Central amygdala in anuran amphibians: Neurochemical organization and connectivity
Article first published online: 23 JUN 2005
Copyright © 2005 Wiley-Liss, Inc.
Journal of Comparative Neurology
Volume 489, Issue 1, pages 69–91, 15 August 2005
How to Cite
Moreno, N. and González, A. (2005), Central amygdala in anuran amphibians: Neurochemical organization and connectivity. J. Comp. Neurol., 489: 69–91. doi: 10.1002/cne.20611
- Issue published online: 23 JUN 2005
- Article first published online: 23 JUN 2005
- Manuscript Accepted: 14 MAR 2005
- Manuscript Revised: 4 FEB 2005
- Manuscript Received: 21 DEC 2004
- Spanish Ministry of Science and Technology. Grant Number: BFI2003-03756
- autonomic system;
- dextran amines;
The evolution of the amygdaloid complex in tetrapods is currently under debate on the basis of new neurochemical, hodological, and gene expression data. The anuran amygdaloid complex, in particular, is being examined in an effort to establish putative homologies with amniotes. The lateral and medial amygdala, comparable to their counterparts in amniotes, have recently been identified in anurans. In the present study we characterized the autonomic portion of the anuran amygdala, the central amygdala (CeA). First, the distribution of several neuronal markers (substance P, neuropeptide Y, somatostatin, tyrosine hydroxylase, and nitric oxide synthase) was analyzed. The localization of immunoreactive cells, primarily nitrergic cells, and the topographically arranged fiber labeling for all markers characteristically identified the CeA. Subsequently, the afferent and efferent connections of the CeA were investigated by means of in vivo and in vitro tracing techniques with dextran amines. The anuran CeA was revealed as the main component of the amygdaloid autonomic system, showing important connections with brainstem centers such as the parabrachial nucleus and the nucleus of the solitary tract. Only scarce CeA-hypothalamic projections were observed, whereas bidirectional connections between the CeA and the lateral and medial amygdala were abundant. The present neurochemical and hodological results support the homology of the anuran CeA with its counterpart in amniotes and strengthen the idea of a conserved amygdaloid organization in the evolution of tetrapods. J. Comp. Neurol. 489:69–91, 2005. © 2005 Wiley-Liss, Inc.