Fig. 5.

TEA inhibits the high-threshold current, whereas Cd²⁺ does not affect this current. Currents of acutely dissociated inferior colliculus neurons were recorded in response to voltage steps from −80 to +60 mV in 20 mV increments after a prepulse to −30 mV for 1 sec. An extracellular solution containing 2 mm TEA (A, B) or 0.5 mmCd²⁺ (D) was perfused into the recording dish, and cells were then washed with extracellular solution.A, Bath application of 2 mm TEA inhibited the high-threshold current. The inhibition was reversed by perfusing extracellular solution without TEA. The last three data points were measured in the presence of 1 μm TTX. B, Current traces before TEA (1), in the presence of 2 mm TEA (2), and after washing (3). The currents were leak-subtracted and filtered at 500 Hz. C, D, Current traces of an inferior colliculus neuron before (C) and during (D) application of 0.5 mmCd²⁺.