title: Response properties and visual receptive fields of climbing and mossy fibers terminating in the flocculus of the monkey.
abstract: Response properties and visual receptive fields of climbing fibers and mossy fibers terminating in the cerebellar flocculus were studied in monkeys trained to fixate a stationary visual target. Among a total of 429 climbing fiber-related units (climbing fibers and complex spikes of Purkinje cells), 20 (4.9%) showed cyclic modulations in firing in response to sinusoidal retinal-slip velocities. Their receptive fields always included the fovea. Among 485 mossy fibers, 64 (13%) responded to the visual stimulation. Of the 64 visually responsive mossy fiber units, 39 (61%) responded exclusively to the retinal-slip velocity (visual mossy fibers and the remaining 25 mossy fibers (39%) responded also to the eye and head velocities (visuomotor mossy fibers). Receptive fields for 17 visual mossy fibers (17/39 or 44%) were within 10 degrees of fixation and those for 22 others (56%) were in the periphery. Receptive fields for all 25 visuomotor mossy fibers were in the periphery. Each mossy fiber unit had a unique velocity-tuning curve and, therefore, the response patterns of individual mossy fibers were different depending on the range of their velocity sensitivity and on the retinal-slip velocity applied.
mesh_terms: D000200:Action Potentials; D000818:Animals; D001369:Axons / Q000502:physiology; D002531:Cerebellum / Q000502:physiology*; D008254:Macaca nemestrina; D009039:Motion Perception / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology; D010775:Photic Stimulation; D011689:Purkinje Cells / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*