Structural plasticity occurs physiologically or after brain damage to adapt or re-establish proper synaptic connections. This capacity depends on several intrinsic and extrinsic determinants that differ between neuron types. We reviewed the significant endogenous regenerative potential of the neurons of the inferior olive (IO) in the adult rodent brain and the structural remodeling of the terminal arbor of their axons, the climbing fiber (CF), under various experimental conditions, focusing on the growth-associated protein GAP-43. CFs undergo remarkable collateral sprouting in the presence of denervated Purkinje cells (PCs) that are available for new innervation. In addition, severed olivo-cerebellar axons regenerate across the white matter through a graft of embryonic Schwann cells. In contrast, CFs undergo a regressive modification when their target is deleted. In vivo knockdown of GAP-43 in olivary neurons, leads to the atrophy of their CFs and a reduction in the ability to sprout toward surrounding denervated PCs. These findings demonstrate that GAP-43 is essential for promoting denervation-induced sprouting and maintaining normal CF architecture.
Keywords: climbing fiber, GAP-43, sprouting, atrophy, branching
Citation: Grasselli G and Strata P (2013) Structural plasticity of climbing fibers and the growth-associated protein GAP-43. Front. Neural Circuits 7:25. doi: 10.3389/fncir.2013.00025
Received: 18 September 2012; Accepted: 03 February 2013;
Published online: 21 February 2013.
Edited by:Chris I. De Zeeuw, Erasmus MC, Netherlands
Reviewed by:David Linden, Johns Hopkins University, USA
Copyright © 2013 Grasselli and Strata. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and subject to any copyright notices concerning any third-party graphics etc.
*Correspondence: Giorgio Grasselli, Department of Neurobiology, University of Chicago, 947 E. 58th Street, MC0928, Chicago, IL 60637, USA. e-mail: firstname.lastname@example.org