Browsing by Subject "Intrinsically photosensitive RGC"

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    Retino-retinal projection in juvenile and young adult rats and mice
    (Elsevier, 2015-05-01) Nadal-Nicolás, Francisco Manuel; Valiente Soriano, Francisco Javier; Salinas Navarro, Manuel Ángel; Jiménez López, Manuel; Vidal Sanz, Manuel; Agudo Barriuso, Marta; Oftalmología, Optometría, Otorrinolaringología y Anatomía Patológica; Facultades de la UMU::Facultad de Medicina
    Identification of retino-retinal projecting RGCs (ret-ret RGCs) has been accomplished by tracing RGCs in one retina after intravitreal injection of different tracers in the other eye. In mammals, rabbit and rat, ret-ret RGCs are scarce and more abundant in newborn than in adult animals. To our knowledge, ret-ret RGCs have not been studied in mice. Here we purpose to revisit the presence of ret-ret RGCs in juvenile and young adult rats and mice by using retrograde tracers applied to the contralateral optic nerve instead of intravitreally. In P20 (juvenile) and P60 (young adult) animals, the left optic nerve was intraorbitally transected and Fluorogold (rats) or its analogue OHSt (mice) were applied onto its distal stump. P20 animals were sacrificed 3 (mice) or 5 (rats) days later and adult animals at 5 (mice) or 7 (rats) days. Right retinas were dissected as flat-mounts and double immunodetected for Brn3a and melanopsin. Ret-ret RGCs were those with tracer accumulation in their somas. Out of them some expressed Brn3a and/or melanopsin, while other were negative for both markers. In young adult rats, we found 2 ret-ret RGCs displaced to the inner nuclear layer. In both species, ret-ret RGCs are quite scarce and found predominantly in the nasal retina. In juvenile animals there are significantly more ret-ret RGCs (9 ± 3, rats, 13 ± 3 mice) than in young adult ones (5 ± 6 rats, 7 ± 3 mice). Finally, juvenile and young adult mice have more ret-ret RGCs than rats.
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    Survival of melanopsin expressing retinal ganglion cells long term after optic nerve trauma in mice
    (Elsevier, 2018-05-29) Sánchez-Migallón, María Cielo ; Valiente Soriano, Francisco Javier; Nadal-Nicolás, Francisco Manuel; Di Pierdomenico, Johnny; Vidal Sanz, Manuel; Agudo Barriuso, Marta; Oftalmología, Optometría, Otorrinolaringología y Anatomía Patológica; Facultad de Medicina
    In this study we have compared the response to optic nerve crush (ONC) and to optic nerve transection (ONT) of the general population of retinal ganglion cells in charge of the image-forming visual functions that express Brn3a (Brn3a+RGCs) with that of the sub-population of non-image forming RGCs that express melanopsin (m+RGCs). Intact animals were used as control. ONT and ONC were performed at 0.5 mm from the optic disk, and retinas dissected 3, 5, 7, 14, 30, 45 or 90 days later (n = 5/injury/time point). In all the retinas, Brn3a+RGCs and m+RGCs were identified and their survival analyzed quantitatively and topographically. There were no differences in the course of RGC loss between lesions. The decrease of RGCs was significant at short time points (3 or 5 days for Brn3a+ or m+ RGCs, respectively) and, up to 14 days, the course of loss of both RGC populations was similar, surviving at this time point between 20 and 22% of their original population. However, while the loss of Brn3a+RGCs continues steadily up to 90 days when only 5–6% of them still remain, the loss of m+RGCs stops at 14 days, and the proportion of surviving m+RGCs remains constant up to 90 days (26–30%). In conclusion, m+RGC do not respond to axotomy in the same way than the rest of RGCs, and so whilst imageforming RGCs die in two exponential phases a quick one and a slow protracted one, non-image forming RGCs die only during the first quick phase.