The pre-nervous serotonergic system of developing sea urchin embryos and larvae: pharmacologic and immunocytochemical evidence.
Forty serotonin-related neurochemicals were tested on embryos and larvae of Lytechinus variegatus and other sea urchin species. Some of these substances (agonists of 5-HT1 receptors, antagonists of 5-HT2, 5-HT3 or 5-HT4 receptors, and inhibitors of the serotonin transporter, SERT) perturbed post-blastulation development, eliciting changes in embryonic/larval phenotypes typical for each class of receptor ligand. These developmental malformations were prevented completely or partially by serotonin (5-HT) or 5-HT analogs (5-HTQ, AA-5-HT), providing evidence for the putative localization of cellular targets. Immunoreactive 5-HT, 5-HT receptors and SERT were found in pre-nervous embryos and larvae of both L. variegatus and Strongylocentrotus droebachiensis. During gastrulation, these components of the serotonergic system were localized to the archenteron (primary gut), mesenchyme-like cells, and often the apical ectoderm. These results provide evidence that pre-nervous 5-HT may regulate early events of sea urchin embryogenesis, mediated by 5-HT receptors or the 5-HT transporter.
Buznikov
Gennady A
GA
Department of Cell and Developmental Biology, University of North Carolina School of Medicine, Chapel Hill, NC 27599-7090, USA. unclau@med.unc.edu
Peterson
Robert E
RE
Nikitina
Lyudmila A
LA
Bezuglov
Vladimir V
VV
Lauder
Jean M
JM
D000818:Animals; D007150:Immunohistochemistry; D007814:Larva / Q000378:metabolism*; D009420:Nervous System / Q000187:drug effects* / Q000196:embryology; D011985:Receptors, Serotonin / Q000145:classification / Q000187:drug effects; D012617:Sea Urchins / Q000196:embryology* / Q000254:growth & development; D012701:Serotonin / Q000502:physiology*; D012702:Serotonin Antagonists / Q000494:pharmacology*; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*
D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; D012701:Serotonin