Figure 7.

8-Br-cGMP differentially modulates spike-onset latencies between smaller and larger MNs in the dl-TMN. A, B, Membrane potential responses to hyperpolarizing current injections and those evoked by 100 Hz stimulation of presumed Ia afferents in smaller and larger MNs (A and B, respectively) obtained before (green traces) and during the application of 8-Br-cGMP (red traces). C, The relationship between the IRs and the latencies to first spikes obtained before and after the application of 8-Br-cGMP in four pairs of MNs of different sizes. The blue and red double-headed arrows represent the recruitment time, calculated as the difference in the mean latency to the first spike between the smaller and larger MNs obtained before and after the application of 8-Br-cGMP, respectively. *p < 0.05, Wilks’ lambda; ‡p < 0.05, paired t test.