Alterations in neurochemistry during retinal degeneration

Microsc Res Tech. 2000 Jul 15;50(2):89-102. doi: 10.1002/1097-0029(20000715)50:2<89::AID-JEMT1>3.0.CO;2-9.


Retinitis pigmentosa refers to a family of hereditary retinal degenerations that lead to photoreceptor death and vision loss. The underlying cause(s) are not known. In recent years there has been accumulating evidence of neurochemical changes during degeneration. In particular, the amino acids glutamate, GABA, and glycine show alterations in labelling intensity in subsets of neurons. Furthermore, there are differences in the labelling of the precursors, glutamine and aspartate, prior to, during, and following loss of photoreceptors, suggesting that the metabolic pathways involved in neurotransmitter formation and degradation may be abnormal. In addition, there is an elevation in glutamine and arginine content within Müller cells prior to the onset of photoreceptor death. Investigations evaluating Müller cell function indicate that formation and degradation of glutamate, in particular, is abnormal in the degenerating retina from an early age. These studies suggest that even though the primary genetic defect of the RCS rat is within the retinal pigment epithelium, Müller cells develop abnormally, and may contribute to the observed photoreceptor loss.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Animals, Newborn
  • Aspartic Acid / analysis
  • Glutamic Acid / analysis
  • Glutamic Acid / metabolism
  • Glutamic Acid / pharmacology
  • Glutamine / analysis
  • Glycine / analysis
  • Humans
  • Immunohistochemistry
  • Neurotransmitter Agents / analysis*
  • Neurotransmitter Agents / metabolism
  • Photoreceptor Cells, Vertebrate / pathology
  • Rats
  • Retina / growth & development
  • Retina / metabolism
  • Retina / pathology
  • Retinal Degeneration / genetics
  • Retinal Degeneration / metabolism*
  • Retinal Degeneration / pathology
  • Retinitis Pigmentosa / metabolism
  • Time Factors
  • gamma-Aminobutyric Acid / analysis


  • Neurotransmitter Agents
  • Glutamine
  • Aspartic Acid
  • Glutamic Acid
  • gamma-Aminobutyric Acid
  • Glycine