This article is linked to a neuroinformatics Web archive available at http://www.nesys.uio.no/. The archive contains (1) superimposed multilabeling microscope images, (2) atlas-style illustrations for all experimental animals, (3) videos of three-dimensional distribution patterns and overlap analysis, and (4) original coordinate files for downloading and free reuse by other investigators. For other related papers, see www.nesys.uio.no/Database.
Three-dimensional topography of corticopontine projections from rat sensorimotor cortex: Comparisons with corticostriatal projections reveal diverse integrative organization†
Article first published online: 14 SEP 2004
Copyright © 2004 Wiley-Liss, Inc.
Journal of Comparative Neurology
Volume 478, Issue 3, pages 306–322, 18 October 2004
How to Cite
Leergaard, T. B., Alloway, K. D., Pham, T. A.T., Bolstad, I., Hoffer, Z. S., Pettersen, C. and Bjaalie, J. G. (2004), Three-dimensional topography of corticopontine projections from rat sensorimotor cortex: Comparisons with corticostriatal projections reveal diverse integrative organization. J. Comp. Neurol., 478: 306–322. doi: 10.1002/cne.20289
- Issue published online: 14 SEP 2004
- Article first published online: 14 SEP 2004
- Manuscript Accepted: 5 JUL 2004
- Manuscript Revised: 1 JUL 2004
- Manuscript Received: 16 APR 2004
- The Research Council of Norway
- European Community Grant. Grant Number: QLRT-2000-02256
- National Institutes of Health Grant. Grant Number: NS-37532
- somatosensory cortex;
- motor cortex;
- pontine nuclei;
- basal ganglia;
- 3-D reconstruction
The major cortical–subcortical re-entrant pathways through the basal ganglia and cerebellum are considered to represent anatomically segregated channels for information originating in different cortical areas. A capacity for integrating unique combinations of cortical inputs has been well documented in the basal ganglia circuits but is largely undefined in the precerebellar circuits. To compare and quantify the amount of overlap that occurs in the first link of the cortico–ponto–cerebellar pathway, a dual tracing approach was used to map the spatial relationship between projections originating from the primary somatosensory cortex (SI), the secondary somatosensory cortex (SII), and the primary motor cortex (MI). The anterograde tracers biotinylated dextran amine and Fluoro-Ruby were injected into homologous whisker representations of either SI and SII, or SI and MI. The ensuing pontine labeling patterns were analyzed using a computerized three-dimensional reconstruction approach. The results demonstrate that whisker-related projections from SI and MI are largely segregated. At some locations, the two projections are adjoining and partly overlapping. Furthermore, SI contributes significantly more corticopontine projections than MI. By comparison, projections from corresponding representations in SI and SII terminate in similar parts of the pontine nuclei and display considerable amounts of spatial overlap. Finally, comparison of corticopontine and corticostriatal projections in the same experimental animals reveals that SI–SII overlap is significantly larger in the pontine nuclei than in the neostriatum. These structural differences indicate a larger capacity for integration of information within the same sensory modality in the pontocerebellar system compared to the basal ganglia. J. Comp. Neurol. 478:306–322, 2004. © 2004 Wiley-Liss, Inc.