Adducin phosphorylation in pleural ganglia is increased 18 hr after initial LTF induction. Pleural–pedal ganglia were desheathed and continously perfused with ASW. One pleural–pedal complex from each animal served as a control and was perfused with ASW only. The pleural–pedal complex from the opposite body side received five spaced 5 min pulses of 5-HT (50 μm in ASW; 10 min between pulses) to induce LTF. Pleural and pedal ganglia were homogenized separately in SDS sample buffer 1 or 18 hr after 5-HT treatment. Sample processing was as described previously for Figure3B. A, Coomassie-stained gels and Western blots from samples taken 18 hr after 5-HT treatment (+) or control perfusion (−). B, ApADD and phospho-ApADD levels in samples were quantified densitometrically from Western blot autoradiographs. For each sample, phospho-ApADD levels were normalized to total ApADD levels. Numbers in the histograms indicate the number of samples in each group. Means were calculated for each treatment and control groups. The means for the control groups (unstimulated ganglia) were set to 1. Asterisks indicate means that are significantly different from the mean of the corresponding control group (p < 0.05).