Stratified organization and disorganization of inner plexiform layer revealed by TNAP activity in healthy and diabetic rat retina

Orsolya Kántor, Alexandra Varga, Róbert Tóth, Anna Énzsöly, Emese Pálfi, Tamás Kovács-Öller, Roland Nitschke, Ágoston Szél, Andrea Székely, Béla Völgyi, László Négyessy, Zoltán Somogyvári, Ákos Lukáts

Research output: Contribution to journalArticle

5 Citations (Scopus)


Tissue non-specific alkaline phosphatase (TNAP), an abundant ectophosphatase, is present in various organs including the brain and retina of several vertebrate species. Evidence is emerging that TNAP influences neural functions in multiple ways. In rat, strong TNAP activity has been found in retinal vessels, photoreceptors, and both synaptic layers. In the present study, we identified eleven strata of the inner plexiform layer (IPL) by using TNAP histochemistry alone. The TNAP strata corresponded exactly to the strata seen after combined immunohistochemistry with four canonical IPL markers (TH-ChAT-CR-PKCα). Therefore, as described in other mammalian species, our data support the existence of multiple morphologically and functionally discernible IPL strata in rats. Remarkably, the stratification pattern of the IPL was severely disrupted in a diabetic rat model, even before changes in the canonical IPL markers were detectable. These findings indicate that TNAP histochemistry offers a more straightforward, but also more sensitive, method for investigating retinal strata and their diabetes-induced degeneration.

Original languageEnglish
Pages (from-to)409-421
Number of pages13
JournalCell And Tissue Research
Issue number2
Publication statusPublished - Jan 1 2015



  • Activity-dependent enzyme
  • Biomarker
  • Parallel visual pathways
  • Rat
  • Streptozotocin-induced diabetes
  • Synaptic transmission

ASJC Scopus subject areas

  • Pathology and Forensic Medicine
  • Histology
  • Cell Biology

Cite this