The Vestibular System

I. Introduction ; Chapter 1- The Vestibular System in Everyday Life ; 1.1 Overview of the vestibular system ; 1.2 Visual acuity and the vestibulo-ocular reflex ; 1.3 Air-righting reflex in the cat ; 1.4 Post-rotational reactions ; 1.5 Positional alcohol nystagmus (PAN) ; 1.6 Motion sickness ; 1.7 Vection illusions ; 1.8 The subjective visual vertical ; 1.9 Adaptive plasticity ; 1.10 Path finding and spatial orientation ; 1.11 Postural control ; 1.12 Summary ; 1.13 Selected readings ; II. Peripheral Vestibular System ; Chapter 2 - Structure of the Vestibular Labyrinth ; 2.1 Gross and microscopic anatomy ; 2.2 Fine structure of the sensory regions ; Hair cells ; Supporting cells ; Transitional regions ; 2.3 Regional variations in cellular architecture and afferent innervation ; Cristae ampullares ; Utricular macula ; Saccular macula ; 2.4 Efferent innervation ; 2.5 Summary ; 2.6 Selected readings ; Chapter 3- Hair Cell Transduction ; 3.1 Mechanoelectric transduction ; 3.2 Basolateral currents ; 3.3 Neurotransmitter release and presynaptic calcium ; channels ; Calcium channels ; Neurotransmitter release. ; 3.4 Postsynaptic mechanisms ; 3.5 Synaptic transmission involving type I hair cells ; 3.6 Spike encoding ; 3.7 Efferent neurotransmission ; 3.8 Summary ; 3.9 Selected readings ; Chapter 4- Physiology of the Vestibular Organs ; 4.1 General features of the vestibular organs ; Vestibular organs are inertial sensors ; Resting discharge ; Discharge regularity ; Information transmission ; 4.2 Semicircular canals ; Directional properties ; Macromechanics and the torsion-pendulum model ; Interspecies variations and canal dimensions ; Afferent response dynamics ; Variations in gain and phase ; Afferent morphology and physiology ; Dynamic range of afferent discharge ; 4.3 Otolith organs ; Directional properties ; Macromechanics and the otoconial membrane ; Afferent response dynamics ; Dynamic range of afferent discharge ; Variations in gain and phase ; Afferent morphology and physiology ; 4.4 Summary ; 4.5 Selected readings ; Chapter 5- The Efferent Vestibular System ; 5.1 Comparative anatomy of central efferent pathways ; 5.2 Responses of afferents to electrical stimulation of ; EVS ; Mammals. ; Non-mammals ; 5.3 Responses of efferents to natural stimulation ; 5.4 Efferent-mediated responses of afferents ; 5.5 Possible functions of efferents in mammals ; 5.6 Summary ; III. Central Vestibular System ; Chapter 6 - Neuroanatomy of Central Vestibular Pathways ; 6.1 Introduction ; 6.2 The vestibular nuclei: subdivisions and anatomical ; organization ; Medial vestibular nucleus (MVN) ; Lateral vestibular nucleus (LVN) ; Superior vestibular nucleus (SVN) ; Descending vestibular nucleus (DVN) ; y group ; Interstitial nucleus of the vestibular nerve (INT8) ; Associated cell groups (z, x, f, l,m) ; Projection and intrinsic neurons ; Connections with the ipsilateral vestibular nerve ; Commissural pathways ; 6.3 Vestibulo-ocular and optokinetic systems ; Semicircular canal projections to oculomotor neurons ; Otolith projections to oculomotor neurons ; Nucleus prepositus hypoglossi (NPH) ; Interstitial nucleus of Cajal (INC) ; Reticular formation ; Optokinetic pathways ; 6.4 Vestibulospinal systems ; Medial vestibulospinal tract (MVST) ; Lateral vestibulospinal tract (LVST) ; Vestibulo-ocular cervical pathways (VOC) ; Other vestibulospinal tracts ; Spinal projections to the vestibular nuclei ; 6.5 Vestibulocerebellar relations ; Basic circuitry ; Vestibular projections to the cerebellum ; Prepositus nucleus ; Projections from the deep cerebellar nuclei to the ; vestibular nuclei ; Projections from the cerebellar cortex to the vestibular ; nuclei ; Cerebellar cortical modules ; Lateral reticular nucleus ; Vestibulo-paramedian tract projections ; 6.6 Vestibulo-autonomic connections ; 6.7 Vestibular connections with the neocortex ; 6.8 Pathways involving the hippocampal formation ; 6.9 Summary ; 6.10 Selected readings ; 6.11 List of abbreviations ; Chapter 7 -Synaptic Mechanisms in the Vestibular Nuclei ; 7.1 Historical perspective ; 7.2 Basic circuitry of the vestibular nuclei ; Ipsilateral vestibular nerve inputs ; Commissural connections ; 7.3 Neurotransmitters in the vestibular nuclei ; Transmission between the