April 2011
Volume 52, Issue 14
Free
ARVO Annual Meeting Abstract  |   April 2011
Axonal Synapses of Calbindin ON Bipolar Cells in the OFF Layer of the Rabbit Retina
Author Affiliations & Notes
  • In-Beom Kim
    Department of Anatomy,
    The Catholic University of Korea, Seoul, Republic of Korea
  • Hong-Lim Kim
    Department of Anatomy,
    Integrative Research Support Center,
    The Catholic University of Korea, Seoul, Republic of Korea
  • Ji Hyun Jeon
    Department of Anatomy,
    The Catholic University of Korea, Seoul, Republic of Korea
  • Tae Hyung Koo
    Department of Ophthalmology,
    The Catholic University of Korea, Seoul, Republic of Korea
  • Myung-Hoon Chun
    Department of Anatomy,
    The Catholic University of Korea, Seoul, Republic of Korea
  • Jung-Il Moon
    Department of Ophthalmology,
    The Catholic University of Korea, Seoul, Republic of Korea
  • Footnotes
    Commercial Relationships  In-Beom Kim, None; Hong-Lim Kim, None; Ji Hyun Jeon, None; Tae Hyung Koo, None; Myung-Hoon Chun, None; Jung-Il Moon, None
  • Footnotes
    Support  National Research Foundation of Korea Grant #20100022317, Medical Research Center Grant R13-2002-005-01002-9
Investigative Ophthalmology & Visual Science April 2011, Vol.52, 3028. doi:https://doi.org/
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      In-Beom Kim, Hong-Lim Kim, Ji Hyun Jeon, Tae Hyung Koo, Myung-Hoon Chun, Jung-Il Moon; Axonal Synapses of Calbindin ON Bipolar Cells in the OFF Layer of the Rabbit Retina. Invest. Ophthalmol. Vis. Sci. 2011;52(14):3028. doi: https://doi.org/.

      Download citation file:


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

      ×
  • Supplements
Abstract

Purpose: : Bipolar and ganglion cells whose axon terminals and dendrites stratify in sublamina a of the inner plexiform layer (IPL) show OFF responses at light stimuli and those that stratify in sublamina b show ON responses. This stunning relationship between anatomy and physiology is a key principle of retinal organization. However, there are at least 3 types of inner retinal neurons, dopaminergic amacrine cells, intrinsically photosensitive retinal ganglion cells, and bistratified diving ganglion cells which violate this principle. Their main dendrites stratify in sublamina a of the IPL, the OFF sublamina, but physiologically, they have light-driven ON responses. Recently, anatomical studies showed that some ON cone bipolar cells provide ON inputs to these inner retinal neurons in the OFF sublamina (Hoshi et al., 2009; Dumitrescu et al., 2009). In this study, we examined the synaptic connections of the calbindin-immunoreactive ON cone bipolar cell in sublamina a of the IPL in the rabbit retina.

Methods: : Retinas were isolated from New Zealand white rabbits. Using serial ultrathin sections and electron microscopy, eight calbindin labeled ON cone bipolar cell axons were reconstructed.

Results: : All calbindin ON cone bipolar cells (n=8) examined in this study made ribbon synapses onto amacrine and ganglion dendrites in sublamina a of the IPL. Most of these ribbon synapses were found at the border between the inner nuclear layer and the IPL. In total, 24 synapses onto postsynaptic targets were observed, and thus, a calbindin ON cone bipolar cell axon makes, on average, 3 ribbon synapses in sublamina a. At these 24 axonal ribbon synapses, a total of 44 synaptic ribbons were observed and thus, on average, each axonal synapse contained 1.83 ribbons. Interestingly, all these ribbon synapses appeared as monads (see also Hokoc and Mariani, 1987) and 62.5% contained two or more ribbons from the same calbindin bipolar axon.

Conclusions: : These findings suggest that some ON cone bipolar cells provide ON signals to certain amacrine and ganglion cells whose dendrites stratify in the OFF sublamina. The presence of a monadic ribbon synapse may be a diagnostic feature of ON cone bipolar output in sublamina a.

Keywords: bipolar cells • retina: proximal (bipolar, amacrine, and ganglion cells) • microscopy: electron microscopy 
×
×

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.

×