Control of the Lateral Ciliated Gill Epithelium of Crassostrea virginica (Bivalvia) by the Visceral Ganglion and the Neurotoxic Effects of Manganese


Meeting Abstract

P3.79  Jan. 6  Control of the Lateral Ciliated Gill Epithelium of Crassostrea virginica (Bivalvia) by the Visceral Ganglion and the Neurotoxic Effects of Manganese HUGGINS, Turkesha*; MARTIN, Kesha; CARROLL, Margaret A.; CATAPANE, Edward J.; Medgar Evers College; Medgar Evers College; Medgar Evers College; Medgar Evers College margie@mec.cuny.edu

Lateral gill cilia of Mytilus edulis have long been known to be controlled by a reciprocal serotonergic-dopaminergic innervation from their ganglia. Various other bivalves have been studied to lesser degrees and lateral cilia of most respond to serotonin and dopamine when applied to gill, indicating a possible neuro or endocrine mechanism. Lateral cilia in Crassostrea virginica are affected by serotonin and dopamine, but little work has been done with respect to the ganglionic control of the cilia. In this study we examined the role of the visceral ganglia in innervating lateral gill cilia of C. virginica. Ciliary beating rates were measured by stroboscopic microscopy of gill preparations which had the ipsilateral visceral ganglia attached. Superfusion of gill with serotonin increased beating rates which was antagonized by methysergide. Superfusion with dopamine decreased beating rates and this was antagonized by ergonovine. Superfusion of the visceral ganglion with serotonin increased ciliary beating rates which was antagonized by methysergide. Superfusion of the visceral ganglion with dopamine decreased beating rates and this was antagonized by ergonovine. Acute treatment of C. virginica with 1 mM manganese, a neurotoxin which induces Parkinson�s Disease in humans, reduced the cilio-inhibition caused by dopamine, which is in agreement with the method of action of manganese in humans. This study demonstrates that there is a reciprocal serotonergic-dopaminergic innervation of the lateral gill ciliated which originates in the visceral ganglion of the animal cells, similar to that of M. edulis and that this preparation is useful as a model to study manganese neurotoxcity and the pharmacology of drugs affecting biogenic amines.

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