vestibular nerve and secondary ; neurons ; Transmission within the vestibular nucleus ; Output pathways of the vestibular nuclei ; 7.4 Properties of individual neurons ; Resting discharge ; 7.5 Central projections of regular and irregular afferents ; Electrophysiological studies ; Functional ablation of irregular afferents ; 7.6 Convergence from separate vestibular organs ; Convergence from separate vestibular organs ; Canal-canal convergence ; Otolith-otolith convergence ; Spatio-temporal convergence ; Canal-otolith convergence ; Convergence from somatosensory receptors ; 7.7 Summary ; 7.8 Selected readings ; IV. Vestibulo-ocular and Vestibulopinal Mechanisms ; Chapter 8 - An Oculomotor Tutorial ; 8.1 Overview and classification of eye movement types ; 8.2 Ocular structure and functional implications ; The extraocular eye muscles. ; Mechanics of the oculomotor plant ; Oculomotor motoneuron discharge. ; Plant mechanics and premotor control. ; 8.3 Gaze Redirection ; Saccades ; Smooth pursuit ; Vergence ; 8.4 Gaze Stabilization ; Vestibulo-ocular reflexes. ; Optokinetic system. ; 8. 5 Interactions between eye and head movements ; 8.6 Summary ; 8.7 Selected readings ; Chapter 9 -Vestibulo-ocular Reflexes ; 9.1. Semicircular-canal related angular VOR (AVOR) ; General properties of the canal-related AVOR. ; AVOR during high frequency rotations. ; AVOR at low frequencies - velocity storage. ; AVOR-visual interactions: the optokinetic system. ; AVOR in three-dimensions. ; 9.2. Otolith-ocular reflexes ; Tilt VOR. ; Otolith influences on the AVOR during off-vertical axis ; rotations (OVAR). ; Otolith influences on the AVOR during canal/otolith ; conflict. ; Translational VOR (TVOR). ; Optic flow during translation. ; Visual mechanisms for short latency visual compensation ; during translation. ; Distinguishing tilts from translations. ; Differences between the AVOR and the TVOR. ; Functional differences: Foveal rather than full-field image ; stabilization. ; Dependence on viewing distance and eye position. ; Response latency and neural pathways. ; Comparative adaptation ; 9.3 Summary ; 9.4 Selected readings ; Chapter 10-The Vestibulospinal System and Postural Control ; 10.1. Reflexes versus multisensory strategies ; 10.2 Multisensory strategies ; 10.3. Vestibular reflexes: general considerations ; 10.4 Vestibulocollic reflexes ; The angular VCR. ; The linear VCR evoked by translation and tilts. ; The cervicocollic reflex ; 10.5. Control systems analysis of the head-neck plant. ; Head plant. ; Vestibulocollic reflex. ; The cervicocollic reflex ; Reflex interactions. ; Use of control systems models ; 10.6. Vestibulospinal and neck reflexes acting on the ; limbs ; Spatial and temporal properties of the reflexes. ; Afferent origin of the reflexes ; Neural substrate of the reflexes. ; Vestibulospinal actions on hindlimb motoneurons. ; Vestibulospinal actions on forelimb motoneurons. ; Tonic neck reflexes. ; 10.7 Summary ; 10.8 Selected readings ; V. Signal Processing in Alert Animals ; Chapter 11- Signal Processing in Vestibular Nuclei of Alert ; Animals During Natural Behaviors ; 11.1 Introduction ; 11.2 Classes of neurons in head-restrained, alert monkeys ; Position-vestibular-pause (PVP) neurons. ; Vestibular-only (VO) and vestibular-pause cells. ; Eye-head (EH) neurons. ; Burst-tonic (BT) neurons. ; 11.3 Dynamics of neuronal responses ; Frequency response during sinusoidal rotations ; Response linearity ; Velocity storage ; 11.4 Response to linear translations in alert ; head-restrained monkeys ; Distinguishing translational from tilt. ; 11.5 Interactions with the oculomotor pathways that control ; pursuit eye movements ; 11.6 Integration of inputs from vestibular and optokinetic ; pathways ; VN modulation during the OKR ; Optokinetic pathways to the VN. ; 11.7 Integration of vestibular and proprioceptive inputs ; 11.8 Differential processing of active versus passive head ; movements ; Neuronal responses during active versus passive head ; movement. ; Mechanisms for the differential processing of ; actively-generated versus passive head movement. ; 11.9 Vestibular processing depends on current gaze ; strategy. ; Vestibular processing during voluntary gaze shifts. ; Vestibular processing during visual tracking; VOR ; cancellation and eye-head pursuit. ; Vestibular processing during near versus far viewing. ; 11.10 Summary ; 11.11 Selected readings ; Chapter 12 - The Cerebellum and the Vestibular System ; 12. 