Increased noise level of purkinje cell activities minimizes impact of their modulation during sensorimotor control.
While firing rate is well established as a relevant parameter for encoding information exchanged between neurons, the significance of other parameters is more conjectural. Here, we show that regularity of neuronal spike activities affects sensorimotor processing in tottering mutants, which suffer from a mutation in P/Q-type voltage-gated calcium channels. While the modulation amplitude of the simple spike firing rate of their floccular Purkinje cells during optokinetic stimulation is indistinguishable from that of wild-types, the regularity of their firing is markedly disrupted. The gain and phase values of tottering's compensatory eye movements are indistinguishable from those of flocculectomized wild-types or from totterings with the flocculus treated with P/Q-type calcium channel blockers. Moreover, normal eye movements can be evoked in tottering when the flocculus is electrically stimulated with regular spike trains mimicking the firing pattern of normal simple spikes. This study demonstrates the importance of regularity of firing in Purkinje cells for neuronal information processing.
Hoebeek
F E
FE
Department of Neuroscience, Erasmus MC, Dr. Molenwaterplein 50, P.O. Box 1738, 3000 DR Rotterdam, The Netherlands. f.hoebeek@erasmusmc.nl
Stahl
J S
JS
van Alphen
A M
AM
Schonewille
M
M
Luo
C
C
Rutteman
M
M
van den Maagdenberg
A M J M
AM
Molenaar
P C
PC
Goossens
H H L M
HH
Frens
M A
MA
De Zeeuw
C I
CI
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D016477:Artifacts; D002121:Calcium Channel Blockers / Q000494:pharmacology; D020865:Calcium Channels, P-Type / Q000187:drug effects / Q000235:genetics*; D002525:Cerebellar Cortex / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D004558:Electric Stimulation; D005133:Eye Movements / Q000502:physiology*; D005246:Feedback / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D008818:Mice, Neurologic Mutants; D017120:Nystagmus, Optokinetic / Q000502:physiology; D009847:Olivary Nucleus / Q000502:physiology; D010775:Photic Stimulation; D011689:Purkinje Cells / Q000187:drug effects / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology; D014726:Vestibular Nuclei / Q000502:physiology; D014796:Visual Perception / Q000502:physiology
D002121:Calcium Channel Blockers; D020865:Calcium Channels, P-Type