FIGURE 4.

The β4-containing nAChRs include α3 or α6 subunits. This experiment was conducted with rat DRG neurons in the presence of a cocktail of VGCC blockers, as described in the Figure 2 legend. PNU-120596 (1 μM) was applied after the second ACh pulse, revealing the α7-expressing subclass. ACh responses from the α7-expressing subclass were blocked reversibly by 200 nM ArIB[V11L;V16D] (bottom three traces), which did not block the neuronal subclass that expresses primarily β4-containing nAChRs. ACh responses from the β4-expressing nAChRs were blocked reversibly by 50 μM AuIB (second through fourth traces from the top), suggesting that the β4-expressing nAChRs also contain α3 or α6 subunits (see Table 1). Short, black horizontal bars indicate when the different conotoxins were present in the bath. The top trace illustrates a response from an additional neuronal subclass that expresses both α7 nAChRs and β4-containing nAChRs.