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  • Open Access

A biophysical model of cerebellar molecular layer interneuron

BMC Neuroscience201314 (Suppl 1) :P96

https://doi.org/10.1186/1471-2202-14-S1-P96

  • Published:

Keywords

  • Purkinje Cell
  • Molecular Layer
  • Cerebellar Cortex
  • Biophysical Model
  • Input Capacitance

The molecular layer of the cerebellum is characterized by small interneurons (basket and stellate cells). They exert a strong inhibition on their postsynaptic Purkinje cell targets [1]. They are known to be present in large numbers in the molecular layer. They outnumber the Purkinje cells by a factor of 10 [2]. Gap junctions between them characterize the interneurons of the cerebellar cortex. The interneurons are also known to inhibit each other. The extensive connectivity network between the interneurons and with that of the Purkinje cells, make the interneurons of the molecular layer a vital component in determining the output of the Purkinje cells.

We constructed a biophysical model of molecular layer interneuron of the cerebellar cortex in order to study them more extensively at network level. The model was constructed using NEURON 7.2 simulation environment. The model is characterized by the presence of sodium channel, a non-inactivating potassium channel, Kv4.3 potassium channel, a low threshold T-type calcium channel and a hyperpolarization activated cation current. The model's input resistance and input capacitance were tuned to that of the experimental data [3, 4]. The model has an input capacitance value of 9.5 pF and an input resistance of 670-680 MΩ. We also compared the spike output of the model with that of the experimental data [6]. The model closely follows the experimental data for all values of injected current. We also tested the model for initial spike latency since stellate cells express members of Kv4 potassium channel family [5]. The model displayed a non-monotonic relationship between first spike delay and membrane potential with longer delays to first spike recorded for intermediate values of membrane potential similar to that of experimental data [6]. However, the model peak spike amplitude is too high, an area of future improvement.

This biophysical implementation of molecular layer interneuron will be used in a cerebellar cortex network model to investigate how their activity impacts target Purkinje neurons and how this is modified by gap junctions.

Authors’ Affiliations

(1)
Department of Theoretical Neurobiology and Neuroengineering, University of Antwerp, Wilrijk, 2610, Belgium
(2)
Okinawa Institute of Science and Technology, Okinawa, Japan

References

  1. Palay SL, Chan-Palay V: Cerebellar cortex: cytology and organization. 1974, Berlin, Heidelberg, New York: SpringerView ArticleGoogle Scholar
  2. Lise Korbo, Birgitte Bo Andersen, Ole Ladefoged, Arne Møller: Total numbers of various cell types in rat cerebellar cortex estimated using an unbiased stereological method. Brain Research. 1993, 609 (1-2): 262-268. 10.1016/0006-8993(93)90881-M. ISSN 0006-8993, 10.1016/0006-8993(93)90881-MView ArticleGoogle Scholar
  3. Hausser M, Clark BA: Tonic synaptic inhibition modulates neuronal output pattern and spatiotemporal synaptic integration. Neuron. 1997, 19: 665-678. 10.1016/S0896-6273(00)80379-7.View ArticlePubMedGoogle Scholar
  4. Southan AP, Robertson B: Electrophysiological characterization of voltage-gated K+ currents in cerebellar basket and Purkinje cells: Kv1 and Kv3 channel subfamilies are present in basket cell nerve terminals. J Neurosci. 2000, 20: 114-122.PubMedGoogle Scholar
  5. Hsu YH, Huang HY, Tsaur ML: Contrasting expression of Kv4.3, an A-type K+ channel, in migrating Purkinje cells and other post-migratory cerebellar neurons. Eur J Neurosci. 2003, 18: 601-612. 10.1046/j.1460-9568.2003.02786.x.View ArticlePubMedGoogle Scholar
  6. Molineux ML, Fernandez FR, Mehaffey WH, Turner RW: A-type and T-type currents interact to produce a novel spike latency-voltage relationship in cerebellar stellate cells. J Neurosci. 2005, 25: 10863-10873. 10.1523/JNEUROSCI.3436-05.2005.View ArticlePubMedGoogle Scholar

Copyright

© Sudhakar and De Schutter; licensee BioMed Central Ltd. 2013

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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