The Oculomotor System of the Rabbit and Its Plasticity

ISBN-13: 9783642816291 / Angielski / Miękka / 2011 / 240 str.

H. Collewijn

Opis

The invitation to contribute a volume to the series Studies in Brain Func tion offers me a welcome opportunity for a comprehensive presentation of my research on the eye movements of the rabbit, and for a review of the older results in the perspectives offered by the progress of my own work, but even more of the field in general. Characteristically this monograph em phasizes the views of the author, which may not always be generally accept ed. Although connections with the work by other investigators are discussed as much as possible, I have not attempted to be complete in reviewing all publications related to oculomotor function in the rabbit. While presenting an overview of current understanding of a system, it is always wise to trace the historical roots of our knowledge and concepts. On the one hand, we may find that many established concepts derive their strength more from convention and convenience than from rigorous evi dence. Such traditional ideas should be challenged by critical experiments, using the best available techniques. On the other hand, some of the older publications remain a source of inspiration, because they contain valid ideas which generate fruitful experiments even today. A remarkable example of this category is Ter Braak's work on optokinetic nystagmus, published in 1936."

Spis treści

1 Introduction.- 1.1 Orientation of the Eyes.- 1.2 Retinal Organization.- 1.3 Visual Acuity.- 2 Eye Movements in Spontaneous Behavior.- 2.1 Techniques.- 2.2 Spontaneous Activity.- 2.3 Structure of Saccades.- 2.4 Intersaccadic Gaze Stability.- 2.5 Active Pursuit.- 2.6 Vergence.- 2.7 Conclusions.- 3 Eye Movements During Passive Oscillation.- 3.1 Rotation Around the Three Principal Axes.- 3.2 Properties of the Horizontal Canal-Ocular Reflex.- 3.3 Visual Suppression of the VOR.- 3.4 Maculo-Ocular Reflexes.- 3.5 Conclusions.- 4 Optokinetic and Postrotatory Nystagmus.- 4.1 The Nature of the Optokinetic Reflex.- 4.2 Optokinetic Responses to Sinusoidal Stimulation.- 4.3 Optokinetic Nystagmus.- 4.4 Open-Loop Optokinetic Nystagmus.- 4.5 Optokinetic Reactions in Different Directions.- 4.6 Vestibulo-Ocular and Optokinetic Responses During and After Rotations at a Constant Velocity.- 4.7 Conclusions.- 5 Signal Processing.- 5.1 Retinal Motion Detection.- 5.2 Relevance of Different Primary Optic Projections for OKN.- 5.2.1 The Geniculo-Cortical Projection.- 5.2.2 The Superior Colliculus.- 5.3 Direction-Selectivity in the Nucleus of the Optic Tract.- 5.4 Direction-Selectivity in the Posterior Accessory Optic System.- 5.5 Efferent Connections from the Nucleus of the Optic Tract.- 5.6 Effects of Bilateral Labyrinthectomy.- 5.7 The Effect of Cerebellectomy on OKN.- 5.8 Modeling of the Rabbit’s Optokinetic System.- 6 Adaptation and its Limits.- 6.1 Unilateral Labyrinthectomy.- 6.2 Dark-Rearing.- 6.2.1 Responses to Sinusoidal Movement in Darkness (VOR).- 6.2.2 Responses to Sinusoidal Movement with Eyes Open (VOR and OKN).- 6.2.3 Optokinetic Nystagmus.- 6.3 Long-Term Adaptation of VOR and OKN.- 6.3.1 Adaptive Phenomena in the VOR.- 6.3.2 Conditions for Visual Adaptation of the VOR.- 6.3.3 Adaptation to Inverted Motion yision, Restricted Visual Field.- 6.3.4 Adaptation to Inverted Motion Vision, Whole Visual Field.- 6.3.5 Adaptation by Visual Stimulation Only.- 6.3.6 Frequency Specificity of Adaptation.- 6.3.7 Adaptation in Synergic Operation of VOR and OKN.- 6.3.8 Conclusions on Adaptation.- 6.4 Optokinetic Anomalies in Albino Rabbits.- 6.4.1 Inverted OKN in Albino Rabbits.- 6.4.2 Anomalous Receptive Fields in the Nucleus of the Optic Tract in Albino Rabbits.- 6.4.3 Adaptation Experiments in Albino Rabbits.- 6.5 Conclusions.- References.- 1 Introduction.- 2 The Optokinetic Nystagmus in the Rabbit.- 2.1 The Conditions for the Eliciting of OKN.- 2.1.1 Size of the Moving Field.- 2.1.2 Velocity of Moving Contrasts.- 2.1.3 Nature of the Stimulus.- 2.2 Slow and Fast Phase.- 2.3 Quantitative Relations Between Stimulus and Effect.- 2.3.1 Equilibrium Between Stimulus and Nystagmus, at Different Velocities of the Moving Contrasts.- 2.3.2 Behavior of Nystagmus at the Beginning and End of Stimulation.- 2.4 A Theoretical Model of the Central Mechanism of Stare Nystagmus.- 2.5 Optokinetic and Vestibular Nystagmus.- 3 Stare Nystagmus in Other Species of Animals.- 4 The Localization of Stare Nystagmus in the Central Nervous System.- 5 Look Nystagmus.- 6 The Localization of Look Nystagmus in the Central Nervous System.- References.