Retina: AGB mapping of AMPA/NMDA responses of retinal neurons

Tissue: rabbit retina / vertical sections

Fixation: 250 mM glutaraldehdye, 333 mM paraformaldehyde in 0.1 M phosphate buffer, 3% sucrose

Format: 3 sets of registered serial triplets, 250 nm deplasticized, resin sections

Probes: GABA=RED AGB=GREEN GLUTAMATE=BLUE

Caption: AMPA-activated AGB signals and concurrent GABA, AGB and glutamate signals viewed as GABA:AGB:GLU = RED:GREEN:BLUE mappings in rabbit retina after incubation in Ames medium + 5 mM AGB in presence and absence of glutamate receptor agonists. Data from: Marc RE 1999 Mapping glutamatergic drive in the vertebrate retina with a channel permeant organic cation. J. Comp. Neurol. 407:47-64.
(B) Control. Note the absence of significant basal AGB labeling. In the presence of 5 mM AGB both GABA and glutamate signals are indistinguishable from normal retina.
(D) 100 µM AMPA: Horizontal (h+),bipolar (b+) and amacrine cell (a+) and inner plexiform layer signals are activated. Despite activation of some cells, certain bipolar (b-) and amacrine cells (a-) are either weakly
or completely unresponsive to AMPA.
(E) 1000 µM NMDA: A saturating dose of NMDA activates many elements in the amacrine cell and ganglion cell layers; horizontal and bipolar cells are unresponsive. Abbreviations: a, amacrine cells; b, bipolar cells; h, horizontal cells; Müller cells; mf, Müller cell foot pieces; g, ganglion cell. Scale: 50 µm.

Comparison of AMPA and NMDA activated AGB signals in retina

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