Morphological and immunocytochemical identification of indoleamine-accumulating neurons in the cat retina

J Neurosci. 1987 May;7(5):1574-85. doi: 10.1523/JNEUROSCI.07-05-01574.1987.


The type and distribution of indoleamine-accumulating neurons were studied in the cat retina. The neurons were characterized by their capacity to take up an exogenous indoleamine, 5,6-dihydroxytryptamine, which could then be visualized using formaldehyde-induced fluorescence. Under direct microscopic control, intracellular injection of Lucifer yellow into the labeled cells revealed that the indoleamine-accumulating neurons comprise 2 distinct morphological types of amacrine cell and 1 class of ganglion cell. The dendritic morphology and retinal distribution of these cells were studied in detail. The proportion of retinal cells that accumulate 5-HT was measured using 5-HT (5-hydroxytryptamine) preloading in vitro and immunocytochemistry with an anti-5-HT antibody. Only 1 type of amacrine cell showed uptake of 5-HT at a concentration of 10(-7) M. Cells containing endogenous 5-HT were not detected by immunocytochemistry.

MeSH terms

  • 5,6-Dihydroxytryptamine / metabolism*
  • Animals
  • Cats
  • Dendrites / metabolism
  • Fluorescent Antibody Technique
  • Histocytochemistry
  • Immunoenzyme Techniques
  • In Vitro Techniques
  • Retina / cytology
  • Retina / metabolism*
  • Serotonin / metabolism*


  • Serotonin
  • 5,6-Dihydroxytryptamine