PURPOSE: To study the population of intrinsically photosensitive retinal ganglion cells (melanopsin-expressing RGCs, m+RGCs) in P23H-1 rats, a rat model of inherited photoreceptor degeneration. METHODS: At postnatal (P) times P30, P365, and P540, retinas from P23H dystrophic rats (line 1, rapid degeneration; and line 3, slow degeneration) and Sprague Dawley (SD) rats (control) were dissected as whole-mounts and immunodetected for melanopsin and/or Brn3a. The dendritic arborization of m+RGCs and the numbers of Brn3a+RGCs and m+RGCs were quantified and their retinal distribution and coexpression analyzed. RESULTS: In SD rats, aging did not affect the population of Brn3a+RGCs or m+RGCs or the percentage that showed coexpression (0.27%). Young P23H-1 rats had a significantly lower number of Brn3a+RGCs and showed a further decline with age. The population of m+RGCs in young P23H-1 rats was similar to that found in SD rats and decreased by 22.6% and 28.2% at P365 and P540, respectively, similarly to the decrease of the Brn3a+RGCs. At these ages the m+RGCs showed a decrease of their dendritic arborization parameters, which was similar in both the P23H-1 and P23H-3 lines. The percentage of coexpression of Brn3a was, however, already significantly higher at P30 (3.31%) and increased significantly with age (10.65% at P540). CONCLUSIONS: Inherited photoreceptor degeneration was followed by secondary loss of Brn3a+RGCs and m+RGCs. Surviving m+RGCs showed decreased dendritic arborization parameters and increased coexpression of Brn3a and melanopsin, phenotypic and molecular changes that may represent an effort to resist degeneration and/or preferential survival of m+RGCs capable of synthesizing Brn3a.
PURPOSE: To study the population of intrinsically photosensitive retinal ganglion cells (melanopsin-expressing RGCs, m+RGCs) in P23H-1 rats, a rat model of inherited photoreceptor degeneration. METHODS: At postnatal (P) times P30, P365, and P540, retinas from P23Hdystrophicrats (line 1, rapid degeneration; and line 3, slow degeneration) and Sprague Dawley (SD) rats (control) were dissected as whole-mounts and immunodetected for melanopsin and/or Brn3a. The dendritic arborization of m+RGCs and the numbers of Brn3a+RGCs and m+RGCs were quantified and their retinal distribution and coexpression analyzed. RESULTS: In SD rats, aging did not affect the population of Brn3a+RGCs or m+RGCs or the percentage that showed coexpression (0.27%). Young P23H-1 rats had a significantly lower number of Brn3a+RGCs and showed a further decline with age. The population of m+RGCs in young P23H-1 rats was similar to that found in SD rats and decreased by 22.6% and 28.2% at P365 and P540, respectively, similarly to the decrease of the Brn3a+RGCs. At these ages the m+RGCs showed a decrease of their dendritic arborization parameters, which was similar in both the P23H-1 and P23H-3 lines. The percentage of coexpression of Brn3a was, however, already significantly higher at P30 (3.31%) and increased significantly with age (10.65% at P540). CONCLUSIONS:Inherited photoreceptor degeneration was followed by secondary loss of Brn3a+RGCs and m+RGCs. Surviving m+RGCs showed decreased dendritic arborization parameters and increased coexpression of Brn3a and melanopsin, phenotypic and molecular changes that may represent an effort to resist degeneration and/or preferential survival of m+RGCs capable of synthesizing Brn3a.
Authors: Adam M Hanif; Moon K Kim; Joel G Thomas; Vincent T Ciavatta; Micah Chrenek; John R Hetling; Machelle T Pardue Journal: Exp Eye Res Date: 2016-06-18 Impact factor: 3.467
Authors: Matthew M LaVail; Shimpei Nishikawa; Roy H Steinberg; Muna I Naash; Jacque L Duncan; Nikolaus Trautmann; Michael T Matthes; Douglas Yasumura; Cathy Lau-Villacorta; Jeannie Chen; Ward M Peterson; Haidong Yang; John G Flannery Journal: Exp Eye Res Date: 2017-11-06 Impact factor: 3.467
Authors: Pablo F Barcelona; Nicholas Sitaras; Alba Galan; Gema Esquiva; Sean Jmaeff; Yifan Jian; Marinko V Sarunic; Nicolas Cuenca; Przemyslaw Sapieha; H Uri Saragovi Journal: J Neurosci Date: 2016-08-24 Impact factor: 6.167
Authors: Laura Fernández-Sánchez; Irene Bravo-Osuna; Pedro Lax; Alicia Arranz-Romera; Victoria Maneu; Sergio Esteban-Pérez; Isabel Pinilla; María Del Mar Puebla-González; Rocío Herrero-Vanrell; Nicolás Cuenca Journal: PLoS One Date: 2017-05-25 Impact factor: 3.240
Authors: Gema Esquiva; Pedro Lax; Juan J Pérez-Santonja; José M García-Fernández; Nicolás Cuenca Journal: Front Aging Neurosci Date: 2017-04-04 Impact factor: 5.750