Table 1.

Effect of nominally zero Ca²⁺ and TRPV1 antagonists on caffeine-evoked Ca²⁺ transients recorded in isolated nodose ganglion neurons

Control	IRTX	Zero Ca2+ Locke	Zero Ca2+ Locke + IRTX	n
304 ± 32	–	122 ± 29		6
405 ± 114	205 ± 53	220 ± 55		9
398 ± 73	–	244 ± 53	231 ± 53	5
Control	BCTC	Zero Ca2+ Locke	Zero Ca2+ Locke + BCTC	n
572 ± 73	395 ± 64	382 ± 59		8
395 ± 33	–	253 ± 25	245 ± 35	7

Each row represents a separate experimental series. TRPV1 antagonists, IRTX and BCTC, were used at 100 and 175 nM, respectively. Caffeine (10 mM) was applied for 15 s to evoke caffeine-induced Ca²⁺ transients (CICTs) measured with fura-2. Caffeine was applied at 1.5–3 min intervals. Drug or nominally zero Ca²⁺ Locke solution preceded the caffeine pulses by 0.5 and 2 min, respectively (see Figs. 1 and 2). The values are in nM. Zero Ca²⁺ significantly reduced the amplitude of CICT, row 1. The amplitude of the CICT in the presence of IRTX was not significantly different from that recorded in zero Ca²⁺ and both treatments were significantly different from control values, row 2. Addition of IRTX to zero Ca²⁺ Locke solution did not significantly change the amplitude of CICT. The amplitude of CICT recorded in zero Ca²⁺ Locke or IRTX plus zero Ca²⁺ Locke solution was significantly different from control values, row 3. BCTC significantly reduced the amplitude of CICT and its effect was not significantly different from that measured in zero Ca²⁺ Locke solution, row 4. The amplitude of the CICT in the presence of BTCT was not significantly different from that recorded in zero Ca²⁺ Locke solution, but both treatments were significantly different from control values, row 4. Addition of BCTC to zero Ca²⁺ Locke solution did not significantly reduce the amplitude of the CICTs, row 5. Statistical significance was assessed with an one-way ANOVA performed with Student–Newman–Keuls post hoc test to determine significance for pair-wise comparisons. P < 0.05 indicated statistical significance. Data in row 1 were compared with a paired Student t test; n represents the number of nodose ganglion cells studied in each row