ABSTRACT
I. Introduction 52
II. Animal Models and Human Neurological Disorders 52
III. Anatomical Organization of the Olivo-Cerebellar System 52
A. Cerebellar Cortical Output is Organized into Specific
“Modules” or “Zones” 53
B. Cerebellar Cortical Modules Project to Specific Regions of the
Cerebellar and Thalamic Nuclei and Cerebral Cortical Areas 53
C. Somatotopy in the Cerebellum 55
D. Different Subdivisions of the ION Project to Specific Areas of
Somatotopically Defined Areas of Cerebellar Cortical Modules 57
IV. Harmaline-Induced Tremor May be Mediated by the Ventral
Fold of Dao and Caudal Mao of the Ion and Their
Cerebellar Cortical Modules 57
A. Anatomical and Neuroimaging Evidence for Olivary
Involvement in Harmaline-Induced Tremor 57
B. Electrophysiological Evidence for Olivary Involvement
in Tremor 58
V. Harmaline-Induced Tremor and Serotonin 59
VI. Harmaline-Induced Tremor in Animals and Essential Tremor 61
VII. Conclusions 62
Acknowledgment 63
References 63
I. INTRODUCTION
Essential tremor is one of the most common movement disorders. The major
manifestation of essential tremor is a postural or kinetic tremor affecting predo-
minantly the hands, head, and the voice at a frequency of 4-12 Hz. A significant
number of patients report a positive family history of essential tremor, but many
sporadic cases are also seen (1). Despite the use of a wide variety of drugs to
control these tremors, medical treatment has been far less satisfactory (1,2)
than deep brain stimulation (DBS) of the nucleus ventralis intermedialis (VIM)
of the thalamus which provides remarkable improvement in tremor and the
disabilities associated with essential tremor in almost all patients (3).
