Distribution of Tetrodotoxin in the New Zealand Clam, , Established Using Immunohistochemistry and Liquid Chromatography-Tandem Quadrupole Mass Spectrometry. | LitMetric
Tetrodotoxin (TTX) is one of the most potent neurotoxins known. It was originally thought to only occur in puffer fish but has now been identified in twelve different classes of freshwater and marine organisms, including bivalves. Despite being one of the world’s most studied biotoxins, its origin remains uncertain. There is contradictory evidence regarding the source of TTX and its pathway through food webs. To date, the distribution of TTX has not been examined in bivalves. In the present study, 48 , a TTX-containing clam species endemic to New Zealand, were collected. Thirty clams were dissected, and organs and tissues pooled into five categories (siphons, digestive gland, adductor muscles, and the ‘rest’) and analyzed for TTX using liquid chromatography-mass spectrometry (LC-MS). The micro-distribution of TTX was visualized in the remaining 18 individuals using an immunohistological technique incorporating a TTX-specific monoclonal antibody. The LC-MS analysis revealed that siphons contained the highest concentrations of TTX (mean 403.8 µg/kg). Immunohistochemistry analysis showed TTX in the outer cells of the siphons, but also in the digestive system, foot, and gill tissue. Observing TTX in organs involved in feeding provides initial evidence to support the hypothesis of an exogenous source in .
Recently, an instrumental analysis using LC-MS/MS has been developed and validated for paralytic shellfish toxins (PSTs) and tetrodotoxin (TTX) in bivalve molluscs in Japanese domestic and overseas. The method for 11 PSTs and TTX in scallops was validated in accordance with a previous report and CODEX-STAN. The samples were prepared by adding the standard mixture of PSTs and TTX to scallop (Patinopecten yessoensis) homogenates, extracted with 1% acetic acid and then cleaned up using an ENVI-Carb (250 mg/3 mL) cartridge.
Center for Biomedical Studies, Department of Biological Sciences, University of Texas at Brownsville, TX 78520, USA; Laboratory of Emotions' Neurobiology, Instytut Biologii Doświadczalnej im. M. Nenckiego PAN, Poland; Instituto de Medicina Molecular, Universidade de Lisboa, Lisbon 1649, Portugal; Institute of Biophysics, Johannes Kepler University, Linz, Austria. Electronic address:
Similar to other brain regions, the neurons in the lateral septum (LS) are of heterogeneous populations. However, their resting membrane potential (RMP) on average is not too far apart. Cells were characterized based on biological markers by using brain slices, as under these in vitro conditions, neurons retain their morphologies.
An unusually large amplitude spontaneous miniature endplate potentials (gMEPPs) occur naturally at low frequency at the vertebrate neuromuscular junction. Unlike the normal miniature endplate potentials (nMEPPs), these gMEPPs have long duration and long time to peak. More strikingly, gMEPPs seem to be independent of extracellular and intracellular Ca and have a greater temperature sensitivity than nMEPPs.
Introduction: Interferential current (IFC) has been studied in several clinical trials for the treatment of bowel motility disorders, most often in children. However, only moderate effects are reported, and in contrast to IFC, the so-called placebo application is indiscernible. The mechanisms and neuroanatomic points of action remain elusive.
Initial proof-of-concept development of competitive lateral flow (LF) test strips involving red quantum dots (Qdots) is demonstrated with visible confirmation of the competitive displacement of Qdot-protein-saxitoxin (Stx) and -tetrodotoxin (Ttx) conjugates over 15 min. The measured limits of detection (LODs) for the best versions of the assays were in the 1-2 µg range when a bovine serum albumin (BSA)-Stx or -Ttx conjugate was used as the analyte for safety reasons and NIH ImageJ image analysis was applied. However, when one assumes that only one of the primary amines in BSA labeled with Stx or Ttx is needed as the "epitope" for capture and calculates the weight of the toxin adducts on an equal mole basis to that of 1 µg of toxin-BSA conjugate, the LODs are as low as 4.
