Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Single genetic defect produces specific cognitive deficit in mice

07.09.2006
Researchers have found that, in mice, producing a single genetic defect in a molecule that "reloads" neurons to trigger one another using the neurotransmitter acetylcholine impairs the mice's ability to recognize objects or other mice.

The researchers, Marco Prado, Marc Caron, Vania Prado, and their colleagues, said their findings reveal a critical role in central nervous system (CNS) function for the component of the reloading machinery, called an acetylcholine transporter, that they knocked out.

They also said their findings suggest that the mouse model will be useful in understanding how defects in neurons that use acetylcholine to trigger one another contribute to cognitive decline in such disorders as Alzheimer's disease (AD) and aging. The researchers published their finding in the September 7, 2006, issue of the journal Neuron, published by Cell Press.

To explore the role of the acetylcholine transporter, the researchers genetically modified mice to either completely lack the transporter gene or to have reduced levels of it. Such transporters normally retrieve acetylcholine that one neuron has used to trigger another and transport it to storage sacs called vesicles that are the reservoir for neurotransmitter for subsequent use. The researchers found that such transporter-deficient mice were less able to fill such vesicles with acetylcholine.

In behavioral tests, the researchers found that the mice with lower levels of the transporter were less able to learn to hang on to a rotating rod than normal mice. Mice completely lacking the transporter were totally unable to manage the task because they lacked physical endurance. Thus, wrote the researchers, those mice might be useful models for studying the effects of reduced acetylcholine release in certain neuromuscular disorders.

Both normal mice and those with reduced transporter were equally able to learn and remember to avoid a mild shock. However, the reduced-transporter mice showed deficits in object recognition--significantly less able to remember that they had encountered specific-shaped plastic blocks before. The altered mice also showed less memory of "intruder" mice placed in their cages--evidence of reduced social recognition.

Significantly, the researchers found that when they used a drug to enhance acetylcholine in the transporter-deficient mice, those mice showed improved performance on social recognition tests, implying that the deficit in social recognition was caused by a reduction in "cholinergic tone."

Prado, Caron, and their colleagues concluded that "Our observations support the notion that reduced cholinergic tone in AD mouse models can indeed cause deficits in social memory. However, based on somewhat similar impairments found in the object and social recognition tasks, it is possible that mild cholinergic deficits may cause a more general memory deficit for recognizing previously learned complex cues, whether social or not. Future detailed investigations will be necessary to further define the specific type of cognitive processing affected by cholinergic deficits in these mutants.

"Such studies in mouse models of reduced cholinergic tone may be particularly informative for understanding the contribution of cholinergic decline to specific behavioral alterations observed in certain pathologies of the CNS and may even be helpful in understanding physiological aging," wrote the researchers.

Heidi Hardman | EurekAlert!
Further information:
http://www.cell.com
http://www.neuron.org

Further reports about: Neuron Recognition acetylcholine cholinergic cognitive deficit

More articles from Life Sciences:

nachricht New image of a cancer-related enzyme in action helps explain gene regulation
05.06.2020 | Penn State

nachricht Protecting the Neuronal Architecture
05.06.2020 | Universität Heidelberg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Restoring vision by gene therapy

Latest scientific findings give hope for people with incurable retinal degeneration

Humans rely dominantly on their eyesight. Losing vision means not being able to read, recognize faces or find objects. Macular degeneration is one of the major...

Im Focus: Small Protein, Big Impact

In meningococci, the RNA-binding protein ProQ plays a major role. Together with RNA molecules, it regulates processes that are important for pathogenic properties of the bacteria.

Meningococci are bacteria that can cause life-threatening meningitis and sepsis. These pathogens use a small protein with a large impact: The RNA-binding...

Im Focus: K-State study reveals asymmetry in spin directions of galaxies

Research also suggests the early universe could have been spinning

An analysis of more than 200,000 spiral galaxies has revealed unexpected links between spin directions of galaxies, and the structure formed by these links...

Im Focus: New measurement exacerbates old problem

Two prominent X-ray emission lines of highly charged iron have puzzled astrophysicists for decades: their measured and calculated brightness ratios always disagree. This hinders good determinations of plasma temperatures and densities. New, careful high-precision measurements, together with top-level calculations now exclude all hitherto proposed explanations for this discrepancy, and thus deepen the problem.

Hot astrophysical plasmas fill the intergalactic space, and brightly shine in stellar coronae, active galactic nuclei, and supernova remnants. They contain...

Im Focus: Biotechnology: Triggered by light, a novel way to switch on an enzyme

In living cells, enzymes drive biochemical metabolic processes enabling reactions to take place efficiently. It is this very ability which allows them to be used as catalysts in biotechnology, for example to create chemical products such as pharmaceutics. Researchers now identified an enzyme that, when illuminated with blue light, becomes catalytically active and initiates a reaction that was previously unknown in enzymatics. The study was published in "Nature Communications".

Enzymes: they are the central drivers for biochemical metabolic processes in every living cell, enabling reactions to take place efficiently. It is this very...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

Aachen Machine Tool Colloquium AWK'21 will take place on June 10 and 11, 2021

07.04.2020 | Event News

International Coral Reef Symposium in Bremen Postponed by a Year

06.04.2020 | Event News

 
Latest News

New image of a cancer-related enzyme in action helps explain gene regulation

05.06.2020 | Life Sciences

Silicon 'neurons' may add a new dimension to computer processors

05.06.2020 | Physics and Astronomy

Protecting the Neuronal Architecture

05.06.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>