Fig. s4

GABAergic agents did not elicit significant changes in the pattern of proliferation and apoptosis during development. The effect of either 1 M GABA, 1 M muscimol (GABAA agonist) or 100 M bicuculline (antagonist) on proliferation was assessed by phospho-histone 3 (Ser10) immunostaining on wholemount embryos at 24 hpf (upper row). However, there is no clear change in the pattern of proliferation at 24 hpf between control embryos and those treated with GABAergic agents. Besides, there are no differences in the number of mitotic nuclei among groups [% proliferating nuclei: control group = 25.14 ± 7.26 %, 1 M GABA = 23.68 ± 4.29; 1 M muscimol = 22.35 ± 3.37; 100 M bicuculline = 23.49 ± 0.52. No statistically significant changes, as determined by One-way analysis of variance]. TUNEL staining (lower row) was conducted to label apoptotic cells, and only a slight increase in peroxidase labelling was obtained in drug-treated groups. Images are from flatmount preparations, where embryos are oriented anterior towards the left and posterior towards the right. Scale bar: 200 m.