Figure 1. Normal development of electrical properties in cultured slices.

A, comparison of sodium current (I_Na), outward K⁺ current (I_K), the hyperpolarization-activated cation current (I_h), input resistance (R_in), and capacitance (C_M) values in neurones from acute E17 slices (black), acute P10 slices (grey), and slices cultured from E17 to P10 (white). For each parameter the values in acute P10 slices and the cultured E17–P10 slices were significantly different from the acute E17 slices, but were not significantly different from each other. Significance values for (E17 acute) versus (E17 cultured to P10) slices are shown on the plot; significance values for (P10 acute) versus (E17 cultured to P10) slices were all ≥ 0.15. B, voltage-clamp records for composite I_Na and I_K in the same three conditions as A. C, spontaneous synchronous [Ca²⁺]_i transients recorded from a cultured P0 slice in which 69 neurones were imaged for 46 min. Shown are data from 5 cells for 30 min of the recording. 61/69 neurons participated in this synchronous activity. D, time course of SSA in cultured slices. Frequency of synchronous events is shown as a function of developmental stage. SSA shows a strong peak at P0, as in acute slices. The E17 time point is from acute slices, since culture started at that stage in our experiments.