Choline acetyltransferase immunoreactivity in the developing brain of Xenopus laevis
Article first published online: 18 OCT 2002
Copyright © 2002 Wiley-Liss, Inc.
Journal of Comparative Neurology
Volume 453, Issue 4, pages 418–434, 25 November 2002
How to Cite
López, J. M., Smeets, W. J.A.J. and González, A. (2002), Choline acetyltransferase immunoreactivity in the developing brain of Xenopus laevis. J. Comp. Neurol., 453: 418–434. doi: 10.1002/cne.10419
- Issue published online: 18 OCT 2002
- Article first published online: 18 OCT 2002
- Manuscript Accepted: 26 JUL 2002
- Manuscript Revised: 9 JUL 2002
- Manuscript Received: 17 MAY 2002
- Spanish Ministry of Science and Technology. Grant Number: BOS2000-0559
The spatiotemporal sequence of the appearance of cholinergic structures in the brain of Xenopus laevis during development was studied by means of choline acetyltransferase (ChAT) immunohistochemistry. The first ChAT labeling in the central nervous system of Xenopus was obtained at late embryonic stages in the spinal motoneurons, the cranial nerve motor nuclei of the brainstem, and in amacrine cells of the retina. During premetamorphosis, these cholinergic structures maturated significantly and new ChAT-immunoreactive cells were observed in several other nuclei such as the solitary tract nucleus, isthmic nucleus, laterodorsal and pedunculopontine tegmental nuclei, epiphysis, dorsal habenular nucleus, medial amygdala, bed nucleus of the stria terminalis, and dorsal pallidum. Further maturation continued through prometamorphosis and the climax of the metamorphosis together with the appearance of new cell groups in the efferent octaval nucleus, ventral hypothalamic nucleus, anterior preoptic area, suprachiasmatic nucleus, and medial septum. Transient expression of ChAT was only seen in the large Mauthner cells that showed moderate ChAT labeling during pre- and prometamorphosis but became immunonegative at the end of the metamorphosis. The gradual appearance, in general from caudal to rostral brain levels, of ChAT immunoreactivity in Xenopus, was correlated with other developmental events to get insight into the possible roles of acetylcholine during ontogeny. Comparison with the developmental pattern of cholinergic systems in other vertebrates shows that Xenopus possesses abundant features in common with amniotes, suggesting a conservative developmental plan for tetrapods. J. Comp. Neurol. 453:418–434, 2002. © 2002 Wiley-Liss, Inc.