Figure 2.

BQA modeling of evoked responses from paired recordings could be used to estimate the quantal parameters from synaptic responses recorded under different conditions of release probability. Renshaw cell responses are shown alongside their respective amplitude distributions observed during applications of extracellular calcium concentrations of 1 mm (A) and 2 mm (B). Black lines indicate the amplitude distribution calculated from the BQA estimates of quantal parameters. The current artifacts recorded from the Renshaw cell electrode result from coupling between the amplifiers during the current step-induced spikes in the motoneuron and therefore precede postsynaptic responses. BQA yields probability distributions for the quantal size (C; q) and maximal response (D; r where r = nq and n is the number of release sites). E, The projected probability distribution for the number (n) of release sites.