Fig. 12.
Blocking ILV made the spike trains of transient neurons more regular. A, top: an irregular spike train (CV 0.8, mean interval 73 ms) from a P11 transient neuron, driven by pseudo-EPSCs with a unitary amplitude of 340 pA. Bottom: coapplication of α-DTX and linopirdine made spikes faster and more regular. (Spike rate increased in the blocker solution, so we reduced unitary amplitude to 170 pA, for a mean interval of 53 ms.) B–D: CV values as functions of mean interval are shown for 4 transient neurons before (black symbols) and after (gray symbols) ILV block: lines, average CV-interval curves (Fig. 11) for transient (thick black line) and sustained (thin gray line) neurons. Perforated-patch recordings. Data in B are from the neuron in A. E: patch rupture made a neuron more regular. Transient neuron, recorded in perforated-patch mode in control solution (black symbols; CV 0.6–0.8) and 100 μM α-DTX (black and gray symbols), which reduced CV to 0.3–0.5. The patch then ruptured and the neuron became extremely regular (gray symbols; CV 0.1–0.2).