Climbing Fiber Input Shapes Reciprocity of Purkinje Cell Firing

Neuron. 2013 May 22;78(4):700-13. doi: 10.1016/j.neuron.2013.03.018. Epub 2013 May 2.

Abstract

The cerebellum fine-tunes motor activity via its Purkinje cell output. Purkinje cells produce two different types of spikes, complex spikes and simple spikes, which often show reciprocal activity: a periodical increase in complex spikes is associated with a decrease in simple spikes, and vice versa. This reciprocal firing is thought to be essential for coordinated motor behavior, yet how it is accomplished is debated. Here, we show in Ptf1a::cre;Robo3(lox/lox) mice that selectively rerouting the climbing fibers from a contralateral to an ipsilateral projection reversed the complex-spike modulation during sensory stimulation. Strikingly, modulation of simple spikes, which is supposed to be controlled by mossy fibers, reversed as well. Climbing fibers enforce this reciprocity in part by influencing activity of inhibitory interneurons, because the phase of their activity was also converted. Ptf1a::cre;Robo3(lox/lox) mice showed severe ataxia highlighting that climbing fiber input and its impact on reciprocity of Purkinje cell firing play an important role in motor coordination.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials / physiology
  • Animals
  • Ataxia / physiopathology*
  • Cerebellum / cytology
  • Cerebellum / metabolism*
  • Efferent Pathways / cytology
  • Efferent Pathways / metabolism*
  • Functional Laterality
  • Gene Knock-In Techniques
  • Membrane Proteins / deficiency
  • Membrane Proteins / metabolism*
  • Mice
  • Mice, Knockout
  • Mice, Neurologic Mutants
  • Nerve Tissue Proteins / deficiency
  • Nerve Tissue Proteins / metabolism*
  • Neural Inhibition / physiology
  • Olivary Nucleus / cytology
  • Olivary Nucleus / metabolism*
  • Purkinje Cells / metabolism*

Substances

  • Membrane Proteins
  • Nerve Tissue Proteins
  • Robo3 protein, mouse