Figure 1.

Synaptic transmission block by preterminal microinjection of BoNT/C1-LC. (A) Blocking of transmitter release as determined by the reduction of the postsynaptic activation (post) with time reported in minutes after injection (numbers to the right starting with the control level, ctl). The presynaptic action potential (pre) was unchanged by the injection. (B) Presynaptic voltage-clamp step (middle trace), presynaptic calcium current (bottom trace), and simultaneously recorded postsynaptic response (top traces) at different times after presynaptic BoNT/C1-LC microinjection. Time, in minutes, after microinjection is on the right (ctl). Note the lack of change in the calcium current.