Multiplexed coding by cerebellar Purkinje neurons

Abstract

Purkinje cells (PC), the sole output neurons of the cerebellar cortex, encode sensorimotor information, but how they do it remains a matter of debate. Here we show that PCs use a multiplexed spike code. Synchrony/spike time and firing rate encode different information in behaving monkeys during saccadic eye motion tasks. Using the local field potential (LFP) as a probe of local network activity, we found that infrequent pause spikes, which initiated or terminated intermittent pauses in simple spike trains, provide a temporally reliable signal for eye motion onset, with strong phase-coupling to the β/γ band LFP. Concurrently, regularly firing, non-pause spikes were weakly correlated with the LFP, but were crucial to linear encoding of eye movement kinematics by firing rate. Therefore, PC spike trains can simultaneously convey information necessary to achieve precision in both timing and continuous control of motion.DOI: http://dx.doi.org/10.7554/eLife.13810.001

Selective Optogenetic Control of Purkinje Cells in Monkey Cerebellum

“…This result contrasts with the use of optical stimulation as a means to reinforce a learned behavior across trials (Stauffer et al, 2016). We conclude that the precise temporal control afforded by optogenetics can be exploited to manipulate the signals carried by primate Purkinje cells, a population of neurons for which spike timing is thought to be critical for normal function (De Schutter and Steuber, 2009; Hong et al, 2016). …”

Firing Rate-dependent Phase Responses of Purkinje Cells Support Transient Oscillations

“…Although it remains unclear whether the population of PCs converging onto a same cerebellar nuclei (CN) neuron are homogeneous or heterogeneous (Uusisaari and De Schutter, 2011), simultaneous bidirectional PC rate changes have been observed during cerebellumrelated behaviors (Chen et al, 2016;Herzfeld et al, 2015). It is very likely that neighboring PCs show heterogeneous spike rate changes (Hong et al, 2016), which can reduce spike correlations (Markowitz et al, 2008). Therefore, we distributed 10-30 extra cells with decreasing spike rates (Fig.…”

“…The first is that synchronized pauses of PC firing will release CN neurons from inhibition, leading to rebound firing (De Schutter and Steuber, 2009;Lee et al, 2015). There is strong evidence that this mechanism works in controlling the onset of movement in the conditioned eyeblink reflex (Heiney et al, 2014) and in saccade initiation (Hong et al, 2016). The other solution provides a more continuous rate modulated CN output by time-locking of CN spikes to PC input.…”

Forum neurologicum der Deutschen Gesellschaft für Neurologie

“…Aktuelle Publikationen geben Einblicke in basale Hirnfunktionen, z. B. die Rolle des Kleinhirns bei der Sakkaden-Adaptation, die neurale Mechanismen motorischen Lernens widerspiegelt [13]. Viele dieser Erkenntnisse können heute klinisch genutzt werden.…”