Increases of excitatory receptive fields of retinal ganglion cells in common toads under apomorphine are not associated with size preference in prey-snapping.
After systemic administration of the dopamine agonist apomorphine (APO) in common toads Bufo bufo spinosus, the excitatory receptive fields of retinal R2 and R3 ganglion cells doubled their size and the response activities of these neurons to moving visual stimuli were generally increased. Comparable investigations of the stimulus-response relationships in the snapping behavior of toads pre- and post-APO showed a general increase in the snapping responses, but no shift in the preferred prey size. This is consistent with the current concept, suggesting that size evaluation in amphibians does not rely on retinal ganglion cell output but on interacting networks beyond the retina.
Glagow
M
M
Abteilung Neurobiologie/FB 19, Universität Kassell GhK, Germany.
Ewert
J P
JP
D000818:Animals; D001058:Apomorphine / Q000494:pharmacology*; D002023:Bufo bufo; D004594:Electrophysiology; D011235:Predatory Behavior / Q000187:drug effects / Q000502:physiology*; D012165:Retinal Ganglion Cells / Q000187:drug effects / Q000502:physiology*; D012858:Size Perception / Q000187:drug effects / Q000502:physiology*; D014794:Visual Fields / Q000187:drug effects / Q000502:physiology*
D001058:Apomorphine