Neuro researchers sharpen our understanding of memories

Scientists now have a better understanding of how precise memories are formed thanks to research led by Prof. Jean-Claude Lacaille of the University of Montreal’s Department of Physiology. “In terms of human applications, these findings could help us to better understand memory impairments in neurodegenerative disorders like Alzheimer’s disease,” Lacaille said. The study looks at the cells in our brains, or neurons, and how they work together as a group to form memories.

Chemical receptors at neuron interconnections called synapses enable these cells to form electrical networks that encode memories, and neurons are classified into two groups according to the type of chemical they produce: excitatory, who produce chemicals that increase communication between neurons, and inhibitory, who have the opposite effect, decreasing communication. “Scientists knew that inhibitory cells enable us to refine our memories, to make them specific to a precise set of information,” Lacaille explained. “Our findings explain for the first time how this happens at the molecular and cell levels.”

Many studies have been undertaken on excitatory neurons, but very little research has been done on inhibitory neurons, partly because they are very difficult to study. The scientists found that a factor called “CREB” plays a key role in adjusting gene expression and the strength of synapses in inhibitory neurons. Proteins are biochemical compounds encoded in our genes that enable cells to perform their various functions, and new proteins are necessary for memory formation. “We were able to study how synapses of inhibitory neurons taken from rats are modified in the 24 hours following the formation of a memory,” Lacaille said. “In the laboratory, we simulated the formation of a new memory by using chemicals. We then measured the electrical activity within the network of cells. In cells where we had removed CREB, we saw that the strength of the electrical connections was much weaker. Conversely, when we increased the presence of CREB, the connections were stronger.”

This new understanding of the chemical functioning of the brain may one day lead to new treatments for disorders like Alzheimer’s, as researchers will be able to look at these synaptic mechanisms and design drugs that target the chemicals involved. “We knew that problems with synapse modifications are amongst the roots of the cognitive symptoms suffered by the victims of neurodegenerative diseases,” Lacaille said. “These findings shine light on the neurobiological basis of their memory problems. However, we are unfortunately many years away from developing new treatments from this information.”

Photo: Memory (1896). Olin Warner (completed by Herbert Adams). Bronze door at main entrance of the Library of Congress Thomas Jefferson Building, Washington DC.

Speed and ecstasy associated with depression in teenagers

A five year study conducted with thousands of local teenagers by University of Montreal researchers reveals that those who used speed (meth/ampthetamine) or ecstasy (MDMA) at fifteen or sixteen years of age were significantly more likely to suffer elevated depressive symptoms the following year. “Our findings are consistent with other human and animal studies that suggest long-term negative influences of synthetic drug use,” said co-author Frédéric N. Brière of the School Environment Research Group at the University of Montreal. “Our results reveal that recreational MDMA and meth/amphetamine use places typically developing secondary school students at greater risk of experiencing depressive symptoms.” Ecstasy and speed-using grade ten students were respectively 1.7 and 1.6 times more likely to be depressed by the time they reached grade eleven.

The researchers worked with data provided by 3,880 students enrolled at schools in disadvantaged areas of Quebec. The participants were asked a series of questions that covered their drug use – what they had used in the past year or ever in their life – and their home life. Depressive symptoms were established by using a standard epidemiological evaluation tool. 310 respondents reported using MDMA (8%) and 451 used meth/amphetamines (11.6%). 584 of all respondents were identified as having elevated depressive symptoms (15.1%). The range of questions that the researchers asked enabled them to adjust their statistics to take into account other factors likely to affect the psychological state of the student, such as whether there was any conflict between the parents and the participant. “This study takes into account many more influencing factors than other research that has been undertaken regarding the association between drugs and depression in teenagers,” Brière said. “However, it does have its limitations, in particular the fact that we cannot entirely rule out the effects of drug combinations and that we do not know the exact contents of MDMA and meth/amphetamine pills.”

The study’s authors would like to do further research into how drug combinations affect a person’s likelihood to suffer depression and they are keen to learn more about the differences between adults and adolescents in this area. “Our study has important public health implications for adolescent populations,” said Jean-Sébastien Fallu, a professor at the University of Montreal and study co-author. “Our results reinforce the body of evidence in this field and suggest that adolescents should be informed of the potential risks associated with MDMA and meth/amphetamine use.”

Images: 1. Depression is also the greatest cause of high school dropouts - Martin Chamberland - La Presse. 2. Albrecht Dürer’s engraving Melencolia I, ca. 1514. Wikimedia Commons.

