title: 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.
authors.affiliation: Department of Human Anatomy, Faculty of Medicine, University of Murcia, 30100 Murcia, Spain.
authors.forename: Margarita
authors.initials: M
authors.lastname: García-López
authors.forename: Antonio
authors.initials: A
authors.lastname: Abellán
authors.forename: Isabel
authors.initials: I
authors.lastname: Legaz
authors.forename: John L R
authors.initials: JL
authors.lastname: Rubenstein
authors.forename: Luis
authors.initials: L
authors.lastname: Puelles
authors.forename: Loreta
authors.initials: L
authors.lastname: Medina
mesh_terms: D000679:Amygdala / Q000166:cytology* / Q000196:embryology*; D000818:Animals; D020392:Entopeduncular Nucleus / Q000166:cytology / Q000196:embryology; D005260:Female; D018507:Gene Expression Regulation, Developmental; D053823:Hedgehog Proteins / Q000235:genetics; D018398:Homeodomain Proteins / Q000235:genetics; D060850:LIM-Homeodomain Proteins; D051379:Mice / Q000502:physiology*; D009419:Nerve Tissue Proteins / Q000235:genetics; D009687:Nuclear Proteins / Q000235:genetics; D011247:Pregnancy; D011301:Preoptic Area / Q000166:cytology / Q000196:embryology; D012686:Septal Nuclei / Q000166:cytology / Q000196:embryology; D020665:Septum of Brain / Q000166:cytology / Q000196:embryology; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors / Q000235:genetics*
chemical_list: C501120:Dlx5 protein, mouse; C490147:Gbx1 protein, mouse; D053823:Hedgehog Proteins; D018398:Homeodomain Proteins; C498504:LHX6 protein, mouse; C112960:LIM homeobox protein 8; D060850:LIM-Homeodomain Proteins; C117058:Lhx9 protein, mouse; D009419:Nerve Tissue Proteins; C000614414:Nkx2-1 protein, mouse; D009687:Nuclear Proteins; C465570:Shh protein, mouse; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors