Original Research ARTICLE

Front. Neurosci., 15 October 2007 | http://dx.doi.org/10.3389/neuro.

Topography of the complete corticopontine projection: From experiments to principal maps

  • Centre for Molecular Biology and Neuroscience & Institute of Basic Medical Sciences, University of Oslo, Norway

The mammalian brain is characterized by orderly spatial distribution of its cellular components, commonly referred to as topographical organization. The topography of cortical and subcortical maps is thought to represent functional or computational properties. In the present investigation, we have studied map transformations and organizing principles in the projections from the cerebral cortex to the pontine nuclei, with emphasis on the mapping of the cortex as a whole onto the pontine nuclei. Following single or multiple axonal tracer injections into different cortical regions, three-dimensional (3-D) distributions of anterogradely labeled axons in the pontine nuclei were mapped. All 3-D reconstructed data sets were normalized to a standardized local coordinate system for the pontine nuclei and uploaded in a database application (FACCS, Functional Anatomy of the Cerebro-Cerebellar System, available via The Rodent Brain Workbench, http://www.rbwb.org ). The database application allowed flexible use of the data in novel combinations, and use of a previously published data sets. Visualization of different combinations of data was used to explore alternative principles of organization. As a result of these analyses, a principal map of the topography of corticopontine projections was developed. This map followed the organization of early spatiotemporal gradients present in the cerebral cortex and the pontine nuclei. With the principal map for corticopontine projections, a fairly accurate prediction of pontine target area can be made for any site of origin in the cerebral cortex. The map and the underlying shared data sets represent a basis for modeling of topographical organization and structure–function relationships in this system.

Keywords: 3-D reconstruction; axonal tracing; brain map; cerebellum; development; neuroinformatics; pontine nuclei

Citation: Trygve B. Leergaard and Jan G. Bjaalie (2007). Principal map of corticopontine projections. Front. Neurosci. 1:1. 211-223. doi: 10.3389/neuro.01/

Received: 15 August 2007; Paper pending published: 01 September 2007;
Accepted: 01 September 2007; Published online: 15 October 2007.

Edited by:

Idan Segev, Hebrew University, Israel

Reviewed by:

Philip H. Goodman, University of Nevada, USA
Mihail Bota, University of Southern California, USA
Idan Segev, Hebrew University, Israel

Copyright: © 2007 Leergaard and Bjaalie. This is an open-access article subject to an exclusive license agreement between the authors and the Frontiers Research Foundation, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are credited.

*Correspondence: Jan G. Bjaalie, Centre for Molecular Biology and Neuroscience & Institute of Basic Medical Sciences, University of Oslo, P.O. Box 1105 Blindern, N-0317 Oslo, Norway. e-mail: j.g.bjaalie@medisin.uio.no