Fig. 3.

Elevation of postsynaptic intracellular Ca²⁺ is sufficient to trigger LTD. A, A single example of a neuron recorded from for 40 min while collecting baseline EPSCs. At the arrow, synaptic stimulation was stopped, and the neuron was repetitively stepped 20 times to +10 mV for 3 sec, once every 5 sec. Synaptic stimulation was then resumed at 0.1 Hz. This protocol was sufficient to induce LTD. Inset,The averages of five EPSCs taken at the times indicated on the graph. Calibration: 200 pA, 10 msec. B, The average of 12 such experiments. All experiments in this figure were performed in ACSF containing 5 mm Ca²⁺. LTD elicited by repetitive depolarization is 79 ± 7% of control values (n = 11, 6 identified dopamine neurons).