title: An exploratory evaluation of tyrosine hydroxylase inhibition in planaria as a model for parkinsonism.
abstract: Planaria are the simplest organisms with bilateral symmetry and a central nervous system (CNS) with cephalization; therefore, they could be useful as model organisms to investigate mechanistic aspects of parkinsonism and to screen potential therapeutic agents. Taking advantage of the organism's anti-tropism towards light, we measured a significantly reduced locomotor velocity in planaria after exposure to 3-iodo-L-tyrosine, an inhibitor of tyrosine hydroxylase that is an enzyme catalyzing the first and rate-limiting step in the biosynthesis of catecholamines. A simple semi-automatic assay using videotaped experiments and subsequent evaluation by tracking software was also implemented to increase throughput. The dopaminergic regulation of locomotor velocity was confirmed by bromocriptine, a drug whose mechanisms of action to treat Parkinson's disease is believed to be through the stimulation of nerves that control movement.
authors.affiliation: Department of Psychiatry, College of Medicine, University of Florida, Gainesville, FL 32611, USA. laszlo.prokai@unthsc.edu.
authors.forename: David
authors.initials: D
authors.lastname: Prokai
authors.forename: Thinh
authors.initials: T
authors.lastname: Nguyen
authors.forename: Kurt
authors.initials: K
authors.lastname: Kamrowski
authors.forename: Ashwin
authors.initials: A
authors.lastname: Chandra
authors.forename: Tatjana
authors.initials: T
authors.lastname: Talamantes
authors.forename: Lewis R
authors.initials: LR
authors.lastname: Baxter
authors.forename: Laszlo
authors.initials: L
authors.lastname: Prokai
mesh_terms: D000818:Animals; D001971:Bromocriptine / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D008027:Light; D008124:Locomotion / Q000187:drug effects / Q000528:radiation effects; D023421:Models, Animal; D007470:Monoiodotyrosine / Q000737:chemistry / Q000378:metabolism; D010300:Parkinson Disease / Q000201:enzymology / Q000378:metabolism / Q000473:pathology; D010932:Planarians / Q000201:enzymology*; D011485:Protein Binding; D011954:Receptors, Dopamine / Q000378:metabolism; D014446:Tyrosine 3-Monooxygenase / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: C523964:3-iodotyrosine; D011954:Receptors, Dopamine; D001971:Bromocriptine; D014446:Tyrosine 3-Monooxygenase; D007470:Monoiodotyrosine