Abstract
The cerebellar cortical circuitry may support a distinct second form of associative learning, complementary to the well-known synaptic plasticity (long term depression, LTD) that has been previously shown. As the granule cell axons ascend to the molecular layer, they make multiple synapses on the overlying Purkinje cells (PC). This ascending branch (AB) input, which has been ignored in models of cerebellar learning, is likely to be functionally distinct from the parallel fiber (PF) synaptic input. We predict that AB-PF correlations lead to Hebbian-type learning at the PF-PC synapse, including long term potentiation (LTP), and allowing the cortical circuit to combine AB-PF LTP for feedforward state prediction with climbing fiber LTD for feedback error correction. The new learning mechanism could therefore add computational capacity to cerebellar models and may explain more of the experimental data.
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References
Albus, J. 1971. A theory of cerebellar function. Mathematical Biosci., 10:25–61.
Assad, C., Rasnow, B., and Stoddard, P.K. 1999. Electric organ discharges and electric images during electrolocation. J Experimental Biology, 202(10):1185–1193.
Assad, C., Hartmann, M.J., and Paulin, M.G. 2001. Reanimating Marr's bones: A new look at “A Theory of Cerebellar Cortex”. In Tenth Annual Computational Neuroscience Meeting, San Francisco and Pacific Grove, California, June 30-July 5, 2000 (abs).
Barto, A.G., Fagg, A.H., Sitkoff, N., and Houk, J.C. 1999. A cerebellar model of timing and prediction in the control of reaching. Neural Computation, 11:565–594.
Bastian, J. 1996. Plasticity in an electrosensory system. I. General features of a dynamic sensory filter. II. Postsynaptic events associated with a dynamic sensory filter. J. Neurophysiol., 76(4):2483–2507
Bell, C.C. 1993. The generation of expectations in the electrosensory lobe of mormyrid fish. J. Comp. Physiol. A, 173:677–680.
Bell, C.C., Cordo, P., and Harnad, S. (Eds.). 1996. Controversies in Neuroscience IV: Motor Learning and Synaptic Plasticity in the Cerebellum. Behav. Brain Sciences, 19(3).
Bell, C.C., Bodznick, D., Montgomery, J., and Bastian, J. 1997. The generation and subtraction of sensory expectations within cerebellum-like structures. Brain Behav. Evol., 50(suppl 1):17–31.
Bower, J.M. and Woolston, D. 1983. Congruence of spatial organization of tactile projections to granule cell and Purkinje cell layers of the cerebellar hemispheres of the albino rat: vertical organization of cerebellar cortex. J. Neurophys., 49(3):745–766.
Bullock, T.H. and Heiligenberg, W. (Eds.) 1986. Electroreception, Wiley: New York.
Coenen, O.J.M.D., Arnold, M.P., Sejnowski, T.J., and Jabri, M.A. 2001. Parallel fiber coding in the cerebellum for life-long learning. Autonomous Robots, 11(3):291–297.
Crepel, F. and Jaillard, D. 1991. Pairing of pre-and postsynaptic activities in cerebellar Purkinje cells induces long-term changes in synaptic efficacy in vitro. J. Physiol., 432:123–141.
Gundappa-Sulur, G. and Bower, J.M. 1990. Differences in ultramorphology and dendritic termination sites of synapses associated with the ascending and parallel fiber segments of granule cell axons in the cerebellar cortex of the albino rat. Society for Neuroscience Abstracts, 16:371.3.
Gundappa-Sulur, G., De Schutter, E., and Bower, J.M. 1999. Ascending granule cell axon: An important component of cerebellar cortical circuitry. J. Comp. Neurol., 408:580–596.
Ito, M. 1989. Long-term depression. Ann. Rev. Neurosci., 12:85–102.
Kanerva, P. 1988. Sparse Distributed Memory, MIT Press: Boston, MA.
Keeler, J.D. 1990. A dynamical system view of cerebellar function. Physica D, 42:396–410.
Llinas, R. 1982. Radial connectivity in the cerebellar cortex: A novel view regarding the functional organization of the molecular layer. In The Cerebellum, New Vistas, Springer-Verlag: New York.
Marr, D. 1969. A theory of cerebellar cortex. J. Physiol., 202:437–470.
Miall, R.C. and Wolpert, D.M. 1996. Forward models for physiological motor control. Neural Networks, 9:1265–1279.
Palay, S.L. and Chan-Palay, V. 1974. Cerebellar Cortex: Cytology and Organization, Springer-Verlag: New York.
Paulin, M.G. 1993. The role of the cerebellum in motor control and perception. Brain Behav. Evol., 41:39–50.
Schweighofer, N., Spoelstra, J., Arbib, M.A., and Kawato, M. 1998. Role of the cerebellum in reaching movements in humans. II. A neural model of the intermediate cerebellum. Eur. J. Neuroscience, 10:95–105.
Wickelgren, I. 1998. The cerebellum: The brain's engine of agility. Science, 281:1588–1590.
Wolpert, D.M., Miall, R.C., and Kawato, M. 1998. Internal models in the cerebellum Trends Cognit., 2:338–347.
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Assad, C. An Hypothesis for a Novel Learning Mechanism in the Cerebellar Cortex. Autonomous Robots 11, 285–290 (2001). https://doi.org/10.1023/A:1012451326151
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DOI: https://doi.org/10.1023/A:1012451326151