In Vivo Assessment of Neurotransmitter Biomarkers in Live Zebrafish (Danio rerio) Embryos

Neurotransmitters control various biological pathways in the body. Serotonin, mood elevating molecule, is a well-known species which serves as a neurotransmitter controlling gastrointestinal tract movement. Nitric Oxide (NO) is involved in neurotransmission processes and it is as well as biomarker of oxidative stress. Detection of neurotransmitters in live biological samples remains a challenge due to their low concentration, short life and high reactivity. Electrochemical biosensors are known to have several advantages over conventional methods for neurotransmitter detection. This poster presentation covers the effects of metal nanoparticle (CeO 2 , Cu and CuO) exposure on zebrafish ( Danio rerio ) embryos and the impact neurotransmitter concentration measured at the level of a single organ. . One of the primary targets of exposure to nanomaterials is the digestive system of embryos where materials can localize later in embryogenesis as feeding starts. We are employing a custom-made carbon fibre microelectrodes with a modified surface to quantify serotonin and nitric oxide within the size restraints of the zebrafish embryo intestine. Initial results comprise of fixing the exposure limits for each individual metal nanoparticles. We co-relate the electrical signal obtained from the insertion experiment to the concentration of the neurotransmitters. We hypothesize that the exposure to metal nanoparticles leads to the alteration of physiological pathways by interaction between the exposed materials and the available neurotransmitters pool at intestinal level.