In the second experiment, we injected the GABAAR agonist pentobarbital (25 µg/g per day from 6 to 10 dpi, i.p.) to enhance synaptic GABA signaling in new neurons (Figure 2E). While there was little effect on shRNA-C1/GFP+ neurons, pentobarbital treatment further enhanced DISC1 knockdown-induced dendritic growth and pAKT and pS6 levels at 11 dpi (Figures 2E to 2H), again suggesting a synergistic interaction between DISC1 and GABA signaling. The effect of pentobarbital treatment is also specific for dendritic growth because other defects from DISC1 knockdown were not affected (Figures S2D to S2F).
