Figure 2.

Post-stimulus histogram of neuron firing linked to electrical SSS stimulation. Recordings were made from neurons in the trigeminal nucleus caudalis using tungsten-in-glass electrodes surrounded by microiontophoretic pipette barrels. The superior sagittal sinus was electrically stimulated with 250 μs pulses of 120–150 V at 0.3–0.5 Hz using a bipolar platinum wire hook electrode. Typically resistances along the sinus between the two poles of the stimulating electrode were around 2.0 MΩ giving a suprathreshold stimulus current of 60–75 μA. The histogram shows the results from 100 such stimuli.