The study will be published in the Journal of Neuroscience (February 28, 2007 issue). They had opportunity to determine activity-dependent plasticity – a cellular process, in which the connections between individual brain cells get stronger the more often they are used, such as during learning - in the hippocampus of freely moving mouse mutants. Recording in vivo techniques were developed last year by the group of Drs. J.M. Delgado-García and A. Gruart (see Gruart et al., 26: 1077-1087, 2006), and allow determining the explicit relation between the learning process and the physiological synaptic enhancement in the hippocampus.
Neurotrophins and their receptors might serve as feedback regulators for the efficacy of synaptic transmission. As recently shown in vivo by some of us, the BDNF-TrkB system is well known for its importance in synaptic plasticity and long-term potentiation (LTP) in the hippocampus (see Gruart et al., Learn. Mem., 4: 54-62, 2007). However, until now, the role of other neurotrophin systems in mediating synaptic modulation remained to be elucidated. In their study, the groups of Drs. M. Dierssen, and J.M. Delgado-García and A. Gruart used transgenic mice overexpressing TrkC to test the hypothesis that in vivo overexpression of the TrkC receptor could produce an increase in survival and/or neuronal induction or promotion in the hippocampus, with some putative consequences for learning and synaptic plasticity in adult mice. In their experiments, the activity-dependent strength of the hippocampal CA3-CA1 synapse –a brain region involved in learning- was recorded in behaving mice, while animals were being trained to the classical conditioning of eyelid responses.
For the first time, the work clearly provides evidence for a direct, causal role for the NT-3-TrkC cascade in the physiological potentiation of field excitatory post-synaptic potentials (fEPSP) evoked at the CA3-CA1 synapse during the acquisition of an associative learning task, as well as in early and late maintenance of experimentally induced LTP. Interestingly, overexpression of TrkC seems to reduce the efficiency of conditioned learning, an effect that has previously been observed after LTP ‘saturation’ induced experimentally in behaving mice (Gruart et al., 26: 1077-1087, 2006). It is thus possible that TrkC overexpression enhances too much hippocampal synaptic activity, which then occludes normal associative learning.
This paper shows for the first time the dissociation between the ability to learn a task and the changes in synaptic plasticity seen during synaptic potentiation in behaving mice and suggests that it is the combination of different neurotrophin systems what leads to the proper balance of learning abilities in mammals.
Gloria Lligadas | alfa
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17.10.2017 | King Abdullah University of Science & Technology (KAUST)
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
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