1,721,001 research outputs found
Phosphorylation of S845 GluA1 AMPA receptors modulates spatial memory and structural plasticity in the ventral striatum.
No full textThe function of AMPA receptors phosphorylation in synaptic plasticity has been dissected in many in vitro models but its role and dynamics on experience-dependent plasticity are still unclear. Here we studied the effects of AMPA receptor manipulations in the ventral striatum, where glutamatergic transmission is known to mediate spatial memory. We first demonstrate that intra-ventral striatal administrations of the AMPA receptors blocker, NBQX, dose dependently impair performance in the Morris water maze. We also report that spatial learning induced a time-limited increase in GluA1 phosphorylation in this same brain region. Finally, through focal, time-controlled ventral striatal administrations of an RNA aptamer interfering with GluA1-S845 phosphorylation, we demonstrate that phosphorylation at this site is a necessary requirement for spatial memory formation and for the synaptic remodeling underlying it. These results suggest that modulation of AMPA receptors by S845 phosphorylation could act as an essential starting signal leading to long-term stabilization of spatial memories
Strains of Rodents and the Pharmacology of Learning and Memory
No full textMendelian genetic tools have extensively been used to improve the description of the pharmacological mechanisms involved in learning and memory. The first part of this short review describes experiments involving the bidirectional selection of rats or mice for extreme behavioral characteristics or for sensitivity to pharmacological treatments. The second part focuses specifically on in-breeding. In conclusion, the advantages and the limits of a Mendelian pharmacogenetic approach of learning and memory are discussed
Strains of Rodents and the Pharmacology of Learning and Memory
Full text linkMendelian genetic tools have extensively
been used to improve the description of the
pharmacological mechanisms involved in
learning and memory. The first part of this
short review describes experiments involving
the bidirectional selection of rats or mice for
extreme behavioral characteristics or for
sensitivity to pharmacological treatments.
The second part focuses specifically on inbreeding.
In conclusion, the advantages and
the limits of a Mendelian pharmacogenetic
approach of learning and memory are
discussed
Enhanced mGlu5-receptor dependent long-term depression at the Schaffer collateral-CA1 synapse of congenitally learned helpless rats
No full textAlterations of the glutamatergic system have been implicated in the pathophysiology and treatment of major depression. In order to investigate the expression and function of mGlu5 receptors in an animal model for treatment-resistant depression we used rats bred for congenital learned helplessness (cLH) and the control strain, bred for resistance against inescapable stress, congenitally. not learned helpless rats (cNLH). Western blot analysis showed an increased expression of mGlu5 (but not mGlu1a) receptors in the hippocampus of cLH rats, as compared with control cNLH rats. We also examined mGlu1/5 receptor signaling by in vivo measurement of DHPG-stimulated polyphosphoinositides hydrolysis. Stimulation of (3)H-inositolmonophosphate formation induced by i.c.v. injection of DHPG was enhanced by about 50% in the hippocampus of cLH rats. Correspondingly, DHPG-induced long-term depression (LTD) at Schaffer collateral/CA1 pyramidal cell synapses was amplified in hippocampal slices of cLH rats, whereas LTD induced by low frequency stimulation of the Schaffer collaterals did not change. Moreover, these effects were associated with decreased basal dendritic spine density of CA1 pyramidal cell in cLH rats. These data raise the attractive possibility that changes in the expression and function of mGlu5 receptors in the hippocampus might underlie the changes in synaptic plasticity associated with the depressive-like phenotype of cLH rats. However, chronic treatment of cLH rats with MPEP did not reverse learned helplessness, indicating that the enhanced mGlu5 receptor function is not the only player in the behavioral phenotype of this genetic model of depression. This article is part of a Special Issue entitled 'Metabotropic Glutamate Receptors'. Copyright © 2012 Elsevier Ltd. All rights reserved
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
The strain-specific involvement of nucleus accumbens in latent inhibition might depend on differences in processing configural- and cue-based information between C57BL/6 and DBA mice
No full text- …
