Cerebellar LTD and pattern recognition by Purkinje cells.
Many theories of cerebellar function assume that long-term depression (LTD) of parallel fiber (PF) synapses enables Purkinje cells to learn to recognize PF activity patterns. We have studied the LTD-based recognition of PF patterns in a biophysically realistic Purkinje-cell model. With simple-spike firing as observed in vivo, the presentation of a pattern resulted in a burst of spikes followed by a pause. Surprisingly, the best criterion to distinguish learned patterns was the duration of this pause. Moreover, our simulations predicted that learned patterns elicited shorter pauses, thus increasing Purkinje-cell output. We tested this prediction in Purkinje-cell recordings both in vitro and in vivo. In vitro, we found a shortening of pauses when decreasing the number of active PFs or after inducing LTD. In vivo, we observed longer pauses in LTD-deficient mice. Our results suggest a novel form of neural coding in the cerebellar cortex.
Steuber
Volker
V
Laboratory of Theoretical Neurobiology, University of Antwerp, B 2610 Antwerp, Belgium. v.steuber@herts.ca.uk
Mittmann
Wolfgang
W
Hoebeek
Freek E
FE
Silver
R Angus
RA
De Zeeuw
Chris I
CI
Häusser
Michael
M
De Schutter
Erik
E
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D000831:Animals, Newborn; D002525:Cerebellar Cortex / Q000166:cytology*; D004307:Dose-Response Relationship, Radiation; D004558:Electric Stimulation; D066298:In Vitro Techniques; D036881:Long-Term Synaptic Depression / Q000502:physiology*; D008297:Male; D008959:Models, Neurological; D018408:Patch-Clamp Techniques / Q000379:methods; D046709:Pattern Recognition, Physiological / Q000502:physiology*; D011689:Purkinje Cells / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time / Q000502:physiology / Q000528:radiation effects