Two groups of TH-like immunoreactive neurons in the frog (Rana pipiens) retina.

The morphology and distribution of TH-like immunoreactive (TH-IR) cells in the retina of Rana pipiens were studied in retinal whole mounts and in radial and horizontal sections. A large majority (96%) of the immunoreactive cells were found in the inner nuclear layer while a few cells were found in the ganglion cell layer. All TH-IR cells had round to oval somata with average diameter of 10 microm.

Differential labelling of primary olfactory system subcomponents by SBA (lectin) and NADPH-d histochemistry in the frog Pipa.

SBA and NADPH-d histochemistries allow identification of functionally distinct components of the amphibian primary olfactory system. In Pipa, a secondarily aquatic frog, combination of both methodologies, using alternate sets of histological sections, reveals that, apart from Jacobson's organ, this species has a "water-nose" and an "air-nose". The epithelia occupy separate chambers of the olfactory organ and give rise to olfactory nerve fiber bundles that are identified by the dual staining procedure.

Antibody to keyhole limpet hemocyanin labels retinal horizontal cells in some amphibians, but not in others.

Antibody to keyhole limpet hemocyanin (KLH) reacts with putative horizontal cells in anuran amphibians of the superfamily Bufonoidea. The reactive epitope appears to be located on the cell membrane. No KLH-like immunoreactivity was observed in the outer plexiform layer (OPL) of anurans not members of this superfamily, nor in the OPL of urodeles or other vertebrates.

Bulbar representation of the 'water-nose' during Xenopus ontogeny.

Olfactory epithelium that is specialized for the detection of water-borne odors is located in different cranial cavities in larval and postmetamorphic Xenopus. Soybean agglutinin histochemistry reveals that both "water-noses' innervate only the ventral olfactory bulb (OB). This is evidence for a parcellation of the OB into a ventral portion mediating information on water-soluble odorants and a dorsal part that processes information on volatile substances.

Soybean agglutinin binding by primary olfactory and primary accessory olfactory projections in different frogs.

Comparing eight species of frogs adapted to habitats ranging from aquatic to arboreal, we observed differences in the affinity of primary olfactory projections to the lectin 'soybean agglutinin'. Particularly pronounced differences exist between Pipa, a frog that rarely leaves the water, and Eleutherodactylus, an arboreal species that does not even utilize aquatic environments for reproduction. We interpret these differences as reflecting specializations to the perception of air-borne vs.