Figure 4

Capsaicin activates anterior cingulate cortex neurons. A. Current injection (220 pA, 800 ms) into a pyramidal neuron in layer II-III in the ACC induced action potential firing. Perfusion of capsaicin (50 μM) significantly increased the number of spikes. Note the slight depolarizing effect of capsaicin in the neuron (dashed line). The results indicate that TRPV1 receptors are functional in a cortical brain region involved in pain processing. B. Time course of capsaicin effect on the neuron shown in A