Gene expression mapping of conserved GABAergic interneuron markers in developing zebrafish

γ-Aminobutyric acid (GABA)-expressing interneurons play a crucial role in regulating brain activity, and their impairment or loss is linked to various neurological disorders. While mammalian research establishes embryonic ganglionic eminences as the primary GABAergic source, the homologous spatiotemporal developmental pathways and marker profiles in zebrafish remain incompletely characterized. We identified a distinct subpallial region in the telencephalon at 1-2 days post-fertilization (dpf) co-expressing nkx2.1 and lhx6a, transcription factors characteristic of the medial ganglionic eminence (MGE). The caudal ganglionic eminence (CGE) transcription factor sp8 was expressed in the telencephalon, extending to mesencephalon and rhombencephalon, while prox1a expression localized to dorsal diencephalon, preoptic region, mesencephalon, and rhombencephalon. We also observed non-overlapping expression of canonical MGE interneuron markers sst1.1 (somatostatin) and pvalb6 (parvalbumin) within telencephalon, diencephalon, and mesencephalon at 3 and 5 dpf. Taken together, these results identify spatiotemporal expression patterns of conserved GE transcription factors and interneuron subtype markers within the developing zebrafish brain, providing an important foundation for using zebrafish models to investigate GABAergic interneuron development and disorders involving inhibitory dysfunction.