EFFECTS OF EXPOSURE TO LEAD (Pb) AND OTHER CATIONS ON THE DEVELOPMENT OF THE POSTERIOR LATERAL LINE IN EMBRYONIC ZEBRAFISH**

Lead (Pb) is a known environmental toxin, shown to have negative effects on growth and development of the central nervous system, including cognitive and behavioral disorders. We have previously examined the effects of exposure to Pb on the development of the posterior lateral line (PLL), an important sensory system, in embryonic zebrafish (Danio rerio) at 32-48 hours post fertilization (hpf). In contrast to initial expectations, we have found that 1µM Pb-acetate and 1µM PbCl2 increase the rate of development of the lateral line. Immunofluorescence targeting acetylated tubulin highlights the PLL, the extent of which is measured by the number of somitic motor neurons crossed in the time period examined. In this study, we are repeating these experiments in embryos at 32 hpf using PbCl2 and CaCl2 (as well other cations) in that we hypothesize that Pb may be substituting for calcium known to be important in many facets of early development