Figure 8. The Ca²⁺-sensitive current is modulated by GTP-γ-S.

GTP-γ-S (500 μm) added to the intracellular solution in the recording pipette had a biphasic effect. It increased the Ca²⁺-sensitive current, which reached a peak about 6-7 min after the establishment of the whole-cell configuration. The Ca²⁺-sensitive current then showed rapid decay until it was almost completely abolished in all the neurons (B). The current traces shown in A relate to the labelled points in B. All the recordings were taken at −80 mV (Int 2 and Ext 4 in Table 1).