Serotonin and Dopamine Have Opposite Effects on Phototaxis in Larvae of the Bryozoan Bugula neritina (original) (raw)
Aquaculture, 2006
Catecholamines regulate several physiological processes in mollusks. Many pharmacological experiments have been conducted to determine the effects of adrenergic agonist and antagonist of catecholamine receptors on Meretrix meretrix metamorphosis. Results showed that adrenaline (AD) and noradrenaline (NA) had substantial effects (p b 0.05) on larval metamorphosis at concentrations ranging from 10 μM to 100 μM. 10 μM β-adrenergic receptor (AR) agonist isoproterenol showed the same inducement effect as that of NA and AD on metamorphosis, whereas the α-AR agonist phenylephrine had no significant effect at concentrations between 0.1 μM and 100 μM concentrations (p N 0.05). Furthermore, 1 μM β-AR antagonist propanolol, but not α-AR antagonist prazosin, depressed the larval metamorphosis induced by NA or AD. By immunocytochemistry, two cell bodies of β-adrenergic-like receptor, C/A1, C/A2, were observed in the cerebral/apical ganglion of competent larvae. In addition, there were other immunoreactive dots near C/A1 and C/A2. The results of pharmacology and immunocytochemistry suggests that βadrenergic-like receptor located in the larval CNS, might play a considerable role in the larval metamorphosis of M. meretrix by AD or NA.
Catecholamines Modulate Metamorphosis in the Opisthobranch Gastropod Phestilla sibogae
Biological Bulletin, 2000
Larvae of the nudibranch Phestilla sibogae are induced to metamorphose by a factor from their adult prey, the coral Porites compressa. Levels of endogenous catecholamines increase 6 to 9 days after fertilization, when larvae become competent for metamorphosis. Six-to nineday larvae, treated with the catecholamine precursor L-DOPA (0.01 mM for 0.5 h), were assayed for metamorphosis in response to coral inducer and for catecholamine content by high-performance liquid chromatography. L-DOPA treatment caused 20-to 50-fold increases in dopamine, with proportionally greater increases in younger larvae, so that L-DOPA-treated larvae of all ages contained similar levels of dopamine. A much smaller (about twofold) increase in norepinephrine occurred in all larvae. The treatment significantly potentiated the frequency of metamorphosis of 7-to 9-d larvae at low concentrations of inducer. In addition, L-DOPA treatment at 9 d increased aldehydeinduced fluorescence in cells that were also labeled in the controls, and revealed additional cells. However, all labeled cells were consistent with the locations of cells showing tyrosine-hydroxylase-like immunoreactivity. Catecholamines are likely to modulate metamorphosis in P. sibogae, but rising levels of catecholamines around the time of competence are insufficient alone to account for sensitivity to inducer in competent larvae.
