Meeting Abstract

P3.96  Thursday, Jan. 6  Pharmacological Study of Dopamine Post-Synaptic Receptors of the Lateral Ciliated Cells of the Gill and Visceral Ganglia of Crassostrea virginica BROWN, C.*; ADEBESIN, D.; 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 Crassostra virginica are controlled by a reciprocal dopaminergic- serotonergic innervation from their ganglia. The innervation originates from the animal’s cerebral and visceral ganglia. Dopamine (DA) is the neurotransmitter which slows down and stops beating of the lateral cilia and serotonin is the neurotransmitter that accelerates the ciliary beating rates. DA are classified as D1-like and D2-like, each with respective subtypes. D1 receptors are coupled to G protein G_αs and activate adenyl cyclase. D2 receptors are coupled to the G protein G_αi, and directly inhibits the formation of cAMP by inhibiting the enzyme adenyl cyclase. Previous work of our lab showed that the DA receptors in the lateral cells of the gill are DA D2 type. To learn more about the DA receptors present in C. virginica we investigated the receptors in the visceral ganglia. Beating rates of cilia were measured by stroboscopic microscopy of isolated gill preparations as well as in VG-gill preparations, in which the innervation of the gill by the visceral ganglia was kept intact. The agonists, A68930, propylpiperdine, piribedil, BHT920, 2-bromo-ergocryptine, SKF89626; and the antagonist, supiride, droperidol, metoclopramide, ergonovine and chlorprothixene were tested to determine their efficacy in altering the beating rates of the lateral cilia. Analysis of the data indicates that the DA receptors present in the gill and visceral ganglia are the D2 type. The study also shows that this preparation is a good model for pharmacological studies of dopamine function as well as the pharmacology of drugs affecting biogenic amines in nervous systems.