Funny & Facts

Looking one cell at a time in the brain to better understand pain, learning, memory

Working with units of material so small that it would take 50,000 to make up one drop, scientists are developing the profiles of the contents of individual brain cells in a search for the root causes of chronic pain, memory loss and other maladies that affect millions of people.

They described the latest results of this one-by-one exploration of cells or "neurons" from among the millions present in an animal brain at the 244^th National Meeting & Exposition of the American Chemical Society (ACS).

Jonathan Sweedler, Ph.D., a pioneer in the field, explained in a talk at the meeting that knowledge of the chemistry occurring in individual brain cells would provide the deepest possible insights into the causes of certain diseases and could point toward new ways of diagnosis and treatment. Until recently, however, scientists have not had the technology to perform such neuron-by-neuron research.

"Most of our current knowledge about the brain comes from studies in which scientists have been forced to analyze the contents of multiple nerve cells, and, in effect, average the results," Sweedler said. He is with the University of Illinois at Urbana-Champaign and also serves as editor-in-chief of Analytical Chemistry. "That approach masks the sometimes-dramatic differences that can exist even between nerve cells that are shoulder-to-shoulder together. Suppose that only a few cells in that population are changing, perhaps as a disease begins to take root or starts to progress or a memory forms and solidifies. Then we would miss those critical changes by averaging the data."

However, scientists have found it difficult to analyze the minute amounts of material inside single brain cells. Those amounts are in the so-called "nanoliter" range, units so small that it would take 355 billion nanoliters to fill a 12-ounce soft-drink can. Sweedler's group spent much of the past decade developing the technology to analyze the chemicals found in individual cells — a huge feat with a potentially big pay-off. "We are using our new approaches to understand what happens in learning and memory in the healthy brain, and we want to better understand how long-lasting, chronic pain develops," he said.

The 85 billion neurons in the brain are highly interconnected, forming an intricate communications network that makes the complexity of the Internet pale in comparison. The neural net's chemical signaling agents and electrical currents orchestrate a person's personality, thoughts, consciousness and memories. These connections are different from person to person and change over the course of a lifetime, depending on one's experiences. Even now, no one fully understands how these processes happen.

To get a handle on these complex workings, Sweedler's team and others have zeroed in on small sections of the central nervous system ― the brain and spinal cord ― using stand-ins for humans such as sea slugs and laboratory rats. Sweedler's new methods enable scientists to actually select areas of the nervous system, spread out the individual neurons onto a glass surface, and one-by-one analyze the proteins and other substances inside each cell.

One major goal is to see how the chemical make-up of nerve cells changes during pain and other disorders. Pain from disease or injuries, for instance, is a huge global challenge, responsible for 40 million medical appointments annually in the United States alone.

Sweedler reported that some of the results are surprising, including tests on cells in an area of the nervous system involved in the sensation of pain. Analysis of the minute amounts of material inside the cells showed that the vast majority of cells undergo no detectable change after a painful event. The chemical imprint of pain occurs in only a few cells. Finding out why could point scientists toward ways of blocking those changes and in doing so, could lead to better ways of treating pain.

More information:

Abstract

In the postgenomic era, one expects the suite of chemical players in a brain region to be known and their functions uncovered. The enormous biochemical complexity of nervous system, where even adjacent cells often have very different and dynamic metabolic profiles, necessitates development and application of technologies capable of characterizing the neurometabolome on the individual cell level. Here select brain tissues are sampled, their cells distributed on a slide and the cell locations determined. Next, the individual cells are interrogated via mass spectrometry imaging and their chemical profiles determined. Rare cells are found, and because most of the material remains on the target, these can be selected for information-rich follow-up studies. After a subtle biological perturbation, only a few cells in a large cell population respond; using this mass spectrometry imaging approach, such cells are located and characterized.

Provided by American Chemical Society

"Looking one cell at a time in the brain to better understand pain, learning, memory." August 21st, 2012.http://medicalxpress.com/news/2012-08-cell-brain-pain-memory.html

Posted by
Robert Karl Stonjek

Financial crisis to blame for increased number of suicides in Italy

(Medical Xpress) -- The global financial crisis has contributed to an increase in the rates of suicide and attempted suicide for economic reasons in Italy, new research shows.

A team of researchers, co-led by Roberto De Vogli, associate professor of health behavior and health education at the University of Michigan School of Public Health,

looked at data from 2000-10 and found an increase in suicides and attempted suicides for economic reasons during the entire period.

Using a regression model that compared time-trends for the crisis years (2008-10) against those of the pre-crisis years (2000-07), this study estimated that, between 2008 and 2010, there were 290 excess suicides and attempted suicides due to economic reasons attributable to the Great recession.

"These preliminary results have important policy implications. They suggest that, as seen in other European countries — for example, in Greece — the Great Recession and austerity packages designed to balance the budget deficit caused by the crisis, are causing significant human suffering in the general population," De Vogli said.

Research partners included Sir Michael Gideon Marmot, professor of epidemiology and public health at University College London, and David Stuckler, university lecturer in sociology, University of Cambridge. The study was partly funded by a grant from the Economic and Social Research Council.

In what the authors call "the first grassroots movement on mental health in Europe" widows of men who killed themselves had protested in May at tax offices in Bologna, Italy, claiming that, "austerity and tax collection put their husbands at risk." Yet, not all who heard their campaign believed in what some are calling "suicides by economic crisis", which prompted the team to analyze data compiled by the Italian Institute of National Statistics.

"Of course, these results need to be interpreted with caution. More research with better data is necessary to examine the impact of the crisis on suicides," De Vogli said. "However, trends in overall suicides in Italy are consistent with those of other European countries, where suicides were falling before the crisis and rapidly reversed upon the onset of the 2008 financial collapse."

De Vogli added that he and the team are in favor of prompt policy interventions to meet the social and economic needs of families and individuals who have lost their jobs, homes or business due to the 2008 financial crisis.

More information: The findings are detailed in "Excess suicides and attempted suicides in Italy attributable to the great recession," an article appears now in JECH Online First jech.bmj.com/conte… -2012-201607 and is to be published later in the print Journal of Epidemiology and Community Health.

Provided by University of Michigan

"Financial crisis to blame for increased number of suicides in Italy." August 21st, 2012. http://medicalxpress.com/news/2012-08-financial-crisis-blame-suicides-italy.html

Posted by
Robert Karl Stonjek