Brain Stem Neural Circuits of Horizontal and Vertical Saccade Systems and their Frame of Reference
| Autor: | Yoshikazu Shinoda, Mayu Takahashi |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Superior Colliculi genetic structures Computer science Population Models Neurological 03 medical and health sciences 0302 clinical medicine Neural Pathways otorhinolaryngologic diseases medicine Saccades Animals Humans education Vestibular system Motor Neurons education.field_of_study Semicircular canal General Neuroscience Superior colliculus Eye movement Reflex Vestibulo-Ocular Saccadic masking 030104 developmental biology medicine.anatomical_structure Saccade sense organs Neuroscience 030217 neurology & neurosurgery Brain Stem |
| Zdroj: | Neuroscience. 392 |
| ISSN: | 1873-7544 |
| Popis: | Sensory signals for eye movements (visual and vestibular) are initially coded in different frames of reference but finally translated into common coordinates, and share the same final common pathway, namely the same population of extraocular motoneurons. From clinical studies in humans and lesion studies in animals, it is generally accepted that voluntary saccadic eye movements are organized in horizontal and vertical Cartesian coordinates. However, this issue is not settled yet, because neural circuits for vertical saccades remain unidentified. We recently determined brainstem neural circuits from the superior colliculus to ocular motoneurons for horizontal and vertical saccades with combined electrophysiological and neuroanatomical techniques. Comparing well-known vestibuloocular pathways with our findings of commissural excitation and inhibition between both superior colliculi, we proposed that the saccade system uses the same frame of reference as the vestibuloocular system, common semicircular canal coordinate. This proposal is mainly based on marked similarities (1) between output neural circuitry from one superior colliculus to extraocular motoneurons and that from a respective canal to its innervating extraocular motoneurons, (2) of patterns of commissural reciprocal inhibitions between upward saccade system on one side and downward system on the other, and between anterior canal system on one side and posterior canal system on the other, and (3) between the neural circuits of saccade and quick phase of vestibular nystagmus sharing brainstem burst neurons. In support of the proposal, commissural excitation of the superior colliculi may help to maintain Listing's law in saccades in spite of using semicircular canal coordinate. |
| Databáze: | OpenAIRE |
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