Distribution of Molecules Related to Neurotransmission in the Nervous System of the Mussel Crenomytilus grayanus

Abstract

In bivalves neurotransmitters are involved in a variety of behaviors, but their diversity and distribution in the nervous system of these organisms remains somewhat unclear. Here, we first examined immunohistochemically the distributions of neurons containing different neurotransmitters, neuropeptides, and related enzymes, as well as the proliferative status of neurons in the ganglia of the mussel Crenomytilus grayanus. H-Phe-Met-Arg-Phe-NH2 (FMRFamide), choline acetyltransferase (ChAT), γaminobutyric acid (GABA) and tyrosine hydroxylase (TH) were found to be expressed by neurons in all the ganglia, whereas serotonin (5-HT) neurons were found only in the cerebropleural and pedal, but not visceral ganglia. Moreover, incubation of living mussels in the presence of a 5-HT precursor (5-HTP) confirmed the absence of 5-HT-containing neurons from the visceral ganglia, indicating that the "serotonin center" of the visceral nervous system is located in the cerebral ganglia. Furthermore, immunostaining of molecules related to neurotransmission together with α-acetylated tubulin demonstrated that this cytoskeletal protein may be a potential pan-neuronal marker in bivalves. Adult mussel neurons do not proliferate, but a population of proliferating PCNA-LIP cells which do not express any of the neurotransmitters examined, perhaps glia cells, was detected in the ganglia. These novel findings suggest that the nervous system of bivalves contains a broad variety of signal molecules most likely involved in the regulation of different physiological and behavioral processes. In addition, proliferating cells may maintain and renew glial cells and neurons throughout the lives of bivalves.

First Immunodetection of Sensory and Nervous Systems of Parasitic Larvae (Glochidia) of Freshwater Bivalve Nodularia douglasiae

“…The preadsorption of the diluted antiserum with 10 mg/ml BSA overnight at 4°C did not influence this staining, i.e., these antibodies recognized only serotonin and not BSA. Data from other groups have shown that these antibodies detect serotonin in adult bivalves and their planktotrophic larvae ( Voronezhskaya et al, 2008 ; Dyachuk and Odintsova, 2009 ; Dyachuk et al, 2015 ; Battonyai et al, 2018 ; Pavlicek et al, 2018 ; Yurchenko et al, 2019 ; Kotsyuba et al, 2020 ).…”

“…In addition to serotonin antibodies, we used an FMRFamide antibody to detect nervous system elements in the glochidia. FMRFamide-like peptides have been identified in the central and peripheral nervous systems of various taxonomic groups of mollusks ( Price and Greenberg, 1977 ; Boer et al, 1980 ; Painter and Greenberg, 1982 ; Schot and Boer, 1982 ; Voronezhskaya et al, 2008 ; Dyachuk and Odintsova, 2009 ; Zatylny-Gaudin and Favrel, 2014 ; Battonyai et al, 2018 ; Yurchenko et al, 2019 ; Kotsyuba et al, 2020 ). The antiserum employed in this study was generated in rabbits against synthetic FMRFamide (Phe-Met-Arg-Phe-amide) conjugated to bovine thyroglobulin (Immunostar Incorporated; Cat.…”

Effect of Air Exposure-Induced Hypoxia on Neurotransmitters and Neurotransmission Enzymes in Ganglia of the Scallop Azumapecten farreri

“…20091). According to the published data, this antibody reacts with FMRFamide in various animals, including mollusks (gastropods, bivalves, and poyplacophorans) [136][137][138][139], indicating that the antigen has been conserved evolutionarily across a broad range of species. The manufacturer confirmed, specifically, that these antibodies react with antigens in caenogastropods, chitons, gastropods (Helix pomatia, Aplysia sp., Ilyanassa obsoleta, Lymnaea stagnalis, Mopalia muscosa, abalones), and bivalves (Mytilus trossulus).…”

“…The preadsorption of the diluted antiserum with 10 mg/mL BSA overnight at 4 • C did not influence this staining, indicating that these antibodies recognized only serotonin and not BSA. Previous data have shown that these antibodies detect serotonin in mollusks [135][136][137][138]. FMRFamide-like peptides were identified in the central and peripheral nervous systems of various taxonomic groups of mollusks [53][54][55]120,123,139].…”

“…Immunohistochemical analysis was performed on freshly frozen sections, as described previously [136,138]. To eliminate non-specific binding, the samples were incubated in the blocking buffer (5-10% normal donkey serum (Baltimore Pike, PA, USA Jackson Im-munoResearch), 1-2% Triton-X 100 (Sigma), and 1% bovine serum albumin (Sigma) in 1 × PBS) overnight at 4 • C, with the primary antibodies diluted in this blocking buffer.…”