Dose–responses of intrathecal PKC inhibitors on pLTF. Each group received 12 μl intrathecal injections of PKC inhibitor of shown concentrations over the phrenic motor nucleus. A, Gö 6983 had no effect on pLTF at any dose. Amplitude of pLTF at 60 min after AIH in rats given injections of 0.1–2 mm Gö 6983 (n = 7) or 10 mm Gö 6983 (n = 2) compared with rats given vehicle (100% DMSO, n = 7) injections. B, NPC had no effect on pLTF at any dose. Amplitude of pLTF at 60 min after AIH in rats given injections of 100 μm NPC15437 (n = 2) or 5–40 mm NPC15437 (n = 7) compared with rats given vehicle (ACSF, n = 3) injections (p > 0.05). C, CID755673 had no effect on pLTF at any dose tested. Amplitude of pLTF at 60 min after AIH in rats given injections of 10 μm (n = 2), 50 μm (n = 2), or 0.2–5 mm CID755673 (n = 3) compared with rats given vehicle (10–20% DMSO in ACSF, n = 3) injections (p > 0.05). D, Sotrastaurin significantly attenuated pLTF. Amplitude of pLTF at 60 min after AIH in rats given injections of 0.2 μm (n = 2), 2 μm (n = 4), or 20 μm sotrastaurin (n = 2) compared with rats given vehicle (10% DMSO in ACSF, n = 2) injections. *Significant difference versus grouped time controls (rats given vehicle or drug with no AIH, n = 13). #Significant difference versus grouped vehicle AIH rats (0%–20% DMSO in ACSF, 100% DMSO with AIH, n = 20).