Article

Identification of distinct telencephalic progenitor pools for neuronal diversity in the amygdala

Center for Neuroscience Research, Children's National Medical Center, 111 Michigan Avenue, NW, Suite 645, Washington, DC 20010, USA.
Nature Neuroscience (Impact Factor: 16.1). 02/2009; 12(2):141-9. DOI: 10.1038/nn.2241
Source: PubMed

ABSTRACT

The development of the amygdala, a central structure of the limbic system, remains poorly understood. We found that two spatially distinct and early-specified telencephalic progenitor pools marked by the homeodomain transcription factor Dbx1 are major sources of neuronal cell diversity in the mature mouse amygdala. We found that Dbx1-positive cells of the ventral pallium generate the excitatory neurons of the basolateral complex and cortical amygdala nuclei. Moreover, Dbx1-derived cells comprise a previously unknown migratory stream that emanates from the preoptic area (POA), a ventral telencephalic domain adjacent to the diencephalic border. The Dbx1-positive, POA-derived population migrated specifically to the amygdala and, as defined by both immunochemical and electrophysiological criteria, generated a unique subclass of inhibitory neurons in the medial amygdala nucleus. Thus, this POA-derived population represents a previously unknown progenitor pool dedicated to the limbic system.

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    • "The VPall migratory stream and associated glial bundle (Medina et al., 2004 ) is strictly eschewed by all claustral and migrated dorsal endopiriform Nr4a2-positive cells developing initially within the LPall. We already know that the VPall stream does not practically contribute neurons to either the claustrum or the insula, as demonstrated by Dbx1-derived progeny (Figure 4.10C; Bielle et al., 2005; Hirata et al., 2002 Hirata et al., , 2009 Teissier et al., 2010). There are nevertheless ventropallial Dbx1-derived Cajal-Retzius neurons that pass subpially across LPall into the DPall (Figure 4.16; Bielle et al., 2005), some of which probably remain in the layer 1 of the insula. "
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    • "We used mice that express Cre recombinase fused to the tamoxifen-sensitive estrogen receptor (CreER T2 ) in cells expressing Dbx1, that is, Dbx1 CreERT2 (Hirata et al. 2009). Dbx1 CreERT2 mice were mated with floxed reporter mice in which the Rosa26 locus was modified by targeted insertion of a loxP-flanked STOP cassette followed by tandem dimer (td) Tomato (Rosa26 tdTomato , strain name: B6;129S6-Gt(ROSA)26Sor tm9(CAG-tdTomato)Hze /J, Jax No. 007905; Madisen et al. 2010). "
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    • "The migratory cells of the lateral cortical stream (LCS) are derived from progenitors in the VZ of the PSPB and migrate ventrally towards the amygdaloid region where they contribute to the developing amygdala [47,50,59,60]. The LCS contains cells derived from both the pallium (Pax6+ and Tbr1+) and the subpallium (Dlx2+ and Gsh2+) [47,50,59]. "
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