Figure 6.

Effects of decreased synaptic transmission on episodic activity. A, Ventral root recordings from an E10 embryo cord. Control condition is in the presence of glutamate (Glu) and acetylcholine (ACh) receptor blockers. When bicuculline (2 μm) is added, the interepisode interval increases (in this case, by 22%), whereas duration shows no significant change. B, Interval and duration of episodes for pooled data, in the case of bicuculline (n = 11) or DHEAS (n = 8). Data are normalized with respect to control. All experiments were performed in the presence of glutamatergic and cholinergic blockers. Only interval is significantly different from control (^*p < 0.05; ^**p < 0.005). C, Time course of V and Cl_i from simulations (τ_d/τ_v = 4) for g_syn = 33 nS (corresponding to control) and g_syn = 27 nS (corresponding to bicuculline treatment). Interval in this case increases by 19%, and Cl_i range is shifted upward. D, Response diagram and trajectory on the V-Cl_i plane for g_syn = 33 and 27 nS; the Cl_i range over which bistability occurs is higher for lower g_syn.