Response of chemosensitive neurons in the commissural NTS to epicardial application of capsaicin. A, original tracings showing the arterial pressure (AP), heart rate, and discharge of a NTS neuron in response to intra-arterial injection of potassium cyanide (KCN, 10 μg) and epicardial capsaicin (0.4 μg). B, bar graphs showing the mean data for discharge of chemosensitive NTS neurons before and after epicardial capsaicin (n=33) or normal saline (NS, n=6). *P<0.01 vs. before level.