Electrophysiological properties of GAD67+ and VGLUT+ neurons. A1-F1: GAD67+ neuron presents electrophysiological properties of fast-firing neuron. A2-F2: VGLUT+ neuron presents electrophysiological properties of cluster-firing neuron. A1-2: Agarose gel analysis of the sc-RT-PCR products to identify chemical phenotypes of recorded neurons. B1 and C1: Membrane responses of the same MS/DBB neuron to injection of depolarizing current pulses applied from a membrane potential of -60 mV (B1) or -80 mV (C1). GAD67+ neuron displays fast-firing activity. B2 and C2: Membrane responses of the VGLUT+ neuron to injection of depolarizing current pulses (0.2 nA) applied from a membrane potential of -60 mV, prolonged depolarization current (4s in duration) elicits cluster-firing separated by subthreshold membrane oscillations (C2). D1-2: In current-clamp mode, the response to injections of hyperpolarizing current pulse from -60 mV, note profound depolarizing sag in GAD67+ neuron, but no rebound firing action potential (D1). E1-2: Currents recorded in voltage-clamp mode evoked by a series of hyperpolarizing voltage steps applied from a holding potential of -50 mV. Notice the profound depolarizing amplitude inward current in GAD67+ neuron, as shown by the differences between the amplitudes of the instantaneous current (filled circle) and steady-state current (open circle). F1-2: Instantaneous and steady-state I-V plots derived from the data in E1-2.