1,268 research outputs found
Editorial for This Special Issue "Synaptic Transmission: From Molecular to Neural Network Levels"
No full textWe invited contributions reporting new evidence of synaptic mechanisms and their network-level impacts for this Special Issue. The six research articles published in this collection, from 33 authors, cover many aspects of synaptic function and plasticity, from single-cell mechanisms to neuronal network properties. These papers elucidate the physiological and pathological conditions underlying synaptic transmission, giving new perspectives for future applications and therapies
Expression and localization of ryanodine receptors in the frog semicircular canal.
No full textSeveral experiments suggest an important role for store-released Ca2+ in hair cell organs: drugs targeting IP3 and ryanodine (RyRs) receptors affect release from hair cells, and stores are thought to be involved in vesicle recycling at ribbon synapses. In this work we investigated the semicircular canal distribution of RyRs by immunofluorescence, using slice preparations of the sensory epithelium (to distinguish cell types) and flat mounts of the simpler nonsensory regions. RyRs were present in hair cells, mostly in supranuclear spots, but not in supporting cells; as regards nonsensory regions, they were also localized in dark cells and cells from the ductus. No labeling was found in nerve terminals, although nerve branches could be observed in proximity to hair cell RyR spots. The differential expression of RyR isoforms was studied by RT-PCR and immunoblotting, showing the presence of RyRα in both ampulla and canal arm and RyRβ in the ampulla only
Ethene/4-methyl-1-pentene copolymers by metallocene based catalysts: an insight in 13C NMR assignment
No full textFirst person – Simona Amodeo
No full textABSTRACT
First Person is a series of interviews with the first authors of a selection of papers published in Journal of Cell Science, helping early-career researchers promote themselves alongside their papers. Simona Amodeo is the first author on ‘Characterization of the novel mitochondrial genome replication factor MiRF172 in Trypanosoma brucei’, published in Journal of Cell Science. Simona is a PhD student in the lab of Torsten Ochsenreiter at the Institute of Cell Biology, University of Bern, Switzerland, investigating mitochondrial genome anchoring, replication and inheritance in Trypanosoma brucei.</jats:p
Calyx and dimorphic neurons of mouse Scarpa's ganglion express histamine H3 receptors
No full textAbstract Background Histamine-related drugs are commonly used in the treatment of vertigo and related vestibular disorders. The site of action of these drugs however has not been elucidated yet. Recent works on amphibians showed that histamine H3 receptor antagonists, e.g. betahistine, inhibit the afferent discharge recorded from the vestibular nerve. To assess the expression of H3 histamine receptors in vestibular neurons, we performed mRNA RT-PCR and immunofluorescence experiments in mouse Scarpa's ganglia. Results RT-PCR analysis showed the presence of H3 receptor mRNA in mouse ganglia tissue. H3 protein expression was found in vestibular neurons characterized by large and roundish soma, which labeled for calretinin and calbindin. Conclusion The present results are consistent with calyx and dimorphic, but not bouton, afferent vestibular neurons expressing H3 receptors. This study provides a molecular substrate for the effects of histamine-related antivertigo drugs acting on (or binding to) H3 receptors, and suggest a potential target for the treatment of vestibular disorders of peripheral origin.</p
Guanidine transport across the apical and basolateral membranes of human intestinal Caco-2 cells is mediated by two different mechanisms
No full textThe functional characteristics of the intestinal absorption and secretion of guanidine as a model
of a nutritionally and metabolically essential organic cation were examined in the Caco-2 human intestinal cell
line. Both apical and basolateral transport of [14C]-guanidine were studied using Caco-2 cells grown on polycarbonate
permeable membranes. The basolateral-to-apical flux of [14C]-guanidine (i.e., its secretion) was quantitatively
higher than the apical-to-basolateral transport (i.e., its absorption). When Na was replaced by K or Li,
both apical and basolateral accumulation were significantly inhibited. Studies using the cell monolayers and apical
membrane vesicles obtained from Caco-2 cells showed a potential-independent mechanism of guanidine apical
uptake and efflux. Conversely, basolateral uptake and efflux were membrane potential dependent. Kinetic analysis
revealed that both saturable and nonsaturable mechanisms accounted for the apical and basolateral accumulations.
The [14C]-guanidine efflux from cells through the apical and basolateral membranes was significantly
reduced at 4°C, suggesting carrier-mediated mechanisms. Moreover, the apical efflux was stimulated by an
inwardly directed H gradient. Influx and efflux of [14C]-guanidine were unaffected by the presence of tetraethylammonium,
cimetidine or decynium-22 in the donor compartment. Only quinine significantly reduced [14C]-
guanidine entrance through apical and basolateral membranes and its exit through the basolateral membrane. In
conclusion, our results suggest that the influx and the efflux through the apical membrane is mediated by different
transporters, whereas transport across the basolateral membrane is mediated by a member of the organic cation
transporter family with high affinity for guanidine
Theta-patterned tactile stimulation modifies deep cerebellar nuclei neurons responsiveness in vivo
No full textSeveral forms of synaptic plasticity have been described in the cerebellar network in vitro, but how plasticity may be induced in vivo remains poorly explored. Sensory tactile stimuli organized in theta patterns have been reported to induce long-term changes in cerebellar granule cells (Roggeri et al., 2008), Purkinje cells and molecular layer interneurons (Ramakrishnan et al., 2016) in vivo. Deep cerebellar nuclei (DCN) neurons are known to respond to low frequency sensory stimulation through typical discharge patterns reflecting the inhibitory and excitatory inputs converging onto these nuclei, provided by Purkinje cells and mossy fibers respectively (Rowland and Jaeger, 2008). Nevertheless, whether and how DCN are able to modify their discharges following theta-patterned sensory stimulation remains unexplored. Herein, we addressed this issue performing single-unit recordings in vivo, from the medial nucleus of anesthetized mice. Our results provide the first evidence that DCN neurons are indeed able to modify their discharge properties following sensory stimulation in vivo, completing the picture of the theta sensory stimulation (TSS) impact on cerebellar neurons discharge in viv
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