{"id":333,"date":"2012-06-07T15:49:11","date_gmt":"2012-06-07T13:49:11","guid":{"rendered":"http:\/\/project.inria.fr\/keops\/?page_id=333"},"modified":"2012-07-24T17:17:12","modified_gmt":"2012-07-24T15:17:12","slug":"recherche-observer","status":"publish","type":"page","link":"https:\/\/project.inria.fr\/keops\/recherche-2\/recherche-observer\/","title":{"rendered":"Research : Observing"},"content":{"rendered":"<p><strong><span style=\"color: #ff0000; font-size: large;\">Dynamics of non-standard retinal-sensor behavior for natural images processing.<\/span><\/strong><\/p>\n<p><strong>Objective:<\/strong> Collect existing and new experimental facts on non-standard behaviors of retinal\u00a0ganglions cells in order to understand the computational capabilities of the retina under natural\u00a0dynamic simulations.<\/p>\n<p><strong>Methods:<\/strong> Multielectrodes arrays (MEA) system (64 X PLEXON amplifier, National Instrument\u00a0(NI625X) acquisition board (10-25 KHz) and hard drives for the storage) for field potential or spike\u00a0recording is operational in our lab. MEA arrays are commercially available (Multichannel System).<br \/>\nThe retina is mounted in a perfusion camera with AMES or equivalent solution, oxygenates and\u00a0maintained at 35oC, under controlled light conditions. Labview homemade software (SpikeHunter)\u00a0for signal acquisition, control and exportation and visualization (SpikePlay) is use. OFF line\u00a0visualization, analysis, spike clustering and cross-correlograms response are done with MATLAB\u00a0routines and following (Schwartz and Berry, 2008; Schwartz et al., 2007) protocols. An advantage\u00a0of recording from as many 50-100 using MEA arrays, neurons is the simultaneously access to\u00a0\u201cpopulation coding\u201d from a complete retina ganglion cell assembly. The physiological characteristics\u00a0of ganglion cells with respect to natural images stimulus, including (e.g.) contrast-intensity, color, texture, will be uses to characterize properties of firings (transients, sustain) ON \/ OFF, size and organization of receptive fields. The Universidad\u00a0de Valparaiso is an institution with an approved animal welfare assurance (A5823-01) from the NIH\u00a0(USA).<\/p>\n<p><a href=\"http:\/\/project.inria.fr\/keops\/files\/2012\/03\/Keopst1-1.jpg\"><img loading=\"lazy\" decoding=\"async\" title=\"Keopst1-1\" src=\"http:\/\/project.inria.fr\/keops\/files\/2012\/03\/Keopst1-1.jpg\" alt=\"\" width=\"1165\" height=\"748\" \/><\/a><br \/>\nFigure joint shows our protocol and data samples. Inset A) Labview home made software for MEA\u00a0data recording. We see some spike activity in some of the channels; B) MEA matrix 64 X\u00a0electrodes; C) SpikeIt homemade software e.g. two acquisition channels and in the bottom the\u00a0sequence of light flashes. One channel shows spikes; D) a plot raw data with more channels and\u00a0spikes (dark vertical activity); E) As example, two templates for spike sorting base on data in D) and F) e.g.\u00a0raster of response for 3 different ganglion cells (the plot alignment is displace compare to D).<\/p>\n<p><strong>Task steps:<\/strong><br \/>\n(i) Review of available experimental data on retinal responses to dynamic and natural stimuli, the\u00a0proposed models and the emerging computational properties (this preliminary task is\u00a0important in this multidisciplinary context).<br \/>\n(ii) Design of the new stimulation protocols and validation of the natural image sequence\u00a0stimulator.<br \/>\n(iii) Physiological experiments recording the retinal activity, using Patch clamp and Multielectrodes,\u00a0methods, in rodents and amphibians, in response to natural (e.g. movies) visual stimulus.<br \/>\n(iv) Data basing and preprocessing of the ganglion cells recordings.<\/p>","protected":false},"excerpt":{"rendered":"<p>Dynamics of non-standard retinal-sensor behavior for natural images processing. Objective: Collect existing and new experimental facts on non-standard behaviors of retinal\u00a0ganglions cells in order to understand the computational capabilities of the retina under natural\u00a0dynamic simulations. Methods: Multielectrodes arrays (MEA) system (64 X PLEXON amplifier, National Instrument\u00a0(NI625X) acquisition board (10-25 KHz) and hard drives for the &hellip; <\/p>\n<p><a class=\"more-link btn\" href=\"https:\/\/project.inria.fr\/keops\/recherche-2\/recherche-observer\/\">Continue reading<\/a><\/p>\n","protected":false},"author":36,"featured_media":0,"parent":128,"menu_order":1,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-333","page","type-page","status-publish","hentry","nodate","item-wrap"],"_links":{"self":[{"href":"https:\/\/project.inria.fr\/keops\/wp-json\/wp\/v2\/pages\/333","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/project.inria.fr\/keops\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/project.inria.fr\/keops\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/project.inria.fr\/keops\/wp-json\/wp\/v2\/users\/36"}],"replies":[{"embeddable":true,"href":"https:\/\/project.inria.fr\/keops\/wp-json\/wp\/v2\/comments?post=333"}],"version-history":[{"count":10,"href":"https:\/\/project.inria.fr\/keops\/wp-json\/wp\/v2\/pages\/333\/revisions"}],"predecessor-version":[{"id":648,"href":"https:\/\/project.inria.fr\/keops\/wp-json\/wp\/v2\/pages\/333\/revisions\/648"}],"up":[{"embeddable":true,"href":"https:\/\/project.inria.fr\/keops\/wp-json\/wp\/v2\/pages\/128"}],"wp:attachment":[{"href":"https:\/\/project.inria.fr\/keops\/wp-json\/wp\/v2\/media?parent=333"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}