Meeting Abstract
P2.91 Tuesday, Jan. 5 Neurotoxic Actions of 6-OHDA, 5,7-DHT, Manganese and Denervation on Serotonergic and Dopaminergic Innervation of Lateral Ciliated Cells of Gill of Crassostrea virginica MURRAY, S.*; HERNANDES, A.; CARROLL, M.A.; CATAPANE, Edward, J.; Medgar Evers College catapane@mec.cuny.edu
Cilia of the lateral cells of gill of Crassostrea virginica are innervated by serotonin (HT) and dopamine (DA) nerves that increase or decrease beating rates, respectively. 5,7-Dihydroxytryptamine (5,7-DHT) is a neurotoxin that destroys HT neurons. 6-Hydroxydopamine (6-OHDA) destroys DA neurons. Manganese (Mn) is an environmental toxin causing Manganism. Mn affects dopaminergic systems but the mechanism is unclair. Our studies show Mn disrupts dopaminergic control of lateral ciliated cells of gill of C. virginica. The present study contrasts actions of 6-OHDA, 5,7-DHT, Mn and denervation of the branchial nerve (BN) on ciliary activity. Animals were treated for 3-7 days with 6-OHDA or 5,7-DHT by injecting 500 μg into posterior adductor muscles and placed in containers of artificial sea water (ASW). For Mn treatments, right shells were removed and animals placed in containers of ASW with or without 500 μM of Mn. Denervation was done by cutting the BN. Beating of cilia was measured by stroboscopic microscopy. 6-OHDA caused supersensitivity to DA, an inability of inhibitory electrical stimulation (ES) of the BN to slow down beating, but no impairment to serotonergic innervation.5,7-DHT treatment resulted in supersensitivity to HT, an inability of ES of the BN to speed up cilia, but no impairment to dopaminergic innervation. Mn resulted in inability of DA and inhibitory ES of the BN to slow down cilia, but no impairment of serotonergic innervation. Denervations resulted in supersensitivity to DA. The study shows the 3 neurotoxins have different mechanisms of action. This is helpful to understand causes of and treatments of the disorders. This work was supported by grants 2R25GM06003-05 of NIGMS, 0516041071 of NYSDOE, 0622197 of NSF and P382A080040 of the USDE
