Figure 6.

Interaction of optically stimulated nigral IPSPs with glutamatergic excitation. (A) Glutamate (0.5 mM) was “puffed” at the recorded neuron for 3 s (red line) with a patch pipette brought in close proximity. During the single spike mode triggered by glutamate excitation a 5 Hz train of 10 ms light pulses (indicated by blue bars) causes pauses in spiking but not LTS rebound burst is evoked. (B) Paired light pulses (2 ms pulse width, 20 ms interval) before glutamate excitation can cause LTS rebound bursts (as shown in Figure 5), but the same paired pulses during glutamate excitation result in spike pauses only. (C) A 20 Hz train of 5 ms light pulses results in a prolonged pause during glutamate excitation and a weak LTS rebound burst (2 spikes) afterwards.