Fig. 2

Morphological and electrophysiological differences among green fluorescent protein (GFP)-positive cells (GFP(+)), GFP-negative cells located in medial DRN (mGFP(−)), and GFP-negative cells located in lateral DRN (lGFP(−)). a Immunohistochemistry of the 3 types of DRN cells. The cell is double-labeled for both tryptophan hydroxylase (TPH; green) and biocytin (red). Scale bar 10 μm in both panels. b Representative action potential (AP) waveforms of GFP(+), mGFP(−), and lGFP(−) neurons. These APs were elicited by the minimum depolarizing holding current. c AP waveforms of GFP(+), mGFP(−), and lGFP(−) neurons in the DRN that were generated by injecting currents of 100 pA (black), 200 pA (green), and 400 pA (orange), respectively. d Input–output relationship curves of GFP(+), mGFP(−), and lGFP(−) neurons in the DRN (GFP(+), n = 39; mGFP(−), n = 35; lGFP(−), n = 18). APs were generated by injecting current steps from 0 to 400 pA in increments of 20 pA. The firing frequency of AP were calculated at the period of current injection (400 ms)