Collège de France

About: Collège de France is a education organization based out in Paris, France. It is known for research contribution in the topics: Population & Receptor. The organization has 6541 authors who have published 11983 publications receiving 648742 citations. The organization is also known as: College de France.

In Vivo Release of Endogenous Amino Acids from the Rat Striatum: Further Evidence for a Role of Glutamate and Aspartate in Corticostriatal Neurotransmission

Abstract: By means of the push-pull cannula method, the outflow of endogenous amino acids was studied in the striatum of halothane-anesthetized rats. Addition of K + ions (30 mM for 4 min) to the superfusion fluid increased the release of aspartate (+116%), glutamate (+ 217%), taurine (+109%), and γ-aminobutyric acid (GABA) (−429%) whereas a prolonged decrease in the outflow of glutamine (−28%) and a delayed reduction in the efflux of tyrosine (−25%) were observed. In the absence of Ca2-, the K+-induced release of aspartate, glutamate, and GABA was blocked whereas the K + -induced release of taurine was still present. Under these conditions, the decrease in glutamine efflux was reduced and that of tyrosine was abolished. Local application of tetrodotoxin (5 μM) decreased only the outflow of glutamate (-25%). One week following lesion of the ipsilateral sensorimotor cortex the spontaneous outflow of glutamine and of tyrosine was enhanced. Despite the lack of change in their spontaneous outflow, the K +-evoked release of aspartate and glutamate was less pronounced in lesioned than in control animals, whereas the K + -evoked changes in GABA and glutamine efflux were not modified. Our data indicate that the push-pull cannula method is a reliable approach for the study of the in vivo release of endogenous amino acids. In addition, they provide further evidence for a role for glutamate and aspartate as neuro-transmitters of corticostriatal neurons.

Study of structure and electrical conductivity in microemulsions : Evidence for percolation mechanism and phase inversion

Abstract: We present a study of structure and electrical conductivity in concentrated microemulsions. In the concentration range where the structure of the droplet is unchanged, the giant changes of the conductivity over 5 decades are interpreted in terms of a percolation model. Above the random packing fraction density the structure is inverted (w/o ~ o/w). The mechanism of conductivity is modified. LE JOURNAL DE PHYSIQUE LETTRES TOME 39, 15 DÉCEMBRE 1978,

50 years of allosteric interactions: the twists and turns of the models

Abstract: The concept of allosteric interactions between topographically distinct sites, and the subsequent Monod-Wyman-Changeux model proposed in 1965 for the conformational change mediating them, arose around 50 years ago. Many classic regulatory proteins follow this model, which has been expanded and challenged over the years.