Patterns of glutamate-like immunoreactive bipolar cell axons in the retina of the marine teleost, the dragonet.
Oblique 1 microns-sections through the dorsal inner plexiform layer of the light-adapted dragonet retina were processed for postembedding, silver-enhanced immunogold labeling after incubation with a glutamate-specific antiserum. Light microscopy showed strongly immunolabeled boutons grouped into distinct square patterns. These patterns were compared with the successive grids of bipolar axonal boutons revealed by electron microscope analysis of serial, oblique sections through the entire dorsal inner plexiform layer. With one exception, all types of patterned bipolar synaptic boutons could be clearly identified in the immunoreactive staining pattern. The elevated levels of endogenous glutamate in most bipolar synaptic boutons suggest that the large majority of bipolar cell types use glutamate as their neurotransmitter. However, some bipolar synaptic boutons displaying low levels of glutamate indicate that a small number of bipolar cells may contain another neuroactive substance.
Van Haesendonck
E
E
Eye Research Laboratory, Catholic University of Leuven, Belgium.
Missotten
L
L
D000818:Animals; D001369:Axons / Q000737:chemistry* / Q000648:ultrastructure; D005399:Fishes / Q000033:anatomy & histology / Q000378:metabolism*; D005971:Glutamates / Q000032:analysis*; D018698:Glutamic Acid; D007150:Immunohistochemistry; D012160:Retina / Q000737:chemistry* / Q000648:ultrastructure; D013572:Synaptic Vesicles / Q000737:chemistry / Q000648:ultrastructure
D005971:Glutamates; D018698:Glutamic Acid