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.
Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz
Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences