While research on the cerebellar cortex is crystallizing our understanding of its function in learning behavior, many questions surrounding its downstream targets remain. Here, we evaluate the dynamics of cerebellar interpositus nucleus (IpN) neurons over the course of Pavlovian eyeblink conditioning. A diverse range of learning-induced neuronal responses was observed, including increases and decreases in activity during the generation of conditioned blinks. Trial-by-trial correlational analysis and optogenetic manipulation demonstrate that facilitation in the IpN drives the eyelid movements. Adaptive facilitatory responses are often preceded by acquired transient inhibition of IpN activity that, based on latency and effect, appear to be driven by complex spikes in cerebellar cortical Purkinje cells. Likewise, during reflexive blinks to periocular stimulation, IpN cells show excitation-suppression patterns that suggest a contribution of climbing fibers and their collaterals. These findings highlight the integrative properties of subcortical neurons at the cerebellar output stage mediating conditioned behavior.
Eyelid behavior and spike activity of cerebellar interpositus nucleus neurons during eyeblink conditioning in awake behaving micePublicly available at the Collaborative Research in Computational Neuroscience (http://crcns.org/).
- Zhenyu Gao
- Chris I De Zeeuw
- Javier F Medina
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Animal experimentation: The experiments were approved by the institutional animal welfare committee (Erasmus MC, Rotterdam, The Netherlands). All surgery was performed under isoflurane anaesthesia, and every effort was made to minimize suffering.
- Naoshige Uchida, Harvard University, United States
© 2017, ten Brinke et al.
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