CHAPTER LI 



The cerebellum' 



JOHN M. BROOKHART- 



Department of Physiology, University of Orrgon 

 Medical School, Portland, Oregon 



CHAPTER CONTENTS 



Historical Background 

 Anatomical Orientation 

 Gross Morphology 

 Cortex 

 Nuclei 



Extracerebellar Relations 

 Characteristics of Cerebellar Activity 

 Spontaneous Cerebellar Activity 



Electrical activity of cerebellar surface 

 Activity patterns in cerebellar neurons 

 Cerebellar Activity as Altered by Surface Stimulation 

 Single shocks 

 Repetitive stimulation 

 Cerebellar Activity as Altered by Cerebellopetal Impulses 

 Form of evoked potential 

 Sensory input 



Impulses from cerebral cortex 

 Impulses from brain-stem sources 

 Interactions of sensory volleys 

 Cerebellar Activity as Altered by Drug Actions 

 Topical application 

 Systemic administration 

 Cerebellofugal Activity 

 Cerebellar nuclei 

 Cerebellar peduncles 



Activity secondarily induced by cerebellofugal impulses 

 Perspective 

 Functional Alterations Produced by Cerebellar Stimulation 

 Stimulation of Cerebellar Cortex 

 Electrical stimulation 

 Anterior lobe 

 Posterior lobe 

 Flocculonodular lobe 

 Other forms of stimulation 

 Chemical 

 Mechanical 



' Prepared during the tenure of a grant under the Fulbright 

 Act. 



2 The author wishes to express his sincere gratitude to Dr. 

 G. Moruzzi and Dr. R. S. Dow for their generous permission 

 to study the prepublication manuscript of their major and 

 exhaustive monograph on the physiology and pathology of the 

 cerebellum which appeared in 1957. 



Stimulation of Interior of Cercbellimi 

 Cerebellocerebral Interactions 

 Motor functions 



Electrical activity of cerebral cortex 

 Stimulation Through Chronically-Implanted Electrodes 

 Perspective 

 .Mtcrations of Function Produced by Cerebellar Destruction 

 Introduction 

 Total Ablation 



Signs of inhibitory withdrawal 

 Signs of facilitatory withdrawal 

 Disorders of phasic contractions 

 Unilateral Cerebellar Ablations 

 Signs of inhibitory withdrawal 

 Signs of facilitatory withdrawal 

 Disorders of phasic contractions 

 Localized .Ablations of Portions of Cerebellum 

 Flocculonodular lobe 

 Anterior lobe of corpus cerebcUi 

 Destruction of cortex 

 EfTerent paths 

 Posterior lobe of corpus ccrcbcUi 



Ablations involving most of posterior lobe 

 Partial lesions of posterior lobe 

 EfTerent paths of posterior lobe 

 Perspective 

 Mechanisms of Cerebellar Function 



Mechanisms of Inliuence on Postural Tonus 

 Origins of hypertonus 

 Origins of hypotonia and asthenia 

 Mechanisms of Influence on Phasic Reflexes 

 Mechanisms of Influence on Voluntary Movement 

 Mechanisms of Compensation 

 Cerebellar Deficiencies in Man 



HISTORICAL B.ACKGROUND 



THE STORY OF THE GROWTH of knowledge of the 

 physiology of the cerebellum recapitulates the story 

 of the growth of almost all branches of human knowl- 

 edge. Opinions originally founded on pure specula- 

 tion have been supplanted by opinions based upon 



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