Figure 3.
Pharmacological profile of effects of TTX on NaP and NaT. A, Effect of 20 nm TTX on NaT from a representative nonburster neuron. Peak amplitude of NaT measured by voltage-clamp step (−70 to +10 mV; 10 ms duration) is only slightly affected by 20 nm TTX. NaT is completely blocked in this neuron by 1 μm TTX. B, Peak NaP and NaT amplitude versus TTX concentration, indicating relatively selective NaP attenuation at ≤20 nm TTX (n = 12; pooled intrinsic burster and nonburster pre-BötC neurons) with EC50 = 6.2 nm TTX concentration for NaP and 112 nm for NaT.