1 Overview of signal processing in the cerebellum ; The basic cerebellar circuit ; Vestibular inputs are specific to localized regions of the ; cerebellum ; 12.2 Nodulus and Ventral Uvula ; Mossy fiber inputs. ; Climbing fiber inputs. ; Efferent connections. ; Neuronal responses ; Lesions and function. ; 12.3 Flocculus and ventral paraflocculus ; Mossy fiber inputs. ; Climbing fiber inputs ; Efferent projections of the flocculus. ; Differences between the flocculus and ventral ; paraflocculus ; Neuronal responses. ; Complex spikes: ; Simple spikes. ; Changes in neuronal responses following VOR learning ; Lesions and function ; Lesions studies emphasize the role of the flocculus in VOR ; Adaptation and motor learning ; 12.4 The Vermis of the Anterior and Posterior Lobes ; 12.5 The Deep Cerebellar Nuclei ; Fastigial Nucleus. ; Rostral fastigial nucleus ; Caudal fastigial nucleus ; The interposed nuclei. ; Dentate nuclei. ; 12.6 Summary ; 12.7 Selected Readings ; VI..Functional Considerations ; Chapter 13 - Learning and Compensation in the Vestibular ; System ; 13.1 Motor learning in the vestibulo-ocular reflex ; The adaptive capabilities of the VOR. ; Signal flow in the VOR network. ; Rules for the VOR and motor learning. ; Possible sites of motor learning: cerebellum versus brain ; stem ; Evidence for sites of learning and memory. ; Possible cellular mechanisms of synaptic plasticity ; Cerebellar mechanisms ; Brain stem mechanisms ; Consolidation of VOR motor memory ; Generalization: can learning be applied to new situations? ; 13.2. Compensation for vestibular damage ; Uninilateral labyrinthectomy ; Activity in the vestibular nuclei following ; labyrinthectomy ; Cellular mechanisms of compensation in the vestibular ; nuclei ; The role of the cerebellum in compensation ; 13.3 Summary ; 13.4 Selected readings ; Chapter 14-Cortical Representations of Vestibular ; Information ; 14.1. Introduction ; 14.2. Historical Perspective ; 14.3. Multiple representations of vestibular signals in the ; cerebral cortex. ; Visuomotor areas in frontal cortex. ; Extrastriate visual cortex (MSTd). ; Ventral intraparietal (VIP) area ; Parieto-insular vestibular cortex (PIVC), area 2v and area ; 3a ; 14.4. Ascending vestibular pathways through the thalamus ; 14.5 Descending cortical information affecting vestibular ; responsiveness in the vestibular nuclei ; 14.6. Vestibular influences in the head direction circuit of ; the limbic system ; 14.7 Summary ; 14.8 Selected readings ; Chapter 15-Reference Frames Used in the Coding Vestibular ; Information ; 15.1. Definitions of coordinate systems and reference ; frames ; 15.2. Head- versus body-centered reference frames: ; Vestibular/neck proprioceptive interactions ; 15.3. Head- versus eye-centered reference frames for ; self-motion perception: vestibular/visual interactions in ; extrastriate visual cortex ; 15.4. Head- versus world-centered reference frames: ; Canal/otolith convergence for inertial motion detection ; 15.5 Computational solution for the two ambiguities of peripheral ; vestibular sensors ; The rotation problem: allocentric coding of angular velocity ; The linear acceleration problem: evidence for segregation of ; tilt and translation ; Tilt-translation exceptions ; VII. Clinical Disorders ; Chapter 16- Clinical Manifestations of Vestibular ; Dysfunction ; 16.1 Prevalence and impact of vestibular disorders ; 16.2 Diagnosis of vestibular disorders ; 16.3 Planes of individual canals and direction of eye ; movements ; Benign paroxysmal positional vertigo ; Positional alcohol nystagmus ; Superior semicircular canal dehiscence syndrome ; 16.4 Recovery of the horizontal VOR after unilateral ; labyrinthectomy ; 16.5 Multisensory control of posture ; 16.6 Disorders of otolith function ; 16.7 Clinical tests of vestibular function ; Caloric test ; Rotational chair tests ; Quantitative evaluation of the VOR evoked by rapid head ; movements ; Vestibular-evoked myogenic potentials (VEMPs) ; 16.7 Future directions ; Hair-cell regeneration ; Vestibular prosthesis ; 16.8 Summary ; 16.9 Selected readings