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
Scientists enlist engineered protein to battle the MERS virus
22.05.2017 | University of Toronto
Insight into enzyme's 3-D structure could cut biofuel costs
19.05.2017 | DOE/Los Alamos National Laboratory
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.
In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...
Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...
For the first time, scientists have succeeded in studying the strength of hydrogen bonds in a single molecule using an atomic force microscope. Researchers from the University of Basel’s Swiss Nanoscience Institute network have reported the results in the journal Science Advances.
Hydrogen is the most common element in the universe and is an integral part of almost all organic compounds. Molecules and sections of macromolecules are...
22.05.2017 | Event News
17.05.2017 | Event News
16.05.2017 | Event News
22.05.2017 | Materials Sciences
22.05.2017 | Life Sciences
22.05.2017 | Physics and Astronomy