title: [Properties of neurons of the tectal portion of the visual system of the axolotl Ambystoma mexicanum].
abstract: In the tectum opticum of the adult neotenic A. mexicanum, responses of single neuronal units to diffuse illumination and moving visual stimuli have been investigated. Of 111 unites investigated, 27 are presented by tectal neurons, their maximum distribution being observed at a depth of 500-600 mu. In superficial layers 9 ipsi-elements were found; their receptive fields are located in the antero-dorsal part of the visual field, at both sides of the body axis. Among the units identified as the terminals of visual fibers, 70% have receptive fields of 5-10 degrees, being localized in general more close to the surface as compared to the units with the receptive field diameter of 40 and more degrees (11%). Visual neurons and ganglionic retinal cells with axons terminating in the tectum, exhibit poor specificity to the size of a stimulus within 5-30 degrees and do not react to stimuli of 2 degrees.
mesh_terms: D000557:Ambystoma / Q000502:physiology*; D000818:Animals; D001931:Brain Mapping; D004594:Electrophysiology; D009039:Motion Perception / Q000502:physiology*; D012160:Retina / Q000033:anatomy & histology / Q000502:physiology; D013477:Superior Colliculi / Q000502:physiology*; D014795:Visual Pathways / Q000033:anatomy & histology / Q000502:physiology; D014796:Visual Perception / Q000502:physiology*
vernacular_title: Svoĭstva neĭronov tektal'nogo otdela zritel'noĭ sistemy aksolotlia Ambystoma mexicanum.