the neurotransmitter acetylcholine, which is activated by nicotine in smokers and is encoded by this specific gene cluster, consisting of three subunits, that is three genes. "Although this gene cluster is present in the DNA of every cell, the receptor is only expressed in a few restricted areas of the brain. One of them is the habenula in the midbrain," Dr. Ibañez-Tallon explained.

The MDC researchers investigated this receptor and its subunits in egg cells of the African clawed frog (Xenopus laevis) and in transgenic mice. One of the three genes of the cluster is alpha5. "An important percentage of heavy smokers carry a single mutation in this gene. They are more prone to become addicted to nicotine and to develop lung cancer than individuals without this mutation," Dr. Ibañez-Tallon said.

Strong Aversion to Nicotine A second gene in the gene cluster encoding this receptor is beta4. The MDC researchers demonstrated that transgenic mice expressing high levels of the beta4 gene have increased sensitivity to nicotine. These mice have a strong aversion to drinking water containing nicotine.

However, when the researchers expressed the mutated variant of the alpha5 gene via a lentivirus in the habenular brain region of these mice, after only two weeks the mice showed a preference for nicotine. Dr. Ibañez-Tallon and her colleagues conclude that only a balanced activity of these two genes can rein in nicotine use.

### *Aversion to Nicotine Is Regulated by the Balanced Activity of b4 and a5 Nicotinic Receptor Subunits in the Medial Habenula Silke Frahm,1 Marta A. Slimak,1 Leiron Ferrarese,1 Julio Santos-Torres,1 Beatriz Antolin-Fontes,1 Sebastian Auer,1 Sergey Filkin,3 Stéphanie Pons,5 Jean-Fred Fontaine,2 Victor Tsetlin,3 Uwe Maskos,4,5 and Inés Ibañez-Tallon1,*
1Department of Molecular Neurobiology, Max-Delbrück-Centrum, Robert-Rössle-Strasse 10, 13125 Berlin, Germany
2Computational Biology and Data Mining Group, Max-Delbrück-Centrum, Robert-Rössle-Strasse 10, 13125 Berlin, Germany
3Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia
4Institut Pasteur, Unité Neurobiologie Intégrative des Systèmes Cholinergiques, Département de Neuroscience, F-75724 Paris cedex 15, France
5CNRS, URA2182, F-75724 Paris cedex 15, France
*Correspondence: ibanezi@mdc-berlin.de

Barbara Bachtler
Press Department
Max Delbrück Center for Molecular Medicine (MDC) Berlin-Buch
Robert-Rössle-Straße 10; 13125 Berlin; Germany
Phone: +49 (0) 30 94 06 - 38 96
Fax: +49 (0) 30 94 06 - 38 33
e-mail: presse@mdc-berlin.de
http://www.mdc-berlin.de/

Further information:
http://www.who.int/tobacco/statistics/tobacco_atlas/en/
http://www.who.int/tobacco/mpower/2009/a2_gtcr_report_summary.pdf
http://www.nature.com/nature/journal/v471/n7340/full/nature09797.html
http://www.cell.com/neuron/home

ELSE PRESS RELEASES FROM THIS DATE:

Eucalyptus tree genome deciphered

2011-05-13

The key to the survival of forestry in South Africa as well as many new possibilities for renewable bioproducts like biofuels and biopolymers may now be available with the click of a mouse. This follows on a team of international researchers, led by Prof Zander Myburg from the Department of Genetics and the Forestry and Agricultural Biotechnology Institute (FABI) at the University of Pretoria (UP) – in collaboration with the US Department of Energy (DOE) Joint Genome Institute (JGI) – making available the complete genome sequence of the forest tree species, Eucalyptus ...

Shaking down frozen helium: In a 'supersolid' state, it has liquid-like characteristics

2011-05-13

ITHACA, N.Y. – In a four-decade, Holy Grail-like quest to fully understand what it means to be in a "supersolid" state, physicists have found that supersolid isn't always super solid. In other words, this exotic state of frozen helium appears to have liquid-like properties, says a new paper published in the journal Science (May 13, 2011). Why is this important? Understanding supersolid helium brings us closer to understanding its close cousins superconductivity and superfluidity. Physicists had long thought that the unusual behavior of torsion oscillators containing ...

Perfect welds for car bodies

2011-05-13

This release is available in German. As if controlled by an invisible hand, the welding head on the robot's arm races along the sheet metal parts. Where the laser hits, sparks fly and the metal glows red hot. The process lasts just a few seconds. The outer door panel and the door frame are now welded together perfectly. A thin weld seam extends along the join, but it can only be seen on one side. From the other side of the welded car door the join is invisible. This is a perfect weld – the kind every car manufacturer dreams of, because it could be used anywhere on the ...

