June 2021
Volume 62, Issue 8
Open Access
ARVO Annual Meeting Abstract  |   June 2021
Ultrastructural features of rod synaptic terminals in the simplex retina of skate
Author Affiliations & Notes
  • Abhi S Wagh
    Biology, San Francisco State University, San Francisco, California, United States
  • Jessamyn G Fathi
    Biology, San Francisco State University, San Francisco, California, United States
  • Altan-Od Baatar
    Biology, San Francisco State University, San Francisco, California, United States
  • Ivan A Anastassov
    Biology, San Francisco State University, San Francisco, California, United States
  • Footnotes
    Commercial Relationships   Abhi Wagh, None; Jessamyn Fathi, None; Altan-Od Baatar, None; Ivan Anastassov, None
  • Footnotes
    Support  Genentech Foundation, NIH MBRS-RISE: R25-GM059298
Investigative Ophthalmology & Visual Science June 2021, Vol.62, 3042. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Abhi S Wagh, Jessamyn G Fathi, Altan-Od Baatar, Ivan A Anastassov; Ultrastructural features of rod synaptic terminals in the simplex retina of skate. Invest. Ophthalmol. Vis. Sci. 2021;62(8):3042.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose : In duplex retinae, the processing of visual information under scotopic and photopic light conditions is separated between the rod and cone photoreceptor systems. However, the elasmobranch little skate (L. erinacea) has a simplex retina, which contains only rods. This pure-rod retina can perform under scotopic and photopic light conditions with one complement of photoreceptors. We have little knowledge about the anatomical basis of this functional plasticity in skate rods.

Methods : Eyes from little skate were hemisected and choroid-attached pieces of retina from the tapetal area were obtained. Retinal pieces were embedded in resin blocks and SB-3DEM was performed. The dataset analyzed here was from a region of interest in the OPL of the skate retina with width/height = 34.4μm, section thickness = 0.075μm, and depth = 15μm. Voxel size was 4.5nmX4.5nmX75nm. 3D reconstructions and measurements of rod terminal features were done with Reconstruct and Amira software.

Results : The outer segments of skate rods display typical “stacked-disk” internal membrane morphology with the outer membrane separated in space from the disc membranes. A very short connecting cilium (CC) is present between the OS and the IS: d=~250nm, length=~400nm. Inner segments have multiple mitochondria and terminals have multiple synaptic ribbons. The majority of terminals have 2-3 synaptic ribbons. On rare occasions, terminals possessed 4 synaptic ribbons. Multiple invaginating processes can be identified (~12) and multiple filopodia of varying length extend from the periphery of each terminal.

Conclusions : Skate rods have a typical vertebrate rod OS morphology, but display hybrid characteristics in their inner segments and terminals. CCs are much shorter than in typical rods and resemble those of cones. The presence of multiple ribbons as organizing centers for transmitter release is an unusual characteristic for rods, but can be clearly seen in skate rods, suggesting the evolution of a hybrid morphology to accommodate functional plasticity.

This is a 2021 ARVO Annual Meeting abstract.

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×