Fine structure of the retinal photoreceptors of the tiger salamander (Ambystoma tigrinum)

Braekevelt, C. R.

Publication:
Fine structure of the retinal photoreceptors of the tiger salamander (Ambystoma tigrinum)

dc.contributor.author	Braekevelt, C. R.
dc.date.accessioned	2020-07-03T10:34:56Z
dc.date.available	2020-07-03T10:34:56Z
dc.date.issued	1993
dc.description.abstract	The retinal photoreceptors of the tiger salamander (Ambystoma tigrinum) have been studied by light and electron microscopy in both light- and dark-adaptation. Rods and cones are present in this duplex retina in a ratio of about 20:1. As in other urodele species these photoreceptors are very large cells. The rod outer segment is composed of bi-membranous discs of uniform diameter displaying several very deep incisures. The rod inner segment displays an ellipsoid of mitochondria and a myoid region which changes in diameter during the lighting cycle indicating that rods undergo photomechanical movements. Rod nuclei are located at all levels of the outer nuclear layer and rod spherules are large and display several invaginated and superficial synaptic sites. Cone photoreceptors while large cells are smaller than the rods. They show a smaller tapering outer segment, a large distal ellipsoid of mitochondria and a prominent paraboloid of glycogen but no oil droplet within the inner segment. Judging by the width of the myoid region which remains similar throughout the lighting cycle, cones in this species show no retino-motor responses. Cone nuclei are less electron dense than rods and are also located at all levels of the outer nuclear layer. The cone synaptic pedicle is larger than that of the rods and also shows several invaginated and superficial synaptic sites.	es
dc.format	application/pdf	es
dc.format.extent	8	es
dc.identifier.citation	Histology and Histopathology, Vol. 8, n.º 2 (1993)
dc.identifier.issn	1699-5848
dc.identifier.issn	0213-3911
dc.identifier.uri	http://hdl.handle.net/10201/94402
dc.language	eng	es
dc.publisher	F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología	es
dc.rights	info:eu-repo/semantics/openAccess	es
dc.rights	Attribution-NonCommercial-NoDerivatives 4.0 International	*
dc.rights.uri	http://creativecommons.org/licenses/by-nc-nd/4.0/	*
dc.subject	Photoreceptors	es
dc.subject	Electron microscopy	es
dc.subject	Amphibian	es
dc.subject	Tiger salamander	es
dc.subject	Anbystoma tigrinum	es
dc.subject.other	CDU::5 - Ciencias puras y naturales::57 - Biología::576 - Biología celular y subcelular. Citología	es
dc.title	Fine structure of the retinal photoreceptors of the tiger salamander (Ambystoma tigrinum)	es
dc.type	info:eu-repo/semantics/article	es
dspace.entity.type	Publication	es