About this study
Frédéric N. Brière, Jean-Sébastien Fallu, Michel Janosz, and Linda S. Pagani published “Prospective associations between meth/amphetamine (speed) and MDMA (ecstasy) use and depressive symptoms in secondary school students” in the Journal of Epidemiology & Community Health on April 18, 2012. The study received funding from Fonds Québécois de Recherche sur la Santé et la Société (FQRSC, 2007-NP-112947). Frédéric Brière is affiliated with the University of Montreal’s School Environment Research Group. Jean-Sébastien Fallu is affiliated with the University of Montreal’s School Environment Research Group, School of Psycho-Education, and Public Health Research Institute. The University of Montreal is officially known as Université de Montréal.

For further information: 
William Raillant-Clark 
International Press Attaché
Université de Montréal 
Tel: 514-343-7593 
w.raillant-clark@umontreal.ca 
@uMontreal_News

Why do some pain drugs become less effective?

Researchers at the University of Montreal’s Sainte-Justine Hospital have identified how neural cells are able to build up resistance to opioid pain drugs within hours. “A better understanding of these mechanisms will enable us to design drugs that avoid body resistance to these drugs and produce longer therapeutic responses, including longer-acting opioid analgesics”, lead author Dr. Graciela Pineyro said.

Humans have known about the usefulness of opioids, which are often harvested from poppy plants, for centuries, but we have very little insight into how they lose their effectiveness in the hours, days and weeks following the first dose. “Our study revealed cellular and molecular mechanisms within our bodies that enable us to develop resistance to this medication, or what scientists call drug tolerance,” she added.

The research team looked at how drug molecules would interact with molecules called “receptors” that exist in every cell in our body. Receptors, as the name would suggest, receive “signals” from the chemicals that they come into contact with, and the signals then cause the various cells to react in different ways. They sit on the cell wall, and wait for corresponding chemicals known as receptor ligands to interact with them. Ligands can be produced by our bodies or introduced, for example, as medication.

“Until now, scientists have believed that ligands acted as ‘on-off’ switches for these receptors, all of them producing the same kind of effect with variations in the magnitude of the response they elicit,” Pineyro explained. “We now know that drugs that activate the same receptor do not always produce the same kind of effects in the body, as receptors do not always recognize drugs in the same way. Receptors will configure different drugs into specific signals that each will have different effects on the body.”

Once activated by a drug, receptors move from the surface of the cell to its interior, and once they have completed this ‘journey’, they can either be destroyed or return to the surface and used again through a process known as “receptor recycling.” By comparing two types of opioids – DPDPE and SNC-80 – the researchers found that the ligands (chemicals that enable interaction with the cell) that encouraged recycling produced less analgesic tolerance than those that didn’t. “We propose that the development of opioid ligands that favour recycling could be a way of producing longer-acting opioid analgesics,” Pineyro said.

Pineyro is attempting to tease the “painkilling” function of opioids from the part that triggers mechanisms that enable tolerance build up. “My laboratory and my work are mostly structured around rational drug design, and trying to define how drugs produce their desired and non-desired effects, so as to avoid the second, Pineyro said. “If we can understand the chemical mechanisms by which drugs produce therapeutic and undesired side effects, we will be able to design better drugs.”

Notes:

The study “Differential association of receptor-Gβγ complexes with β-arrestin2 determines recycling bias and potential for tolerance of delta opioid receptor (DOR) agonists” was published in The Journal of Neuroscience on April 3, 2012. The research was funded by the Natural Sciences and Engineering Research Council of Canada and the Canadian Institutes of Health Research. Dr. Graciela Pineyro, MD, PhD is affiliated with the Departments of Psychiatry and Pharmacology at the University of Montreal and the Sainte-Justine University Hospital Center (UHC)’ Research Center. The University of Montreal and the Sainte-Justine UHC’s Research Centre are officially known as Université de Montréal and Centre de recherche du Centre hospitalier universitaire Sainte-Justine, respectively.

Links:

• Profile of Graciela Pineyro
• Faculté de médecine de l’Université de Montréal
• Centre de recherche du CHU Sainte-Justine
• Natural Sciences and Engineering Research Council of Canada
• Canadian Institutes of Health Research

Further information and interview requests:
William Raillant-Clark
International Press Attaché
Université de Montréal
514 343-7593 - w.raillant-clark@umontreal.ca

Image: Opium users in Java during the Dutch colonial period, ca. 1870. Source: Tropenmuseum

Planning the conservation of Quebec’s northern ecosystems

The International Science Symposium: Planning the conservation of Quebec’s northern ecosystems: The challenge of a decade, to be held from April 26-27 in Montreal, will be a unique opportunity for scientists and other experts to establish a common understanding of the major conservation issues for the implementation of the government commitment to protect 50% of the territory of the Plan Nord.

The expected outcome of the symposium will be a series of questions and concrete recommendations adapted to the Québec context that will assist the government in achieving its commitment. They will identify the winning conditions for the conservation of biodiversity over large areas and the implementation of ecological planning.

