Figure 5. DISC1 regulates development of intrinsic excitability and formation of functional synapses of adult-born neurons.

(A, B) Firing of repetitive action potentials by GFP⁺ neurons at 2 wpi. Shown in (A) are sample traces recorded from a GFP⁺ neuron expressing shRNA-C1 or shRNA-D1 in response to 300 ms current injections (+100, 0, or −50 pA) under the whole-cell current-clamp before and after the addition of TTX (1 μM). Scale bars: 30 mV and 100 ms. Shown in (B) is the summary of the number of action potentials fired in response to current injections (100 pA, 300 ms). Values represent mean ± SEM (n = 9; *: p < 0.05, ANOVA). (C-F) GABAergic synaptic transmission recorded in GFP⁺ neurons at 2 wpi. Shown in (C) are sample traces of SSCs recorded in a GFP⁺ neuron expressing shRNA-C1 or shRNA-D1 under the whole-cell voltage-clamp (V_m = −65 mV) in the presence of TTX (1 μM) and kynurenic acid (5 mM). Shown are continuous recordings before and after the addition of bicuculline (10 μM). Scale bars: 20 pA and 100 ms. Also shown are the percentage of GFP⁺ neurons recorded that exhibited active GABAergic SSCs (D), mean frequency (E) and peak amplitude (F). Values represent mean ± SEM (*: p < 0.01; ANOVA). (G-J) Glutamatergic synaptic transmission recorded in GFP⁺ neurons at 2 wpi. Similar as in (C-F), except that the recordings were carried out in the presence of TTX (1 μM) and bicuculline (10 μM). Sample traces shown in (G) are continuous recordings before and after the addition of CNQX (50 μM).