%0 Journal Article %D 2015 %T The phototransduction machinery in the rod outer segment has a strong efficacy gradient %A Monica Mazzolini %A Giuseppe Facchetti %A L. Andolfi %A R. Proietti Zaccaria %A S. Tuccio %A J. Treud %A Claudio Altafini %A Enzo M. Di Fabrizio %A Marco Lazzarino %A G. Rapp %A Vincent Torre %I National Academy of Sciences %G en %U http://urania.sissa.it/xmlui/handle/1963/35157 %1 35382 %2 Neuroscience %$ Approved for entry into archive by Lucio Lubiana (lubiana@sissa.it) on 2016-01-21T09:29:28Z (GMT) No. of bitstreams: 0 %R 10.1073/pnas.1423162112 %0 Journal Article %J Nature. Scientific Reports 3, Article number: 1251, Published : 13 February 2013 %D 2013 %T Common dynamical features of sensory adaptation in photoreceptors and olfactory sensory neurons. %A Giovanna De Palo %A Giuseppe Facchetti %A Monica Mazzolini %A Anna Menini %A Vincent Torre %A Claudio Altafini %X

Sensory systems adapt, i.e., they adjust their sensitivity to external stimuli according to the ambient level. In this paper we show that single cell electrophysiological responses of vertebrate olfactory receptors and of photoreceptors to different input protocols exhibit several common features related to adaptation, and that these features can be used to investigate the dynamical structure of the feedback regulation responsible for the adaptation. In particular, we point out that two different forms of adaptation can be observed, in response to steps and to pairs of pulses. These two forms of adaptation appear to be in a dynamical trade-off: the more adaptation to a step is close to perfect, the slower is the recovery in adaptation to pulse pairs and viceversa. Neither of the two forms is explained by the dynamical models currently used to describe adaptation, such as the integral feedback model.

%B Nature. Scientific Reports 3, Article number: 1251, Published : 13 February 2013 %I SISSA %G en %1 6453 %2 Mathematics %4 1 %$ Submitted by Claudio Altafini (altafini@sissa.it) on 2013-02-27T14:00:21Z\nNo. of bitstreams: 0 %R 10.1038/srep01251 %0 Journal Article %J PloS one. Volume 8, Issue 7, July 2013 : e68078 %D 2013 %T Early phase of plasticity-related gene regulation and SRF dependent transcription in the hippocampus %A Giovanni Iacono %A Claudio Altafini %A Vincent Torre %X Hippocampal organotypic cultures are a highly reliable in vitro model for studying neuroplasticity: in this paper, we analyze the early phase of the transcriptional response induced by a 20 µM gabazine treatment (GabT), a GABA-Ar antagonist, by using Affymetrix oligonucleotide microarray, RT-PCR based time-course and chromatin-immuno-precipitation. The transcriptome profiling revealed that the pool of genes up-regulated by GabT, besides being strongly related to the regulation of growth and synaptic transmission, is also endowed with neuro-protective and pro-survival properties. By using RT-PCR, we quantified a time-course of the transient expression for 33 of the highest up-regulated genes, with an average sampling rate of 10 minutes and covering the time interval [10:90] minutes. The cluster analysis of the time-course disclosed the existence of three different dynamical patterns, one of which proved, in a statistical analysis based on results from previous works, to be significantly related with SRF-dependent regulation (p-value<0.05). The chromatin immunoprecipitation (chip) assay confirmed the rich presence of working CArG boxes in the genes belonging to the latter dynamical pattern and therefore validated the statistical analysis. Furthermore, an in silico analysis of the promoters revealed the presence of additional conserved CArG boxes upstream of the genes Nr4a1 and Rgs2. The chip assay confirmed a significant SRF signal in the Nr4a1 CArG box but not in the Rgs2 CArG box. %B PloS one. Volume 8, Issue 7, July 2013 : e68078 %I Public Library of Science %G en %U http://hdl.handle.net/1963/7287 %1 7332 %2 Neuroscience %4 -1 %$ Submitted by Maria Pia Calandra (calapia@sissa.it) on 2014-03-14T11:26:18Z No. of bitstreams: 1 journal.pone.0068078.pdf: 1188661 bytes, checksum: 29e83864b33fd1a072fe4ab4da6fcc17 (MD5) %R 10.1371/journal.pone.0068078 %0 Journal Article %J BMC Research Notes (2009) 2:13 %D 2009 %T Characterization of the time course of changes of the evoked electrical activity in a model of a chemically-induced neuronal plasticity %A Frederic D. Broccard %A Silvia Pegoraro %A Maria Elisabetta Ruaro %A Claudio Altafini %A Vincent Torre %X BACKGROUND: Neuronal plasticity is initiated by transient elevations of neuronal networks activity leading to changes of synaptic properties and providing the basis for memory and learning 1. An increase of electrical activity can be caused by electrical stimulation 2 or by pharmacological manipulations: elevation of extracellular K+ 3, blockage of inhibitory pathways 4 or by an increase of second messengers intracellular concentrations 5. Neuronal plasticity is mediated by several biochemical pathways leading to the modulation of synaptic strength, density of ionic channels and morphological changes of neuronal arborisation 6. On a time scale of a few minutes, neuronal plasticity is mediated by local protein trafficking 7 while, in order to sustain modifications beyond 2-3 h, changes of gene expression are required 8. FINDINGS: In the present manuscript we analysed the time course of changes of the evoked electrical activity during neuronal plasticity and we correlated it with a transcriptional analysis of the underlying changes of gene expression. Our investigation shows that treatment for 30 min. with the GABAA receptor antagonist gabazine (GabT) causes a potentiation of the evoked electrical activity occurring 2-4 hours after GabT and the concomitant up-regulation of 342 genes. Inhibition of the ERK1/2 pathway reduced but did not abolish the potentiation of the evoked response caused by GabT. In fact not all the genes analysed were blocked by ERK1/2 inhibitors. CONCLUSION: These results are in agreement with the notion that neuronal plasticity is mediated by several distinct pathways working in unison. %B BMC Research Notes (2009) 2:13 %I BioMed Central %G en_US %U http://hdl.handle.net/1963/3706 %1 599 %2 Neuroscience %3 Neurobiology %$ Submitted by Andrea Wehrenfennig (andreaw@sissa.it) on 2009-08-12T11:40:38Z\\nNo. of bitstreams: 1\\n1756-0500-2-13.pdf: 518127 bytes, checksum: 0cd264c3567a0d1776a5141b6dc5ef4e (MD5) %R 10.1186/1756-0500-2-13