Figure 3.

Ca²⁺ current recordings showing cells with N- and P/Q, only N-type, and only P/Q-type channels. (A) Using a depolarizing step at −50 mV, Ca²⁺ currents were recorded in the presence of SB+TTX+TEA-Cl from a cell with both N and P/Q- type channels (left panel) before (black record), after ω-CgTx (blue record, reduction) and ω-CgTx (red record, reduction). (B) Ca²⁺ currents recorded from a cell with only N-type channels (middle panel) before (black record), after ω-Aga (blue record, no effect) and ω-CgTx (red record, reduction). (C) Ca²⁺ currents were recorded from a cell with only P/Q- type channels (right panel) before (black record), after ω-CgTx (red record, no effect), and ω-Aga (red record, reduction). (D) Representative currents obtained using a depolarization protocol with multiple steps (see Methods), showing only the 0 mV step. Initial currents were recorded in the presence SB+TTX+TEA-Cl (left record). ω-Aga was superfused in the aCSF bath for 10 min causing a reduction in the current (second record). ω-CgTx (third record) was then superfused for 10 min causing a further reduction in the current, followed by the addition of Cadmium (right record) for 10 min leading to a complete block of the Ca²⁺ currents.