(Press-News.org) ANN ARBOR—You're standing near an airport luggage carousel and your bag emerges on the conveyor belt, prompting you to spring into action. How does your brain make the shift from passively waiting to taking action when your bag appears?
A new study from investigators at the University of Michigan and Eli Lilly may reveal the brain's "switch" for new behavior. They measured levels of a neurotransmitter called acetylcholine, which is involved in attention and memory, while rats monitored a screen for a signal. At the end of each trial, the rat had to indicate if a signal had occurred.
Researchers noticed that if a signal occurred after a long period of monitoring or "non-signal" processing, there was a spike in acetylcholine in the rat's right prefrontal cortex. No such spike occurred for another signal occurring shortly afterwards.
"In other words, the increase in acetylcholine seemed to activate or 'switch on' the response to the signal, and to be unnecessary if that response was already activated," said Cindy Lustig, one of the study's senior authors and an associate professor in the U-M Department of Psychology.
The researchers repeated the study in humans using functional magnetic resonance imaging (fMRI), which measures brain activity, and also found a short increase in right prefrontal cortex activity for the first signal in a series.
To connect the findings between rats and humans, they measured changes in oxygen levels, similar to the changes that produce the fMRI signal, in the brains of rats performing the task.
They again found a response in the right prefrontal cortex that only occurred for the first signal in a series. A follow-up experiment showed that direct stimulation of brain tissue using drugs that target acetylcholine receptors could likewise produce these changes in brain oxygen.
Together, the studies' results provide some of the most direct evidence, so far, linking a specific neurotransmitter response to changes in brain activity in humans. The findings could guide the development of better treatments for disorders in which people have difficulty switching out of current behaviors and activating new ones. Repetitive behaviors associated with obsessive-compulsive disorder and autism are the most obvious examples, and related mechanisms may underlie problems with preservative behavior in schizophrenia, dementia and aging.
###
The study's other authors included William Howe, Martin Sarter, Anne Berry and Joshua Carp from U-M and Jennifer Francois, Gary Gilmour and Mark Tricklebank from Eli Lilly.
The findings appear in the current issue of Journal of Neuroscience.
Waiting for a sign? Researchers find potential brain 'switch' for new behavior
2013-05-21
ELSE PRESS RELEASES FROM THIS DATE:
JPIDS: Releases consensus statement on research definitions for drug-resistant TB in children
2013-05-21
ARLINGTON, VA, May 21, 2013—The Journal of the Pediatric Infectious Diseases Society (JPIDS) today released its June issue, which includes a consensus statement of the global Sentinel Project on Pediatric Drug-Resistant Tuberculosis. It establishes standardized definitions, measurements, and other key attributes that will effect research. This is the first step as the group of international stakeholders collaborate to raise visibility and share evidence and resources that can improve children's access to prompt and effective treatment.
Consensus Statement on Research ...
Single-cell transfection tool enables added control for biological studies
2013-05-21
Northwestern University researchers have developed a new method for delivering molecules into single, targeted cells through temporary holes in the cell surface. The technique could find applications in drug delivery, cell therapy, and related biological fields.
Bulk electroporation — a technique used to deliver molecules into cells through reversible nanopores in the cell membrane that are caused by exposing them to electric pulses — is an increasingly popular method of cell transfection. (Cell transfection is the introduction of molecules, such as nucleic acids or proteins, ...
Tiny, implantable coil promises hope for emphysema patients
2013-05-21
ATS 2013, PHILADELPHIA ─ A small, easily implantable device called the Lung Volume Reduction Coil (LVRC) may play a key role in the treatment of two types of emphysema, according to a study conducted in Europe. Results of the study indicate the beneficial effects of the device persist more than a year after initial treatment.
The study will be presented at the ATS 2013 International Conference.
"LVRC treatment results in significant and clinically relevant improvements in lung function, ability to exercise and quality of life for patients with emphysema," said ...
