Development of an immunofluorescence assay module for determination of the mycotoxin zearalenone in water

Project Aquafluosense is designed to develop prototypes for a fluorescence-based instrumentation setup for in situ measurements of several characteristic parameters of water quality. In the scope of the project an enzyme-linked fluorescent immunoassay (ELFIA) method has been developed for the detection of several environmental xenobiotics, including mycotoxin zearalenone (ZON). ZON, produced by several plant pathogenic Fusarium species, has recently been identified as an emerging pollutant in surface water, presenting a hazard to aquatic ecosystems. Due to its physico-chemical properties, detection of ZON at low concentrations in surface water is a challenging task. The 96-well microplate-based fluorescence instrument is capable of detecting ZON in the concentration range of 0.09–400 ng/mL. The sensitivity and accuracy of the analytical method has been demonstrated by a comparative assessment with detection by high-performance liquid chromatography and by total internal reflection ellipsometry. The limit of detection of the method, 0.09 ng/mL, falls in the low range compared to the other reported immunoassays, but the main advantage of this ELFIA method is its efficacy in combined in situ applications for determination of various important water quality parameters detectable by induced fluorimerty—e.g., total organic carbon content, algal density or the level of other organic micropollutants detectable by immunofluorimetry. In addition, the immunofluorescence module can readily be expanded to other target analytes if proper antibodies are available for detection

Enhanced Dendritic Action Potential Backpropagation in Parvalbumin-positive Basket Cells During Sharp Wave Activity

In this study two-photon imaging and single cell electrophysiological measurements were carried out in PV? hippocampal interneurons to compare the dendritic calcium dynamics of somatically evoked backpropagating action potentials (BAPs) and in vitro sharp wave oscillation (SPW) activated BAPs at different distances from the soma. In the case of 300 lm thick, non-oscillating slices, the BAP-evoked Ca2? (BAP-Ca2?) influx propagated along the dendritic tree in a non-uniform manner and its amplitude gradually reduced when measured at more distal regions. In contrast to the evoked BAP-Ca2?s, the spontaneous SPWinduced Ca2? influx had only a small distance-dependent decrement. Our results suggest that similarly to nicotinic acetylcholine receptor activation, synaptic activity during hippocampal SPWs increases AP backpropagation into distant dendritic segments. Bath application of Nimodipine, a specific Ca2? channel blocker and tetrodotoxine decreased the amplitude of the somatically evoked Ca2? influx, which suggests that L-type Ca2? channels play an important role both during somatically evoked and SPW-induced BAPs