In the leech, serotonin (5HT) is involved through the activation of cAMP dependent protein kinases in short-term non associative learning (sensitization and dishabituationl. Behavioral experiments have shown that long-term dishabituation requires new protein synthesis, but the mechanism of transformation of short-term processes to long-term ones is unknown. In order to study this issue, we have labeled leech segmental ganglia with (32P)-ortophosphoric acid or (35S)-L-methionine and we have mimicked short-term learning by application of 50 µM 5HT for 5 min after 2-hr labeling, while long-term learning has been mimicked by repetitive stimulation (5 min, 50 µM 5HT for 4 times, every 90 min; 24 hr of total labeling incubation). Labeled proteins have been separated by two-dimensional electrophoresis and detected by autoradiography. A single 5-min treatment with 5HT was found to produce a general increase in protein phosphorylation. In the repetitive treatment experiments, in which samples were solubilized 18 hr after the last 5 min incubation with 5HT, it was similarly found that most of the proteins exhibited higher levels of phosphorylation. In addition, repetitive stimulations with 5HT modified [35S]-methionine incorporation into several proteins. In order to know whether protein phosphorylation is necessary to trigger protein synthesis following 5HT application. segmental ganglia were incubated in the presence of both 5HT and kinase inhibitor staurosporine; the presence of such an inhibitor during the 5 min repetitive stimulations resulted in a 20-50% inhibition of (35S1-methionine incorporation into proteins. These results suggest that repetitive treatment with SHT induces changes of protein synthesis and persistence of protein phosphorylation in leech central nervous system.
|Titolo:||Effect of repetitive treatments with serotonin on protein phosphorylation in the central nervous system of the leech C.N.S.|
|Data di pubblicazione:||set-1993|
|Settore Scientifico Disciplinare:||Settore BIO/14 - Farmacologia|
Settore BIO/09 - Fisiologia
|Citazione:||Effect of repetitive treatments with serotonin on protein phosphorylation in the central nervous system of the leech C.N.S. / Garcia-Gil M., Bottai D., Zaccardi M.L. and M. Brunelli. ((Intervento presentato al 45. convegno Congresso Nazionale della Società Italiana di Fisiologia tenutosi a pavia nel 1993.|
|Appare nelle tipologie:||14 - Intervento a convegno non pubblicato|