title: Identified retinal axons occupy postsynaptic positions in the optic tectum of Bufo marinus.
abstract: Horseradish peroxidase was applied to the proximal stump of the cut optic nerve, and the anterogradely transported tracer was visualised by the cobalt-intensified diaminobenzidine method. The optic fibre receiving laminae of the optic tectum were systematically searched for those synapses in which the tracer-filled profiles occupied postsynaptic positions. Optic terminals were rarely but regularly postsynaptic to unlabelled, small clear vesicle-containing profiles, mostly in lamina A. Quantitative analysis showed that only in 0.95% of the synapses formed by optic fibres could this arrangement be substantiated. These results suggest that presynaptic modulatory mechanisms may play a role in optic information processing.
authors.affiliation: Department of Zoology, Janus Pannonius University, Pécs, Hungary.
authors.forename: R
authors.initials: R
authors.lastname: Gábriel
authors.forename: C
authors.initials: C
authors.lastname: Straznicky
mesh_terms: D000818:Animals; D001369:Axons; D002024:Bufo marinus; D008854:Microscopy, Electron; D012160:Retina; D013477:Superior Colliculi / Q000166:cytology*; D013569:Synapses; D013570:Synaptic Membranes; D009435:Synaptic Transmission