Figure 5.

Whole-cell voltage-clamp sIPSC recordings from TMN neurons in rat thin slices. A, TMN neuron approached with a patch pipette (scale bar, 20 μm) and identified with the stimulation protocol shown at right. Hyperpolarization-activated inward current (I_h) becomes obvious after voltage jumps from −50 to −90 mV and to more negative values. Maximal outward I_A current is seen after return to the holding membrane potential from −120 mV. B, TRH (2.5 μm)-induced depression of sIPSC frequency (at room temperature). The GABA_A receptor antagonist gabazine (10 μm) blocks spontaneous synaptic activity. C, AMPA and NMDA receptor antagonists (DNQX and d-AP5, respectively) reduce frequency of sIPSCs without affecting their kinetics or amplitude.