Meeting Abstract
P1.115 Thursday, Jan. 3 The Neurotoxic Effects of Manganese on the Dopaminergic Innervation of the Gill of the Bivalve Mollusc, Crassostrea virginica HUGGINS, T.*; MARTIN, K.; CARROLL, M.A.; CATAPANE, E.J.; Medgar Evers College; Medgar Evers College; Medgar Evers College; Medgar Evers College catapane@mec.cuny.edu
Lateral cilia of the gill of Crassostrea virginica are controlled by a reciprocal serotonergic-dopaminergic innervation from their ganglia. Serotonin is an excitatory neurotransmitter at the ganglia and gill, causing cilio-excitation. Dopamine acts as an excitatory neurotransmitter within the ganglia, but as an inhibitory neurotransmitter at the gill, causing cilio-inhibition. In this study we examined the effects of manganese treatments on the nervous innervation of the lateral gill cilia of C. virginica. High levels of manganese is neurotoxic and causes Manganism, a Parkinson�s-like Disease in humans. Beating rates of the lateral cilia in gill epithelial cells were directly measured by stroboscopic microscopy of gill preparations which had both the ipsilateral cerebral and visceral ganglia attached (CG preparations), only the ipsilateral visceral ganglia attached (VG preparations) and isolated gill preparations. Animals were treated for 3 days with 0.1 and 0.5 mM manganese and then tested by superfusion of the cerebral ganglia, visceral ganglia and gill with dopamine and serotonin. Acute treatments with manganese resulted in a statistically significant, dose dependant impairment of the dopaminergic, cilio-inhibitory system, while having no effect on the serotonergic, cilio-excitatory system, which is in agreement with the method of action of manganese toxicity in humans. This study demonstrates that this preparation is useful as a model to study manganese neurotoxicity and the pharmacology of drugs affecting it and biogenic amines. This work was supported in part by grants 2R25GM06003-05 of the Bridge Program of NIGMS, 0516041071 of NYSDOE, 0622197 of the DUE Program of NSF and 67876-0036 of PSC-CUNY.
