Immunohistochemical localization of calbindin-D28k and calretinin in the spinal cord of Xenopus laevis
Article first published online: 22 DEC 2005
Copyright © 2005 Wiley-Liss, Inc.
Journal of Comparative Neurology
Volume 494, Issue 5, pages 763–783, 10 February 2006
How to Cite
Morona, R., Moreno, N., López, J. M. and González, A. (2006), Immunohistochemical localization of calbindin-D28k and calretinin in the spinal cord of Xenopus laevis. J. Comp. Neurol., 494: 763–783. doi: 10.1002/cne.20836
- Issue published online: 22 DEC 2005
- Article first published online: 22 DEC 2005
- Manuscript Accepted: 6 SEP 2005
- Manuscript Revised: 12 AUG 2005
- Manuscript Received: 22 JUN 2005
- Spanish Ministry of Science and Technology. Grant Number: BFI2003-03756
- calcium binding proteins;
- dextran amines;
Immunohistochemical techniques were used to investigate the distribution and morphology of neurons containing the calcium-binding proteins calbindin-D28k (CB) and calretinin (CR) in the spinal cord of Xenopus laevis and determine the extent to which this organization is comparable to that of mammals. Most CB- and CR-containing neurons were located in the superficial dorsal gray field, but with distinct topography. The lateral, ventrolateral, and ventromedial fields also possessed abundant neurons labeled for either CB or CR. Double immunohistofluorescence demonstrated that a subpopulation of dorsal root ganglion cells and neurons in the dorsal and ventrolateral fields contained CB and CR. By means of a similar technique, a cell population in the dorsal field was doubly labeled only for CB and nitric oxide synthase (NOS), whereas in the ventrolateral field colocalization of NOS with CB and CR was found. Choline acetyltransferase immunohistochemistry revealed that a subpopulation of ventral horn neurons, including motoneurons, colocalized CB and CR. The involvement of CB- and CR-containing neurons in ascending spinal projections was demonstrated combining the retrograde transport of dextran amines and immunohistochemistry. Cells colocalizing the tracer and CB or CR were quite numerous, primarily in the dorsal and ventrolateral fields. Similar experiments demonstrated supraspinal projections from CB- and CR-containing cells in the brainstem and diencephalon. The distribution, projections, and colocalization with neurotransmitters of the neuronal systems containing CB and CR in Xenopus suggest that CB and CR are important neuromodulator substances with functions conserved in the spinal cord from amphibians through mammals. J. Comp. Neurol. 494:763–783, 2006. © 2005 Wiley-Liss, Inc.