Visuo-vestibular information processing by unipolar brush cells in the rabbit flocculus.
The unipolar brush cell (UBC) is a glutamatergic granular layer interneuron that is predominantly located in the vestibulocerebellum and parts of the vermis. In rat and rabbit, we previously found using juxtacellular labeling combined with spontaneous activity recording that cells with highly regular spontaneous activity belong to the UBC category. Making use of this signature, we recorded from floccular UBCs in both anesthetized and awake rabbits while delivering visuo-vestibular stimulation by using sigmoidal rotation of the whole animal. In the anesthetized rabbit, the activity of the presumed UBC units displayed a wide variety of modulation profiles that could be related to aspects of head velocity or acceleration. These modulation profiles could also be found in the awake rabbit where, in addition, they could also carry an eye position signal. Furthermore, units in the awake rabbit could demonstrate rather long response latencies of up to 0.5 s. We suggest that the UBCs recorded in this study mostly belong to the type I UBC category (calretinin-positive) and that they can play diverse roles in floccular visuo-vestibular information processing, such as transformation of velocity-related signals to acceleration-related signals.
Department of Neuroscience & Physiology, New York University Medical School, New York, NY, 10016, USA.
Robert A
RA
Hensbroek
Department of Neuroscience, Erasmus MC Rotterdam, 3000 CA, Rotterdam, Netherlands. t.ruigrok@erasmusmc.nl.
Tom J H
TJ
Ruigrok
ENT Department, St. Mary's Hospital, London, W2 1NY, UK.
Boeke J
BJ
van Beugen
Brain Trauma Foundation, 1 Broadway, New York, NY, 10004, USA.
Jun
J
Maruta
Department of Neuroscience & Physiology, New York University Medical School, New York, NY, 10016, USA.
John I
JI
Simpson
D000200:Action Potentials / Q000502:physiology; D000465:Algorithms; D000818:Animals; D002525:Cerebellar Cortex / Q000502:physiology*; D007395:Interneurons / Q000502:physiology*; D009412:Nerve Fibers / Q000502:physiology; D009434:Neural Pathways / Q000502:physiology*; D011817:Rabbits / Q000033:anatomy & histology; D014722:Vestibule, Labyrinth / Q000502:physiology*; D014851:Wakefulness
Acceleration; Cerebellum; Eye position; Flocculus; UBC; Velocity