Journal of Neurobiology, 1997
firmed in eggs using high-performance liquid chroma-ABSTRACT: The olfactory and accessory lobes tography with electrochemical detection. Morphometconstitute prominent histological structures within the ric analyses suggested that serotonin depletion larval and mature lobster deutocerebrum, and both dramatically slowed the growth of olfactory and accesare associated with a dense innervation from paired sory lobes, although glomeruli differentiated at the serotonergic nerve cells, the dorsal giant neurons normal time in both areas. The toxin exhibited a high (DGNs). During development, the cell bodies of the degree of specificity for serotonergic neurons and as-DGNs are the first central somata to express serotonin sociated target regions, and serotonin depletion per-(5-HT), and the onset of their 5-HT immunoreactivity sisted for at least 2 months following treatment. The coincides with the beginning of accessory lobe formagoal of future experiments is to determine which of the tion. In contrast, the olfactory lobe anlagen emerge cell types that innervate the olfactory and accessory much earlier and grow in the apparent absence of lobes are affected by toxin treatment, thereby resulting serotonin. The role of serotonergic input for the develin the retarded growth of these areas. ᭧ 1997 John opment of these brain structures was investigated in Wiley & Sons, Inc. J Neurobiol 33: 357-373, 1997 lobster embryos after serotonin had been depleted Keywords: 5,7-dihydroxytryptamine; serotonin; olfacpharmacologically with the neurotoxin 5,7-dihydroxytory lobes; accessory lobes; development tryptamine. A Ç90% reduction of serotonin was con-Correspondence to: B. S. Beltz shown that serotonin can inhibit (Haydon et al.,
Development, Growth and Differentiation, 2001
The neurotransmitter 5-hydroxytryptamine (5-HT, serotonin) plays an important role in a wide range of non-neural processes. Using immunofluorescence with an antiserotonin antibody, 5-HT was localized in the brain and in some neurons of the larval tail of Phallusia mammillata. To test the effect of 5-HT on development, we treated embryos with two different 5-HT receptor subtype antagonists. Treatment at the gastrula stage with 10 µM ondansetron, an antagonist of the 5-HT3 receptor, induced anterior truncation and a short tail. At 10 µM, ritanserin, a 5-HT2B receptor antagonist, induced larval phenotypes characterized by a roundish trunk region with flat papillae. The juveniles developed from these larvae had an abnormal cardiocirculatory system: their heart contractions were ineffective and their blood cells accumulated in the heart cavity. We conclude that an appropriate level of 5-HT is necessary for correct development and morphogenesis. Moreover, a different key role for multiple receptors in modulating the morphogenetic effects of 5-HT is suggested.
The Journal of Comparative Neurology, 1994
As a catecholamine, dopamine belongs to a class of molecules that have multiple transmitter and hormonal functions in vertebrate and invertebrate nervous systems. However, in the lobster, where many central neurons have been identified and the peripheral innervation pattern is well known, the distribution of dopamine-containing neurons has not been examined in detail. Therefore, immunocytochemical methods were used to identify neurons likely to contain dopamine and tyrosine hydroxylase in the central nervous system of the juvenile lobster Homarus gammarus. Approximately 100 neuronal somata stain for the catecholamine andlor its synthetic enzyme in the brain and ventral nerve cord. The systems of neurons labeled with dopamine and tyrosine hydroxylase antibodies have the following characteristics: 1) the two systems are nearly identical; 2) every segmental ganglion contains at least one pair of labeled neurons; 3) the positions and numbers of cell bodies labeled with each antiserum are similar in the various segmental ganglia; 4) six labeled neurons are anatomically identified; two interneurons from the brain project within the ventral cord to reach the last abdominal ganglion, two neurons from the commissural ganglia are presumably neurosecretory neurons, and two anterior unpaired medial abdominal neurons project to the hindgut muscles; and 5 ) no cell bodies are labeled in the stomatogastric ganglion, but fibers and terminals in the neuropil are stained. The remarkably small numbers of labeled neurons and the presence of very large labeled somata with far-reaching projections are distinctive features consistent with other modulatory aminergic systems in both vertebrates and invertebrates. o
Serotonin Depletion by 5,7-Dihydroxytryptamine Alters Deutocerebral Development in the Lobster
1970
