{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2023,10,22]],"date-time":"2023-10-22T23:57:08Z","timestamp":1698019028979},"reference-count":0,"publisher":"American Physiological Society","issue":"2","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Journal of Neurophysiology"],"published-print":{"date-parts":[[1985,2,1]]},"abstract":"<jats:p> Micropressure ejection of serotonin (5-hydroxytryptamine, 5-HT) produced excitatory responses in the L14 ink motor neurons of Aplysia that depended on the site of application. Ejection of 5-HT onto the cell body produced a slow response that showed variability in voltage sensitivity between preparations. In contrast, ejection of 5-HT onto the neuropil underneath the cell body produced a response whose amplitude was consistently a linear function of the holding potential, reversing near the predicted potassium equilibrium potential. Subsequent analyses focused on this second response. The neuropil response induced by 5-HT had a linear current-voltage relationship (reversing at ca. -80 mV), was associated with a decrease in input conductance, and was sensitive to changes in the concentration of extracellular K+. Serotonin application in artificial seawater (ASW) containing 30 mM K+ produced a response that reversed close to the altered Nernst potential for K+. The 5-HT response did not appear to be due to secondary activation of interneurons or to depend primarily on extracellular Ca2+, since ejection of 5-HT onto cells bathed in ASW containing 30 mM Co2+ produced responses comparable to, although somewhat attenuated from, those observed in ASW. Serotonin responses similar to those produced in ASW were obtained after perfusing the ganglion with ASW containing Co2+, 4-aminopyridine (4-AP), and tetraethylammonium (TEA). This suggests that the 5-HT-sensitive current is separate from the Ca2+-activated, fast, and delayed rectifying K+ currents. The 5-HT response appeared to be mediated by changes in levels of cAMP. Bath application of the phosphodiesterase inhibitors IBMX (3-isobutyl-1-methylxanthine) or Ro 20-1724, or the adenylate cyclase activator forskolin mimicked the 5-HT response by producing a slow inward current associated with a decrease in membrane conductance. Alteration of cellular cAMP metabolism modulated the response to 5-HT. Exposure of the ganglion to low concentrations of either Ro 20-1724 or forskolin potentiated the 5-HT response. Higher concentrations of these agents largely blocked the response to subsequent 5-HT applications. Bath application of the 8-bromo derivative of either cAMP or cGMP produced a slow inward current associated with a decrease in membrane conductance in cells voltage clamped at the resting potential. Responses to 5-HT were blocked, however, after exposure to 8-bromo-cAMP, but not to 8-bromo-cGMP. These results suggest that 5-HT produces a voltage-independent decrease in a steady-state potassium conductance that may be mediated by cAMP.(ABSTRACT TRUNCATED AT 400 WORDS) <\/jats:p>","DOI":"10.1152\/jn.1985.53.2.590","type":"journal-article","created":{"date-parts":[[2017,12,24]],"date-time":"2017-12-24T17:49:45Z","timestamp":1514137785000},"page":"590-602","source":"Crossref","is-referenced-by-count":9,"title":["Analysis of decreased conductance serotonergic response in Aplysia ink motor neurons"],"prefix":"10.1152","volume":"53","author":[{"given":"J. P.","family":"Walsh","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"J. H.","family":"Byrne","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"24","container-title":["Journal of Neurophysiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.physiology.org\/doi\/pdf\/10.1152\/jn.1985.53.2.590","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2019,9,9]],"date-time":"2019-09-09T01:38:58Z","timestamp":1567993138000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.physiology.org\/doi\/10.1152\/jn.1985.53.2.590"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1985,2,1]]},"references-count":0,"journal-issue":{"issue":"2","published-print":{"date-parts":[[1985,2,1]]}},"alternative-id":["10.1152\/jn.1985.53.2.590"],"URL":"https:\/\/doi.org\/10.1152\/jn.1985.53.2.590","relation":{},"ISSN":["0022-3077","1522-1598"],"issn-type":[{"value":"0022-3077","type":"print"},{"value":"1522-1598","type":"electronic"}],"subject":[],"published":{"date-parts":[[1985,2,1]]}}}