Catholic University of the Sacred Heart

About: Catholic University of the Sacred Heart is a education organization based out in Milan, Lombardia, Italy. It is known for research contribution in the topics: Population & Health care. The organization has 13592 authors who have published 31048 publications receiving 853961 citations.

M Channels Containing KCNQ2 Subunits Modulate Norepinephrine, Aspartate, and GABA Release from Hippocampal Nerve Terminals

Abstract: KCNQ subunits encode for the M current ( I KM), a neuron-specific voltage-dependent K+ current with a well established role in the control of neuronal excitability. In this study, by means of a combined biochemical, pharmacological, and electrophysiological approach, the role of presynaptic I KM in the release of previously taken up tritiated norepineprine (NE), GABA, and d-aspartate (d-ASP) from hippocampal nerve terminals (synaptosomes) has been evaluated. Retigabine (RT) (0.01-30 μm), a specific activator of I KM, inhibited [3H]NE, [3H]d-ASP, and [3H]GABA release evoked by 9 mm extracellular K+ ([K+]e). RT-induced inhibition of [3H]NE release was prevented by synaptosomal entrapment of polyclonal antibodies directed against KCNQ2 subunits, an effect that was abolished by antibody preabsorption with the KCNQ2 immunizing peptide; antibodies against KCNQ3 subunits were ineffective. Flupirtine (FP), a structural analog of RT, also inhibited 9 mm [K+]e-induced [3H]NE release, although its maximal inhibition was lower than that of RT. Electrophysiological studies in KCNQ2-transfected Chinese hamster ovary cells revealed that RT and FP (10 μm) caused a -19 and -9 mV hyperpolarizing shift, respectively, in the voltage dependence of activation of KCNQ2 K+ channels. In the same cells, the cognition enhancer 10,10-bis(4-pyridinylmethyl)-9(10H)-anthracenone (XE-991) (10 μm) blocked KCNQ2 channels and prevented their activation by RT (1-10 μm). Finally, both XE-991 (10-100 μm) and tetraethylammonium ions (100 μm) abolished the inhibitory effect of RT (1 μm) on [3H]NE release. These findings provide novel evidence for a major regulatory role of KCNQ2 K+ channel subunits in neurotransmitter release from rat hippocampal nerve endings.

Postnatal Development of Intestinal Microflora as Influenced by Infant Nutrition

Abstract: The postnatal period of a new human being is characterized, from the microbiological point of view, by the formation of a new ecosystem: the microflora of the human gut. In adulthood a number of barriers exert a potent selective action on bacteria arriving from the mouth, but in the very first stage of our life, these barriers are kept at a very low level, temporarily allowing penetration into the gut of bacteria that are not really believed to be "gut related." Moreover, type of delivery (natural vs. cesarean) and feeding (breast vs. bottle feeding) play dramatic roles in determining the microflora composition. In the last decade a number of articles have reported results on neonates' microflora obtained by means of culture-independent analysis. Data obtained by means of these techniques are in agreement with those produced by selective media, but they also provide some new insights about the presence of anaerobic bacteria. The focus of this article is to update knowledge on infants' microflora during the first 6 mo of life.