Wide-field nondirectional visual units in the pretectum: do they suppress ocular following of saccade-induced visual stimulation.
1. Direction-selective neurons in the nucleus of the optic tract (NOT) provide motion signals for controlling ocular following responses. When stimulated at low temporal and high spatial frequencies of motion (slow speeds), these retinal-slip neurons produce directional responses. When stimulated by motion at high temporal and low spatial frequencies (the visual conditions during saccades) the spontaneous activities of the neurons are inhibited by motion in all directions. A second class of neurons in, or near, the NOT have large receptive fields, are nondirectional, and are tuned to detect the same spatial and temporal stimuli that induce nondirectional inhibition in the retinal-slip neurons. We suggest that the nondirectional cells provide an inhibitory input for the retinal-slip neurons and therefore prevent ocular following of the visual displacements that accompany saccades.
Ibbotson
M R
MR
Developmental Neurobiology Group, Research School of Biological Sciences, Australian National University, Canberra.
Mark
R F
RF
D000818:Animals; D001288:Attention / Q000502:physiology; D001931:Brain Mapping; D007614:Macropodidae; D009039:Motion Perception / Q000502:physiology*; D009433:Neural Inhibition / Q000502:physiology; D009474:Neurons / Q000502:physiology; D009900:Optic Nerve / Q000502:physiology; D009949:Orientation / Q000502:physiology*; D012160:Retina / Q000502:physiology; D012438:Saccades / Q000502:physiology*; D013028:Space Perception / Q000502:physiology; D013477:Superior Colliculi / Q000502:physiology*; D009435:Synaptic Transmission / Q000502:physiology*; D014794:Visual Fields / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology