Synaptic Integration in Cerebellar Granule Cells

To understand the function of cerebellar granule cells, we need detailed knowledge about the information carried by their afferent mossy fibers and how this information is integrated by the granule cells. Recently, we made whole cell recordings from granule cells in the non-anesthetized, decerebrate cats. All recordings were made in the forelimb area of the C3 zone for which the afferent and efferent connections and functional organization have been investigated in detail. Major findings of the study were that the mossy fiber input to single granule cells was modality- and receptive field-specific and that simultaneous activity in two and usually more of the afferent mossy fibers were required to activate the granule cell spike. The high threshold for action potentials and the convergence of afferents with virtually identical information suggest that an important function of granule cells is to increase the signal-to-noise ratio of the mossy fiber–parallel fiber information. Thus a high-sensitivity, noisy mossy fiber input is transformed by the granule cell to a high-sensitivity, low-noise signal.

[1]  D. Marr A theory of cerebellar cortex , 1969, The Journal of physiology.

[2]  Henrik Jörntell,et al.  Properties of Somatosensory Synaptic Integration in Cerebellar Granule Cells In Vivo , 2006, The Journal of Neuroscience.

[3]  Henrik Jörntell,et al.  Reciprocal Bidirectional Plasticity of Parallel Fiber Receptive Fields in Cerebellar Purkinje Cells and Their Afferent Interneurons , 2002, Neuron.

[4]  M. Häusser,et al.  High-fidelity transmission of sensory information by single cerebellar mossy fibre boutons , 2007, Nature.

[5]  B. Barbour,et al.  Properties of Unitary Granule Cell→Purkinje Cell Synapses in Adult Rat Cerebellar Slices , 2002, The Journal of Neuroscience.

[6]  V. Braitenberg The cerebellar cortex as a timing organ: Discussion of an hypothesis , 1962 .

[7]  Masao Ito The Cerebellum And Neural Control , 1984 .

[8]  H. Jörntell,et al.  Parallel fibre receptive fields of Purkinje cells and interneurons are climbing fibre‐specific , 2001, The European journal of neuroscience.

[9]  C. Ekerot,et al.  Parallel fiber receptive fields: a key to understanding cerebellar operation and learning , 2008, The Cerebellum.

[10]  Henrik Jörntell,et al.  Cutaneous receptive fields and topography of mossy fibres and climbing fibres projecting to cat cerebellar C3 zone , 1998, The Journal of physiology.

[11]  J. Nadal,et al.  Optimal Information Storage and the Distribution of Synaptic Weights Perceptron versus Purkinje Cell , 2004, Neuron.