Neurons were previously infected with the Prox1::eGFP lentiviral vector. Whole-cell patch-clamp recordings were performed from Prox1::eGFP highlighted DG-like neurons after 3 weeks of differentiation. The bath was constantly perfused with an extracellular solution (128 mM NaCl, 5 mM KCl, 2 mM CaCl2, 30 mM glucose, 1 mM MgCl2 and 25 mM HEPES (pH 7.3)). The recording micropipettes (tip resistance 3–6 MΩ) were filled with internal solution (130 mM K-gluconate, 1 mM EGTA, 2 mM Mg-ATP, 0.3 mM Na-GTP, 5 mM Na-phosphocreatine and 10 mM HEPES (pH 7.3)). Recordings were made using Axopatch 200B or 700B amplifier (Axon Instruments). Signals were filtered at 2 kHz and sampled at 5 kHz. The series resistance was typically <15MΩ. For voltage-clamp recordings, the membrane potential was held at −70 mV. To record the sodium and potassium currents, cells were depolarized in 5 mV increments. For current-clamp recordings, a hyperpolarized current was injected into the neuron to a membrane potential of −55 mV or −45 mV, depending on the experiments. Step-depolarized currents with identical parameters were injected into normal and BD neurons to elicit APs. All recordings were performed at room temperature and chemicals were purchased from Sigma.
