Fig. 9

Ascl1 in neurogenesis of GABAergic DA, NA and Sst1.1 dual transmitter neurons Ascl1a and Ascl1b mediate the transition from early (dlx2a+) to late (dlx5a+) GABAergic DA progenitors and the initiation of terminal differentiation. Terminal differentiation is then orchestrated by other transcription factors, for example by Arxa in the prethalamus and preoptic region and by Isl1 in the prethalamus. Ascl1a and Ascl1b are also crucial for the formation of sst1.1 expressing neurons, which are also GABAergic. NA neuron development is strongly dependent on Ascl1a and Ascl1b function. The upstream regulators of ascl1a and ascl1b in DA and NA neurogenesis remain to be identified. The arrows do not indicate exclusive regulation, but genetic interactions. Black gene names indicate pan-GABAergic DA regulators and red gene names prethalamus specific regulators. References: (1) Filippi et al. (2012); (2) Macdonald et al. (2013).