Histogenetic compartments of the mouse centromedial and extended amygdala based on gene expression patterns during development

Abstract

The amygdala controls emotional and social behavior and regulates instinctive reflexes such as defense and reproduction by way of descending projections to the hypothalamus and brainstem. The descending amygdalar projections are suggested to show a cortico-striato-pallidal organization similar to that of the basal ganglia (Swanson [2000] Brain Res 886:113-164). To test this model we investigated the embryological origin and molecular properties of the mouse centromedial and extended amygdalar subdivisions, which constitute major sources of descending projections. We analyzed the distribution of key regulatory genes that show restricted expression patterns within the subpallium (Dlx5, Nkx2.1, Lhx6, Lhx7/8, Lhx9, Shh, and Gbx1), as well as genes considered markers for specific subpallial neuronal subpopulations. Our results indicate that most of the centromedial and extended amygdala is formed by cells derived from multiple subpallial subdivisions. Contrary to a previous suggestion, only the central--but not the medial--amygdala derives from the lateral ganglionic eminence and has striatal-like features. The medial amygdala and a large part of the extended amygdala (including the bed nucleus of the stria terminalis) consist of subdivisions or cell groups that derive from subpallial, pallial (ventral pallium), or extratelencephalic progenitor domains. The subpallial part includes derivatives from the medial ganglionic eminence, the anterior peduncular area, and possibly a novel subdivision, called here commissural preoptic area, located at the base of the septum and related to the anterior commissure. Our study provides a molecular and morphological foundation for understanding the complex embryonic origins and adult organization of the centromedial and extended amygdala.

Ethanol–BDNF interactions: Still more questions than answers

“…The identity of the cells expressing BDNF is also of interest. The striatum and CeA, but not the MeA, share a common embryonic origin in the lateral ganglionic eminence (García-López et al, 2008). The majority of the cells in the CeA are of the medium spiny type and presumably GABAergic (McDonald, 1982).…”

Global view of the functional molecular organization of the avian cerebrum: mirror images and functional columns

“…We chose the zebra finch as our focal species because of its wide use in neuroscience (Zeigler and Marler, 2004). We chose the specific genes based on their distinct expression patterns in the telencephalon, their diverse molecular functions (glutamate receptors, FOXP2), and their use to distinguish cell types in the mammalian brain, including dopamine receptors in striatal neurons, ROR-β in layer IV cortex neurons, ER81 in layer V cortex and amygdala neurons, and LHX9 in amygdala neurons (Molnar and Cheung, 2006;Watakabe et al, 2007;Garcia-Lopez et al, 2008). We chose the specific brain regions to test the relationships proposed in the 2004-2005 brain nomenclature (Reiner et al, 2004a;Jarvis et al, 2005) and to resolve alternative views on which brain regions constitute the newly defined hyperpallium, mesopallium, and arcopallium Feenders et al, 2008;Puelles et al, 2008).…”

Expression analysis of Sulf1 in the chick forebrain at early and late stages of development

“…Rostrally, in the secondary prosencephalon, the expression pattern was distributed in alar and basal neuroepithelial domains, while in the diencephalon Sulf1 expression was restricted to the basal plate epithelium. Although Sulf1 expression in the basal plate, telencephalic POA and SPa could be directly related to the regulation of Shh signaling due to the expression of both genes in nearby domains Bardet, 2007;García-López et al, 2008), Sulf1 expression throughout the choroids plexus (chp) seems to be unrelated to Shh signaling.…”