Expression of calcium transporters in the retina of the tiger salamander (Ambystoma tigrinum)

David Križaj*, Xiaorong Liu, David R. Copenhagen

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

20 Scopus citations

Abstract

Changes in intracellular calcium concentration, [Ca2+]i, modulate the flow of visual signals across all stages of processing in the retina, yet the identities of Ca2+ transporters responsible for these changes are still largely unknown. In the current study, the distribution of plasma membrane and intracellular Ca2+ transporters in the retina of tiger salamander, a model system for physiological studies of retinal function, was determined. Plasma membrane calcium ATPases (PMCAs), responsible for high-affinity Ca2+ extrusion, were highly expressed in the salamander retina. PMCA isoforms 1, 2, and 4 were localized to photoreceptors, whereas the inner retina expressed all four isoforms. PMCA3 was expressed in a sparse population of amacrine and ganglion neurons, whereas PMCA2 was expressed in most amacrine and ganglion cells. Na+/Ca2+ exchangers, a high-capacity Ca2+ extrusion system, were expressed in the outer plexiform layer and in a subset of inner nuclear and ganglion layer cells. Intracellular Ca2+ store transporters were also represented prominently. SERCA2a, a splice variant of the sarcoplasmic-endoplasmic Ca 2+ ATPase, was found mostly in photoreceptors, whereas SERCA2b was found in the majority of retinal neurons and in glial cells. The predominant endoplasmic reticulum (ER) Ca2+ channels in the salamander retina are represented by the isoform 2 of the IP3 receptor family and the isoform 2 of the ryanodine receptor family. These results indicate that Ca 2+ transporters in the salamander retina are expressed in a cell type-specific manner.

Original languageEnglish (US)
Pages (from-to)463-480
Number of pages18
JournalJournal of Comparative Neurology
Volume475
Issue number4
DOIs
StatePublished - Aug 2 2004

Keywords

  • Amacrine cell
  • Na/Ca exchanger
  • PMCA
  • Photoreceptor
  • Ryanodine receptor
  • SERCA

ASJC Scopus subject areas

  • Neuroscience(all)

Fingerprint Dive into the research topics of 'Expression of calcium transporters in the retina of the tiger salamander (Ambystoma tigrinum)'. Together they form a unique fingerprint.

Cite this