title: Number and spatial distribution of intrinsically photosensitive retinal ganglion cells in the adult albino rat.
abstract: Intrinsically photosensitive retinal ganglion cells (ipRGCs) respond directly to light and are responsible of the synchronization of the circadian rhythm with the photic stimulus and for the pupillary light reflex. To quantify the total population of rat-ipRGCs and to assess their spatial distribution we have developed an automated routine and used neighbour maps. Moreover, in all analysed retinas we have studied the general population of RGCs - identified by their Brn3a expression - and the population of ipRGCs - identified by melanopsin immunodetection - thus allowing the co-analysis of their topography. Our results show that the total mean number ± standard deviation of ipRGCs in the albino rat is 2047 ± 309. Their distribution in the retina seems to be complementary to that of Brn3a(+)RGCs, being denser in the periphery, especially in the superior retina where their highest densities are found in the temporal quadrant, above the visual streak. In addition, by tracing the retinas from both superior colliculi, we have also determined that 90.62% of the ipRGC project to these central targets.
authors.affiliation: Departamento de Oftalmología, Facultad de Medicina, Regional Campus of International Excellence Campus Mare Nostrum, Instituto Murciano de Investigaciones Biosanitarias, Campus de Espinardo Universidad de Murcia, E-30100 Espinardo, Murcia, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Galindo-Romero
authors.forename: M
authors.initials: M
authors.lastname: Jiménez-López
authors.forename: D
authors.initials: D
authors.lastname: García-Ayuso
authors.forename: M
authors.initials: M
authors.lastname: Salinas-Navarro
authors.forename: F M
authors.initials: FM
authors.lastname: Nadal-Nicolás
authors.forename: M
authors.initials: M
authors.lastname: Agudo-Barriuso
authors.forename: M P
authors.initials: MP
authors.lastname: Villegas-Pérez
authors.forename: M
authors.initials: M
authors.lastname: Avilés-Trigueros
authors.forename: M
authors.initials: M
authors.lastname: Vidal-Sanz
mesh_terms: D000417:Albinism / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002452:Cell Count; D004195:Disease Models, Animal; D005260:Female; D008027:Light; D009434:Neural Pathways / Q000473:pathology; D056347:Neuroanatomical Tract-Tracing Techniques; D010775:Photic Stimulation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012165:Retinal Ganglion Cells / Q000378:metabolism / Q000473:pathology* / Q000528:radiation effects; D017299:Rod Opsins / Q000378:metabolism; D013477:Superior Colliculi / Q000473:pathology; D050819:Transcription Factor Brn-3A / Q000378:metabolism; D014785:Vision, Ocular; D000099210:Melanopsin
chemical_list: D015415:Biomarkers; D017299:Rod Opsins; D050819:Transcription Factor Brn-3A; D000099210:Melanopsin