Exposure to traffic pollution increases asthma severity in pregnant women
2013-05-21
ATS 2013, PHILADELPHIA ─ Air pollutants from traffic are associated with increased asthma severity levels in pregnant asthmatic women, according to a new study.
"Air pollution is a known trigger for asthma symptoms," said lead author Janneane Gent, PhD, Research Scientist in Epidemiology (Environmental Health) at the Yale School of Public Health. "In our study, exposures were assessed using a sophisticated air pollution modeling system (Community Multiscale Air Quality, CMAQ) that permits community-level estimates (i.e., close to where the subject resides) instead ...
Study finds air pollution and noise pollution increase cardiovascular risk
2013-05-21
ATS 2013, PHILADELPHIA ─ Both fine-particle air pollution and noise pollution may increase a person's risk of developing cardiovascular disease, according to German researchers who have conducted a large population study, in which both factors were considered simultaneously.
"Many studies have looked at air pollution, while others have looked at noise pollution," said study leader Barbara Hoffmann, MD, MPH, a professor of environmental epidemiology at the IUF Leibniz Research Institute for Environmental Medicine in Germany. "This study looked at both at the same ...
Prenatal exposure to traffic is associated with respiratory infection in young children
2013-05-21
ATS 2013, PHILADELPHIA ─ Living near a major roadway during the prenatal period is associated with an increased risk of respiratory infection developing in children by the age of 3, according to a new study from researchers in Boston.
"The connection between in utero and early life cigarette smoke exposure and adverse infant respiratory outcomes is well-established, but the relation of prenatal ambient air pollution to risk of infant respiratory infection is less well-studied," said lead author Mary Rice, MD, a pulmonary and critical care fellow at Massachusetts ...
Early childhood respiratory infections may explain link between analgesics and asthma
2013-05-21
ATS 2013, PHILADELPHIA ─ A new study conducted by Boston researchers reports that the link between asthma and early childhood use of acetaminophen or ibuprofen may be driven by underlying respiratory infections that prompt the use of these analgesics, rather than the drugs themselves.
The results of the new study will be presented at the ATS 2013 International Conference.
Analgesics like ibuprofen and acetaminophen are routinely given to treat fever in infants, and several studies have shown a link between the use of analgesics during infancy and the subsequent ...
Combined wood and tobacco smoke exposure increases risk and symptoms of COPD
2013-05-21
ATS 2013, PHILADELPHIA ─ People who are consistently exposed to both wood smoke and tobacco smoke are at a greater risk for developing chronic obstructive pulmonary disease (COPD) and for experiencing more frequent and severe symptoms of the disease, as well as more severe airflow obstruction, than those who are exposed to only one type of smoke, according to the results of a new population-based study conducted by researchers in Colombia.
The results of the study will be presented at the ATS 2013 International Conference.
"Although previous studies have shown ...
May/June 2013 Annals of Family Medicine tip sheet
2013-05-21
Much of the May/June 2013 issue of Annals of Family Medicine and the entirety of an accompanying supplement published in partnership with the U.S. Agency for Healthcare Research and Quality are about changing primary care practice. Practice transformation on a large scale toward the patient-centered medical home model of care is a cornerstone of health care reform efforts in the United States, and the research and commentary in this issue can serve as a roadmap to achieve practice transformation. Not only do the articles address the opportunities, challenges, costs, processes ...
Whole-cell vaccine was more effective than acellular vaccine during California pertussis outbreak
2013-05-21
OAKLAND, Calif., May 20, 2013 — Whole-cell pertussis vaccines were more effective at protecting against pertussis than acellular pertussis vaccines during a large recent outbreak, according to a new Kaiser Permanente study published in Pediatrics.
Whole-cell pertussis vaccines, also called DTwP, were available from the 1940s to 1990s, but were associated with safety concerns that ultimately led to the development of acellular pertussis vaccines, which are also called DTaP. By the late 1990s, the United States had switched from whole-cell to acellular vaccines for all ...