Nature Neuroscience Reviews NATURE REVIEWS REVIEWS NATURE and obtainedlevelsofphotoreceptor and theinferiorretina of the donorcellsintobothsuperior that involvedsubretinal injectionof optimized transplantation procedures protein (NRL)).Theauthorsused neural retina-specific leucinezipper the rod-specific transcription factor rod photoreceptors (undercontrol of fluorescent protein asamarkerof identified thecellsusinggreen from neonatalmouseretinae, having precursor cellsfortransplantation these cells.Theythenharvestedrod essential forphototransduction in of had beenablatedthrough knockout which rod-photoreceptor function of stationarynightblindnessin rod-photoreceptor transplantation. mouse modelofblindnessfollowing demonstrates restored vision in a genetic uncertain. AstudybyPearson a functionalimprovement invisionis integrate intoretinal circuits toproduce phenotype, whetherthesecells and acquire amature photoreceptor photoreceptor cellscandifferentiate it hasbeenshownthattransplanted by retinal degeneration. Although treatment strategy forblindnesscaused Cell transplantation isapossible see thelight Transplanted photoreceptors The authors used a murine model The authorsusedamurinemodel α NEURODEGENERATIVE DISORDERS -transducin (GNAT1), aprotein |

NEUROSCIENCE Gnat1 et al. –/–

| AOP, published online 10May 2011;doi:10.1038/nrn3265

mice mice now now

flickering blackandwhitebarsonagrey stimulation ofeacheyeusingdim transmitted tovisualcortex.Indeed, then signalsfrom thesecellswouldbe properly integrated intoretinal circuits, They reasoned thatiftherods had light inasimilarwaytowild-typerods. found thatthesecellsresponded to of individualintegrated rods. They rods usingsuction-pipetterecordings responses ofintegrated transplanted formed asimilararrangement. transplanted rod photoreceptors tohave ultrastructural analysisconfirmed bipolar andhorizontalcells, triad synapsewithretinal second-order dystrophin. Wild-typerods formaclassic proteins suchasribeye,bassoonand boutons expressing rod ribbonsynapse layer oftheretina, andmosthadsynaptic cells were locatedintheouternuclear Like wild-typerods, thetransplanted similar towild-typerod photoreceptors. rod markersandwere morphologically showed thattheyexpressed mature characterization oftheintegrated cells studies. than theirprevious transplantation integration thatwere 20–30-foldhigher in visual cortex of wild-type mice in visualcortexofwild-typemice background evokedstrong responses Next, the authors tested the light Next, theauthorstestedlight Morphological andfunctional © 2012 Macmillan Publishers Limited. Allrights reserved

to assesscognitiveprocessing ofvisual visually guidedwater-maze test—used photoreceptors did.Furthermore, ina that hadreceived transplanted rod head-tracking behaviour, whereas mice grating. their headsinthedirection ofarotating transplanted micereflexively moved this, theauthorsmonitored whetherthe improved bytransplantation. To test however, waswhethervisionhadbeen Gnat1 rod transplants, butnotinuntreated and transplantation canrestore vision. findings showthatinmice,atleast,retinal rod photoreceptors. Overall, these correlated withthenumberofintegrated both behavioural tests,performancewas untreated were abletosolvethetask,whereas Gnat1 information —onlywild-typemiceand nature10997) photoreceptors. Restoration ofvisionafter transplantation of O BRAND X The mostimportantquestion, RIGINAL RESEARCHPAPER RESEARCH HIGHLIGHTS Gnat1 –/– –/– micereceiving rod transplants mice. mice. Gnat1 Gnat1 –/–

mice thathadreceived Nature –/– mice exhibited no miceexhibitedno –/–

mice could not. In mice couldnot.In 18Apr2012(doi:10.1038/ Pearson, R.A. Sian Lewis et al .

VOLUME 13

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JUNE 2012