Figure 9

A PKC family kinase mediates arachidonic acid-dependent regulation of presynaptic neuropeptide release competency. (A). Recordings of VD4-RPeD1 soma-soma paired neurons cultured in DM + vehicle control (i; 0.1% DMSO), or DM + 1 μM Chelerythrine Chloride (ii; Ch Cl⁻, PKC inhibitor). Recordings were made in the presence of AChR antagonists (5 μM MLA, 10 μM TC, 20 μM TEA) to isolate peptidergic transmission. Antagonism of PKC inhibits neuropeptide release, indicating that it perturbs retrograde AA signaling interactions between VD4-RPeD1. (B). Summary data, mean peptidergic synaptic response in RPeD1 measured in the presence of AChR antagonists. N ≥ 8. **P = 0.007 (Mann–Whitney U test). (C). Recordings of peptidergic transmission between VD4-VF neurons, as in (A). VD4-VF neurons were cultured in DM + vehicle control (i; 0.1% DMSO + 0.1% Tocrisolve; data in part is repeated here from Fig. 8A), DM + 1 μM Ch Cl⁻ (ii), DM + 5 μM AA (iii; data is repeated here from Fig. 8A), or DM + 5 μM AA + 1 μM Ch Cl⁻ (iv). Antagonism of PKC inhibits the induction of neuropeptide release by AA, but otherwise has no effect on peptidergic transmission between VD4-VF. (D). Summary data, mean peptidergic synaptic response in VF, as in (B). N ≥ 10. **P ≤ 0.002, ***P < 0.001 (Independent Samples Kruskal–Wallis test). Error bars, SEM.