The symposium will bring together international and Quebec scientists, Aboriginal and non-Aboriginal experts in community and land use planning, and natural resource conservation and management. Symposium sessions on April 26 will be open to the public (registration required), and the workshops for scientists and experts on April 27 will be by invitation only. The Symposium will be held at the Montréal Botanical Garden and the Université de Montréal Biodiversity Centre.

Symposium sponsors are the Government of Québec, the Pew Charitable Trusts, the Canadian Boreal Initiative, and The Prince Albert II Foundation of Monaco. The symposium is presented in partnership with Ducks Unlimited Canada, the International Union for the Conservation of Nature, First Nations of Labrador and Quebec Sustainable Development Institute, Université de Montréal Biodiversity Centre, and the Montréal Botanical Gardens.

For more information, see http://www.scienceqc.ca/

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Contact:
Suzanne Fraser, Canadian Boreal Initiative
613-232-2530
sfraser borealcanada.ca

© Valérie Courtois

Upcoming Health Symposium in Quebec

List prepared by the Fonds de recherche du Québec - Santé.

February 21 - 29, 2012

Canadian Digestive Diseases Week and Annual CASL Winter Meeting 2012
www.cag-acg.org

February 23 - 25, 2012
Leadership in transplantation - Annual Scientific Conference 2012
www.cst-transplant.ca

May 2 & 3, 2012
Biotech City 10th Anniversary Symposium
www.2012biotech.com

May 7 - 10, 2012
Annual Conference 2012
www.cst-transplant.ca

June 9 - 12, 2012
The Neutrophil in Immunity 2012
www.neutrophil2012.ca

June 15 - 19, 2012
CAS / SCA 2012 - 68^th Annual Meeting
www.cas.ca

June 23 - 27, 2012
11^th International Congress on Nursing Informatics 2012
www.ni2012.org

August 27 - September 4, 2012
UICC World Cancer Congress 2012
www.worldcancercongress.org

September 17 - 23, 2012
83^th Annual Meeting
www.thyroid.org

September 20 - October 3, 2012
Psychiatry 2012
www.cpa-apc.org

September 27 - 28, 2012
Annual Meeting 2012
www.orthoquebec.ca

Image: Montreal’s Palais des congrès Conference Centre. Credit: Palais des congrès

Press attaché schedule for the AAAS Annual Meeting

I am immensely proud to be representing Université de Montréal - the world’s second largest French-speaking university - at the Annual Meeting of the American Association for the Advancement of Science that is taking place in Vancouver. I am going as the university’s principle journalist liaison person for scientific research and as its press attaché for English and Foreign language media.

In case you happen to be in Vancouver for the meeting, here is part of my provisional schedule. I hope to have the opportunity to meet up with you - please don’t hesitate to drop me an email at rw.raillantclark@gmail.com.

Je suis très fier de représenter l’Université de Montréal – la deuxième plus grande du monde francophone – à l’occasion de la réunion annuelle de l’American Association for the Advancement of Science, qui se déroule actuellement à Vancouver. Je participe en tant que principal chargé des relations avec les médias pour les questions scientifiques et en tant qu’attaché de presse pour les journalistes anglophones et allophones. Au cas où vous êtes participant-e à cette réunion, je me permets de vous communiquer certains éléments de mon agenda prévisionnel ; j’espère avoir l’opportunité de vous rencontrer, donc n’hésitez pas à prendre contact avec moi par courriel à rw.raillantclark@gmail.com

Friday-Vendredi 17

• 0745 - Press Breakfast
• 0800 - Unmuzzling Government Scientists: How To Re-Open the Discourse - Une lettre en français a été publiée à ce sujet dans Le Devoir du 16 février: Science - Liberté pour les chercheurs canadiens - here is an English-version of an open letter that was published in a major newspaper about this subject.
• 1200 - Translating the Benefits of the Genetic Revolution for Humankind
• 1300 - Research Collaboration with Emerging Nations: Canada’s Experience in India and Brazil - Press release/Communiqué
• 1500 - Sharing Science with the Public Worldwide: Resources for Informal Education Outreach
• 1830 - CRDF Global Reception

Saturday-Samedi 18 

• 0800 - Global Knowledge Collaborations: The Atlas of Islamic World Science and Innovation
• 1300 - Everyone’s an Expert but Who Is Listening? 
• 1830 - AAAS International Reception and AAAS Social Media Soirée

Sunday-Dimanche 19

• 1030 - Good Science, Good Communication: Talking to the Media and the Public
• 1330 - Innovations in Reducing International Knowledge Isolation
• 1500 - Perspectives from Science Media Centers: Should Scientists Bother with Media?

Monday-Lundi 20

• 0945 - Misreporting Fukushima: A Failure of Science Journalism with Global Repercussions?

Image:Courtesy @gingerpin Ginger Pinholster. “Here is the view from [AAAS] Newsroom HQ. this is NOT photoshopped. Lucky us. #aaasmtg pic.twitter.com/KXwDycE0”