title: Modeling spike-train processing in the cerebellum granular layer and changes in plasticity reveal single neuron effects in neural ensembles.
abstract: The cerebellum input stage has been known to perform combinatorial operations on input signals. In this paper, two types of mathematical models were used to reproduce the role of feed-forward inhibition and computation in the granular layer microcircuitry to investigate spike train processing. A simple spiking model and a biophysically-detailed model of the network were used to study signal recoding in the granular layer and to test observations like center-surround organization and time-window hypothesis in addition to effects of induced plasticity. Simulations suggest that simple neuron models may be used to abstract timing phenomenon in large networks, however detailed models were needed to reconstruct population coding via evoked local field potentials (LFP) and for simulating changes in synaptic plasticity. Our results also indicated that spatio-temporal code of the granular network is mainly controlled by the feed-forward inhibition from the Golgi cell synapses. Spike amplitude and total number of spikes were modulated by LTP and LTD. Reconstructing granular layer evoked-LFP suggests that granular layer propagates the nonlinearities of individual neurons. Simulations indicate that granular layer network operates a robust population code for a wide range of intervals, controlled by the Golgi cell inhibition and is regulated by the post-synaptic excitability.
authors.affiliation: Amrita School of Biotechnology, Amrita University, Kerala, India.
authors.forename: Chaitanya
authors.initials: C
authors.lastname: Medini
authors.forename: Bipin
authors.initials: B
authors.lastname: Nair
authors.forename: Egidio
authors.initials: E
authors.lastname: D'Angelo
authors.forename: Giovanni
authors.initials: G
authors.lastname: Naldi
authors.forename: Shyam
authors.initials: S
authors.lastname: Diwakar
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D002531:Cerebellum / Q000502:physiology*; D008959:Models, Neurological; D009433:Neural Inhibition / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D013569:Synapses / Q000502:physiology*