The overall objective of this project is to identify the neurotoxic agent(s) produced by the dinoflagellate Pfiesteria piscicidae, and to understand the mechanisms by which a range of neuropsychological deficits, particularly cognitive deficits are induced in exposed persons. The project will benefit other parts of this Program Project, and will make contributions to understanding how and under what conditions the toxin produced by Pfiesteria-like dinoflagellates in Maryland (PTX) affects neurobiologic function in humans. It's specific goals are (1) to screen for neuroactive agent(s) produced by Pfiesteria-like dinoflagellates by utilizing in vitro assays of cellular metabolism, neurotransmitter receptor and transporter binding, and simple assays of neuronal function; (2) to determine how conditions of dose, duration, and route(s) of exposure affect response by testing effects of the isolated PTX(s) on behavior and neurochemistry in in vivo models of learning, and (3) to understand the molecular mechanism(s) of PTX neurotoxicity using the most up to date neurochemical and electrophysiological techniques (patch clamp and confocal microscopy) and receptor transporter radio-ligand binding and functional assays, as well as the effect of PTX on cell metabolism using the Cytocensor microphysiometer. Knowledge of the mechanism(s) of action of PTX will lead to suggestions for therapeutics.

Agency
National Institute of Health (NIH)
Institute
National Institute of Environmental Health Sciences (NIEHS)
Type
Research Program Projects (P01)
Project #
5P01ES009563-02
Application #
6203504
Study Section
Project Start
1999-08-01
Project End
2000-07-31
Budget Start
1997-10-01
Budget End
1998-09-30
Support Year
2
Fiscal Year
1999
Total Cost
Indirect Cost
Name
University of Maryland Baltimore
Department
Type
DUNS #
003255213
City
Baltimore
State
MD
Country
United States
Zip Code
21201
Drgon, Tomas; Saito, Keiko; Gillevet, Patrick M et al. (2005) Characterization of ichthyocidal activity of Pfiesteria piscicida: dependence on the dinospore cell density. Appl Environ Microbiol 71:519-29
Kazeto, Yukinori; Place, Allen R; Trant, John M (2004) Effects of endocrine disrupting chemicals on the expression of CYP19 genes in zebrafish (Danio rerio) juveniles. Aquat Toxicol 69:25-34
Miller, Todd R; Hnilicka, Kristin; Dziedzic, Amanda et al. (2004) Chemotaxis of Silicibacter sp. strain TM1040 toward dinoflagellate products. Appl Environ Microbiol 70:4692-701
Goto-Kazeto, Rie; Kight, Katherine E; Zohar, Yonathan et al. (2004) Localization and expression of aromatase mRNA in adult zebrafish. Gen Comp Endocrinol 139:72-84
Choich, J A; El-Nabawi, A; Silbergeld, E K (2004) Evidence of histamine receptors in fish brain using an in vivo [14C]2-deoxyglucose autoradiographic method and an in vitro receptor-binding autoradiographic method. Environ Res 94:86-93
Miller, Todd R; Belas, Robert (2004) Dimethylsulfoniopropionate metabolism by Pfiesteria-associated Roseobacter spp. Appl Environ Microbiol 70:3383-91
Miller, Todd R; Belas, Robert (2003) Pfiesteria piscicida, P. shumwayae, and other Pfiesteria-like dinoflagellates. Res Microbiol 154:85-90
Saito, Keiko; Drgon, Tomas; Robledo, Jose A F et al. (2002) Characterization of the rRNA locus of Pfiesteria piscicida and development of standard and quantitative PCR-based detection assays targeted to the nontranscribed spacer. Appl Environ Microbiol 68:5394-407
Trant, J M; Gavasso, S; Ackers, J et al. (2001) Developmental expression of cytochrome P450 aromatase genes (CYP19a and CYP19b) in zebrafish fry (Danio rerio). J Exp Zool 290:475-83
Kazeto, Y; Ijiri, S; Place, A R et al. (2001) The 5'-flanking regions of CYP19A1 and CYP19A2 in zebrafish. Biochem Biophys Res Commun 288:503-8

Showing the most recent 10 out of 13 publications