The retinae of Prototherian mammals possess neuronal types that are characteristic of non-mammalian retinae.
This study has shown that the retinae of Prototherian (egg-laying) mammals possess two neuronal types that are present in non-mammalian retinae, but absent or morphologically different in the retinae of Eutherian (placental) mammals. First, endogenous serotonin-like immunoreactivity has been localized in a population of presumptive amacrine cells in the platypus retina, the first such report in a mammalian retina. Second, the protein kinase C-immunoreactive (PKC-IR) bipolar cells in the echidna retina appear similar to the PKC-IR bipolars in the chicken retina, in that their dendrites give rise to a Landolt's club and their axons are multistratified. By contrast, the PKC-IR rod bipolar cells in the rabbit and in the brushtail possum, a Metatherian (marsupial) mammal, have no Landolt's clubs and their axons form terminal lobes in the innermost stratum of the inner plexiform layer.
Young
H M
HM
Department of Physiology and Pharmacology, University of Queensland, Australia.
Vaney
D I
DI
D000818:Animals; D000911:Antibodies, Monoclonal; D002645:Chickens / Q000033:anatomy & histology; D005455:Fluorescent Antibody Technique; D008322:Mammals / Q000033:anatomy & histology* / Q000145:classification; D009474:Neurons / Q000166:cytology* / Q000378:metabolism; D009893:Opossums / Q000033:anatomy & histology; D010987:Platypus / Q000033:anatomy & histology; D011493:Protein Kinase C / Q000378:metabolism; D012160:Retina / Q000166:cytology* / Q000378:metabolism; D012701:Serotonin / Q000378:metabolism; D013045:Species Specificity; D004442:Tachyglossidae / Q000033:anatomy & histology
D000911:Antibodies, Monoclonal; D012701:Serotonin; D011493:Protein Kinase C