firmed in eggs using high-performance liquid chroma-ABSTRACT: The olfactory and accessory lobes tography with electrochemical detection. Morphometconstitute prominent histological structures within the ric analyses suggested that serotonin depletion larval and mature lobster deutocerebrum, and both dramatically slowed the growth of olfactory and accesare associated with a dense innervation from paired sory lobes, although glomeruli differentiated at the serotonergic nerve cells, the dorsal giant neurons normal time in both areas. The toxin exhibited a high (DGNs). During development, the cell bodies of the degree of specificity for serotonergic neurons and as-DGNs are the first central somata to express serotonin sociated target regions, and serotonin depletion per-(5-HT), and the onset of their 5-HT immunoreactivity sisted for at least 2 months following treatment. The coincides with the beginning of accessory lobe formagoal of future experiments is to determine which of the tion. In contrast, the olfactory lobe anlagen emerge cell types that innervate the olfactory and accessory much earlier and grow in the apparent absence of lobes are affected by toxin treatment, thereby resulting serotonin. The role of serotonergic input for the develin the retarded growth of these areas. ᭧ 1997 John opment of these brain structures was investigated in Wiley & Sons, Inc. J Neurobiol 33: 357-373, 1997 lobster embryos after serotonin had been depleted Keywords: 5,7-dihydroxytryptamine; serotonin; olfacpharmacologically with the neurotoxin 5,7-dihydroxytory lobes; accessory lobes; development tryptamine. A Ç90% reduction of serotonin was con-Correspondence to: B. S. Beltz shown that serotonin can inhibit (Haydon et al.,
Cell and tissue research, 2003
A classical neurotransmitter serotonin (5-HT) was detected immunochemically using laser scanning microscopy at the early stages of Tritonia diomedea development. At the one- to eight-cell stages, immunolabeling suggested the presence of 5-HT in the cytoplasm close to the animal pole. At the morula and blastula stages, a group of micromeres at the animal pole showed immunoreactivity. At the gastrula stage no immunoreactive cells were detected, but they arose again at the early veliger stage. Antagonists of 5-HT(2) receptors, ritanserin and cyproheptadine, as well as lipophilic derivatives of dopamine blocked cleavage divisions or distorted their normal pattern. These effects were prevented by 5-HT and its highly lipophilic derivates, serotoninamides of polyenoic fatty acids, but not by the hydrophilic (quaternary) analog of 5-HT, 5-HTQ. The results confirm our earlier suggestion that endogenous 5-HT in pre-nervous embryos acts as a regulator of cleavage divisions in nudibranch molluscs.
Structure-Function of Serotonin in Bivalve Molluscs
Serotonin - A Chemical Messenger Between All Types of Living Cells, 2017
It has been observed that 5-HT excites the heart nerves in hard clam and regulates contraction and relaxation of the anterior byssus retractor muscle in the blue mussel. It is now known that 5-HT regulates several neurobehavioral systems such as mood, appetite, sleep, learning, and memory. It also plays critical roles in the physiological functions of peripheral organs involved in stress, growth, and reproduction in the animal kingdom. The present study reviews conserved 5-HT biosynthesis and its localization in the nervous system, and its physiological contribution to regulate reproduction in bivalves. In the cytosol of neurons, tryptophan hydroxylase catalyzes hydroxylation of l-tryptophan to 5-hydroxytryptophan, which is converted to 5-HT by aromatic l-amino acid decarboxylase. A 5-HT transporter and a monoamine oxidase reuptakes and metabolizes 5-HT to control the amount of released 5-HT in the nervous system and peripheral organs. Perikarya and fibers of 5-HT neurons are mostly located in the cortices and neuropil of ganglia, respectively, and innervate the gonad. However, distribution and 5-HT content differ among species and sexes and undergo seasonal variations associated with gonadal development. The present review pays a special attention to future research perspectives to better understand 5-HT regulation of reproduction in bivalves.
Mapping of serotonin-immunoreactive neurons of Anastrepha obliqua Macquart larvae
Revista Brasileira de Zoologia, 1999
Serotonin-immunoreactive neurons were identified in the central nervous system (CNS) of Anaslrepha obliquo Macqualt, 1835 wandering stage larvae. The PAP immunocytochemical method was applied to the entire CNS (whole mounts). About 90 neurons were visualized in the CNS (20 in the brain and 70 in the ventral ganglion). Both somata and axons were strongly stained. These neurons showed a segmental arrangement and bilateral symmetry. All processes presented a basic projection pattern, in which the major fibres travel contra laterally. Comparison of these neurons with serotonergic neurons described in other insects suggests order-specific traits such as cerebral clusters and presence of only one 5-HT immunoreactive neuron in the 8 th abdominal neuromere as well.