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


Meeting Abstract

P3.78  Jan. 6  Control of the Lateral Ciliated Gill Epithelium of Crassostrea virginica (Bivalvia) by the Cerebral Ganglion and the Neurotoxic Effects of Manganese ROBINSON, Jasmine*; CARROLL, Margaret A.; CATAPANE, Edward J.; Kingsborough Community College; Medgar Evers College; Medgar Evers College catapane@mec.cuny.edu

Lateral gill cilia of Mytilus edulis has 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 cerebral ganglia in innervating lateral gill cilia of C. virginica. Ciliary beating rates were directly measured by stroboscopic microscopy of gill preparations which had the ipsilateral cerebral and visceral ganglia attached. Adding serotonin to gill increased ciliary beating rates which was antagonized by methysergide. Adding dopamine decreased beating rates and this was antagonized by ergonovine. Furthermore, superfusion of the cerebral ganglion with serotonin increased ciliary beating rates which was antagonized by methysergide. Superfusion with dopamine decreased beating rates and this was antagonized by ergonovine. Acute treatment of C. virginica with 1 mM manganese, a neurotoxin known to induce 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. The study demonstrates there is a reciprocal serotonergic-dopaminergic innervation of lateral gill ciliated cells which originates in the cerebral ganglion of the animal, 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 it and biogenic amines.

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