Subdivisions of the adult zebrafish subpallium by molecular marker analysis

Abstract

The morphology of the telencephalon displays great diversity among different vertebrate lineages. Particularly the everted telencephalon of ray-finned fishes shows a noticeably different morphology from the evaginated telencephalon of nonray-finned fishes and other vertebrates. This makes the comparison between the different parts of the telencephalon of ray-finned fishes and other vertebrates difficult. Based on neuroanatomical, neurochemical, and connectional data no consensus on the subdivisions of the adult telencephalon of ray-finned fishes and their relation to nuclei in the telencephalon of other vertebrates has been reached yet. For tetrapods, comparative expression pattern analysis of homologous developmental genes has been a successful approach to clarify homologies between different parts of the telencephalon. In the larval zebrafish, subdivisions of the subpallium have been proposed using conserved developmental gene expression. In this study, we investigate the subdivisions of the adult zebrafish telencephalon by analyzing the expression pattern of conserved molecular marker genes. We identify the boundary between the pallium and subpallium based on the complementary expression of dlx2a, dlx5a in the subpallium and tbr1, neurod in the pallium. Furthermore, combinatorial expression of Isl, nkx2.1b, lhx1b, tbr1, eomesa, emx1, emx2, and emx3 identifies striatal-like, pallidal-like, and septal-like subdivisions within the subpallium. In contrast to previous models, we propose that the striatum and pallidum are stretched along the rostrocaudal axis of the telencephalon. Further, the septal nuclei derive from both the pallium and subpallium. On this basis, we present a new model for the subdivisions of the subpallium in teleost fish.

Enhanced characterization of the zebrafish brain as revealed by super-resolution track-density imaging

“…For example, the clear visualization of the anterior commissure facilitated the demarcation of a border between the dorsal telencephalon and the ventral telencephalon (Fig. 5a), which corroborates previous immunohistochemical and molecular results (Mueller et al 2011;Ganz et al 2012). Similarly, some fiber tracks such as the lateral and medial forebrain bundles (LFB and MFB), which are very small in diameter (45µm) and therefore only appear as faint lines in the 10µm T 2 *-weighted image and as coarse red pixels in the 48µm DEC FA maps, could clearly be distinguished as discrete fiber bundles in the 5µm DEC stTDI maps.…”

Regeneration of the adult zebrafish brain from neurogenic radial glia-type progenitors

“…7A). To examine neuronal subtype and regional marker expression, we studied two neuronal subpopulations in our lineage-tracing experiments: (1) a neuronal subpopulation that expresses the transcription factor NeuroD1 and (2) a subpopulation of interneurons that co-expresses parvalbumin and Prox1 (supplementary material Figs S9, S13) (Ganz et al, 2011;Grandel et al, 2006). We find that recombined neurons express NeuroD1, parvalbumin and Prox1 correctly within the areas defined by these markers (Fig.…”

The Integration of Sociality, Monoamines, and Stress Neuroendocrinology in Fish Models: Applications in the Neurosciences

“…In relation to the aversive behaviour network, based on expression of ancillary markers, topology, and function, it has been proposed that the suppracommissural subpallium (Vs) is a partial homologue of the mammalian extended amygdala, including the striatal component and the bed nucleus of the stria terminalis, while the dorsomedial telencephalon (Dm) is homologous to the frontotemporal component of the amygdala (Maximino et al, 2013a). Finally, the shared structures (bed nucleus of the stria terminalis, lateral septum) are partially homologized to the Vs and ventral (Vv) and lateral (Vl) parts of the ventral telencephalon, respectively (Moreno et al, 2009;Ganz et al, 2012). These homologies and analogies are summarized in Table 1 and Figure 1B. …”