FIGURE 5.

Adenosine inhibits calcium currents in mitral cells. (A) Calcium currents were isolated by suppressing sodium currents with TTX (0.5 μM) and potassium currents by replacing K⁺ with Cs⁺ and including TEA (20 mM) and 4-AP (5 mM) in the pipette solution. Calcium currents were entirely blocked by Ni²⁺ (200 μM) and Cd²⁺ (200 μM). Subtraction of currents in presence of Ni²⁺/Cd²⁺ from control currents revealed the Ni²⁺/Cd²⁺-sensitive currents (Ctrl-Ni²⁺/Cd²⁺, right traces). (B) Current-voltage (IV) relationship of calcium currents in the absence (Ctrl) and presence of Ni²⁺ and Cd²⁺ (green graph). Ctrl - Ni²⁺/Cd²⁺ represents the current that was blocked by Ni²⁺/Cd²⁺. (C) Calcium currents were reduced by adenosine (100 μM). Ctrl - Ado represents the current that was blocked by adenosine. (D) IV relationship of the adenosine-sensitive calcium current (blue graph).