Show Reference: "Gaze Stabilization by Efference Copy Signaling without Sensory Feedback during Vertebrate Locomotion."

Gaze Stabilization by Efference Copy Signaling without Sensory Feedback during Vertebrate Locomotion. Current biology : CB (24 July 2012), doi:10.1016/j.cub.2012.07.019 by François M. Lambert, Denis Combes, John Simmers, Hans Straka
@article{lambert-et-al-2012,
    abstract = {
                {BACKGROUND}: Self-generated body movements require compensatory eye and head adjustments in order to avoid perturbation of visual information processing. Retinal image stabilization is traditionally ascribed to the transformation of visuovestibular signals into appropriate extraocular motor commands for compensatory ocular movements. During locomotion, however, intrinsic "efference copies" of the motor commands deriving from spinal central pattern generator ({CPG}) activity potentially offer a reliable and rapid mechanism for image stabilization, in addition to the slower contribution of movement-encoding sensory inputs. {RESULTS}: Using a variety of in vitro and in vivo preparations of Xenopus tadpoles, we demonstrate that spinal locomotor {CPG}-derived efference copies do indeed produce effective conjugate eye movements that counteract oppositely directed horizontal head displacements during undulatory tail-based locomotion. The efference copy transmission, by which the extraocular motor system becomes functionally appropriated to the spinal cord, is mediated by direct ascending pathways. Although the impact of the {CPG} feedforward commands matches the spatiotemporal specificity of classical vestibulo-ocular responses, the two fundamentally different signals do not contribute collectively to image stabilization during swimming. Instead, when the {CPG} is active, horizontal vestibulo-ocular reflexes resulting from head movements are selectively suppressed. {CONCLUSIONS}: These results therefore challenge our traditional understanding of how animals offset the disruptive effects of propulsive body movements on visual processing. Specifically, our finding that predictive efference copies of intrinsic, rhythmic neural signals produced by the locomotory {CPG} supersede, rather than supplement, reactive vestibulo-ocular reflexes in order to drive image-stabilizing eye adjustments during larval frog swimming, represents a hitherto unreported mechanism for vertebrate ocular motor control.
                Copyright {\copyright} 2012 Elsevier Ltd. All rights reserved.
            },
    author = {Lambert, Fran\c{c}ois M. and Combes, Denis and Simmers, John and Straka, Hans},
    day = {24},
    doi = {10.1016/j.cub.2012.07.019},
    issn = {1879-0445},
    journal = {Current biology : CB},
    keywords = {biology, eye-movements, motor, vestibulo-ocular-reflex},
    month = jul,
    pmid = {22840517},
    posted-at = {2012-09-25 08:51:17},
    priority = {2},
    title = {Gaze Stabilization by Efference Copy Signaling without Sensory Feedback during Vertebrate Locomotion.},
    url = {http://dx.doi.org/10.1016/j.cub.2012.07.019},
    year = {2012}
}

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Tadpoles make eye movements which compensate for swimming movements independent of visual or vestibular input. Their rhythmic swimming motor commands are generated by spinal central pattern generators (CGPs). Efference copies of these motor commands appear to be what induces the eye movements.