Figure 6. The Stochastic Switch Model correctly predicts the sign and strength of synaptic connections.

(A) Synaptic weights (mean ± sem, n = 5 cohorts) from maximum likelihood fits to velocity data from wild type worms. (B, C) Left, synaptic current in AVB or AVA when the indicated presynaptic neuron was photoactivated (blue line). Right, mean synaptic current during the first 100 ms of the stimulus plotted against holding potential in the postsynaptic neuron (I-V curve). Lines show linear fits to the data at negative holding potentials which were used to estimate $v_{\text{Rev}}$. (D), Zero-current holding potential and reversal potential of synaptic currents (mean ± sem) in the indicated postsynaptic neuron (paired t-tests: AVA to AVB, p= 0.043, n = 9; AVB to AVA, p= 0.019, n = 17). (E), Scatter plot of synaptic currents recorded at a holding potential of -15 mV (unpaired t-test: p= 0.010, n ≥ 25).