Figure 3.

Mechanisms underlying the pause response evoked by thalamic activation. A, B, Samples traces of perforated patch-clamp recordings of two consecutive responses from ChIs before (control) and after treatment with the D2R antagonist sulpiride in hWT (A) and hMT1 (B) mice. In the presence of sulpiride (3 μm, 10 min) thalamic stimulation (50 Hz, 10 pulses) was unable to elicit the pause response in ChIs. C, In voltage-clamp recordings from hMT1 mice, thalamic stimulation (Th Stim) elicited an inward current in ChIs (HP −60 mV). Superimposed traces show the inward current before and during application of sulpiride (3 μm, 10 min), ω-conotoxin GVIA (ω-conotoxin, 1 μm, 10 min), and apamin (3 μm, 10 min) that suppressed the inward current evoked by thalamic activation. Similarly, intrapipette BAPTA (10 mm) was able to block the thalamically induced current. Results are summarized in the plot (C₁).