A crustacean serotonin receptor: cloning and distribution in the thoracic ganglia of crayfish and freshwater prawn.
Serotonin (5-HT) is involved in regulating important aspects of behavior and a variety of systemic physiological functions in both vertebrates and invertebrates. These functions are mediated through binding to 5-HT receptors, of which approximately 13 have been characterized in mammals. In crustaceans, important model systems for the study of the neural basis of behaviors, 5-HT is also linked with higher-order behaviors, associated with different 5-HT receptors that have been identified at the physiological and pharmacological levels. However, no crustacean 5-HT receptors have been identified at the molecular level. We have cloned a putative 5-HT(1) receptor (5-HT(1crust)) from crayfish, prawn, and spiny lobster and have raised antibodies that recognize this protein in all three organisms. 5-HT(1crust) immunoreactivity (5-HT(1crust)ir) was observed surrounding the somata of specific groups of neurons and as punctate staining within the neuropil in all thoracic ganglia of crayfish and prawn. In the crayfish, 5-HT(1crust)ir was also found in boutons surrounding the first and second nerves of each ganglion and on the 5-HT cells of T1-4. In the prawn, 5-HT(1crust)ir was also found in axons that project across the ganglia and along the connectives. We found examples of colocalization of 5-HT(1crust) with 5-HT, consistent with the short-term modulatory role of 5-HT, as well as cases of serotonergic staining in the absence of a 5-HT(1crust) signal, which might imply that other 5-HT receptors are found at these locations. We also observed receptors that did not possess counterpart 5-HT staining, suggesting that these may also mediate long-term neurohormonal functions of serotonin.
Sosa
María A
MA
Institute of Neurobiology, University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico 00901. masosa@neurobio.upr.clu.edu
Spitzer
Nadja
N
Edwards
Donald H
DH
Baro
Deborah J
DJ
D000595:Amino Acid Sequence; D000818:Animals; D003400:Astacoidea / Q000737:chemistry* / Q000235:genetics; D003001:Cloning, Molecular / Q000379:methods; D017952:Ganglia, Invertebrate / Q000737:chemistry*; D008969:Molecular Sequence Data; D033541:Palaemonidae / Q000737:chemistry* / Q000235:genetics; D033521:Palinuridae / Q000737:chemistry* / Q000235:genetics; D011985:Receptors, Serotonin / Q000032:analysis* / Q000235:genetics; D013909:Thorax / Q000737:chemistry / Q000294:innervation*
D011985:Receptors, Serotonin