Water for Mongolia

2011-05-13

This release is available in German. Mongolia is a country of contrasts – in summer boiling hot, in winter freezing cold; in the north damp, in the south bone dry. One million of its three million inhabitants live tightly packed together in the capital Ulaanbaatar, while the rest of the huge country is largely populated by nomads and their cattle. Providing a clean supply of drinking water across the entire country is a difficult challenge – beginning with the need to lay freeze-proof water pipes over an area of 1.5 million square kilometers. The people in the countryside ...

CAMH researcher discovers new gene that causes intellectual disability

2011-05-13

May 13, 2010 – (Toronto) – A new study involving Canada's Centre for Addiction and Mental Health (CAMH) has found a gene connected with a type of intellectual disability called Joubert syndrome. CAMH Senior Scientist Dr. John Vincent has identified this gene that, when defective, leads to Joubert syndrome. This research is published in the 13 May 2011 issue of Cell. This international study combined Dr. Vincent's gene mapping of a family with Joubert syndrome, with the use of a protein network map established by researchers at Genentech Inc., Stanford University and ...

The Importance of Putting Your Children First in Texas Divorce Cases

2011-05-13

Putting yourself first in a divorce proceeding is tempting. Whenever a husband (dad) and wife (mom) decide to dissolve their marriage, the heartache can be overwhelming. Of course, the torrent of emotional and legal problems multiplies exponentially when children are involved. Your adult problems will impact innocent and precious people who did not have a voice in your decision to give them two separate homes. Child custody (or child conservatorship as it is called in Texas) becomes one of the most important areas to resolve when finalizing the divorce details. With knowledge ...

Underage Alcohol Possession And Consumption In Virginia

2011-05-13

As the Centers for Disease Control describe it, "Alcohol use by persons under age 21 years is a major public health problem." While illegal for those under 21, the statistics indicate substantial use by many minors. - 42% drank some amount of alcohol. - 24% binge drank. - 10% drove after drinking alcohol. - 28% rode with a driver who had been drinking alcohol. Virginia Laws Related to Underage Drinking The Commonwealth of Virginia has very strict laws and severe punishment for underage possession and consumption of any alcohol. - It is illegal for anyone ...

Common Birth Injuries and Their Causes

2011-05-13

Some birth injuries are relatively minor health concerns that heal within a few days or weeks, while others are significant medical events that can carry life-long consequences for children and their parents. Sometimes no one is at fault for a birth injury that occurred during labor or delivery. However, other birth injuries result from the negligence of doctors, nurses or other medical-care providers. Reduced Oxygen Reduced oxygen is one of the main causes of brain injuries during labor and delivery. When a baby's oxygen supply is reduced or blocked, brain damage ...

Florida Changes Its Slip-and-Fall Law

2011-05-13

The state of Florida has made it significantly more difficult for plaintiffs to prevail in slip-and-fall cases. If you or a member of your family has suffered an injury, contact a slip and fall attorney for an evaluation of the facts of the case. The Old Law Compared to the New Law The old premises liability law simply required plaintiffs to prove that an accident had taken place. The new law, which went into effect on July 1, requires plaintiffs to prove that a defendant knew of the conditions that resulted in the accident. Plaintiffs have another avenue to ...

Possible Recognition of Parental Alienation Syndrome Controversial

2011-05-13

As everyone knows, divorces can often be contentious. Add children to the mix, and it can heighten the animosity, as both parents strive to do what they feel is best for the children. Sometimes these efforts boil over into accusations that the other parent is "bad" in some way -- eventually causing the child to share one parent's dislike for the other. In extreme cases, children have become unfairly estranged from one of their parents as a result. Over the past 30 years, a name has emerged for this sort of situation -- parental alienation syndrome. Those who ...

Identification of chemical constituents and blood-absorbed components of Shenqi Fuzheng extract based on UPLC-triple-TOF/MS technology

Emergency department physicians vary widely in their likelihood of hospitalizing a patient, even within the same facility

Firearm and motor vehicle pediatric deaths— intersections of age, sex, race, and ethnicity

[Press-News.org] Reining in nicotine use
MDC researchers: Midbrain habenula region plays key role in nicotine dependence

Reining in nicotine use

ELSE PRESS RELEASES FROM THIS DATE:

LAST 30 PRESS RELEASES: