Meeting Abstract
P1.178 Friday, Jan. 4 Manganese Treatments Decreases Immunofluorescence Emissions of Post-Synaptic Dopamine D2 Receptors OPOKU, R.*; CHEKAYEV, Y.; CARROLL, M.A.; CATAPANE, E.J.; Medgar Evers College; Medgar Evers College; Medgar Evers College; Medgar Evers College catapane@mec.cuny.edu
Manganese (Mn) a neurotoxin causing Manganism, a Parkinsons-like disease, disrupts dopamine (DA) neurotransmission. Gill lateral cell cilia of Crassostrea virginica are controlled by serotonergic-dopaminergic innervations. DA causes cilio-inhibition, serotonin cilio-excitation. Our lab showed post-synaptic DA receptors in gill cells are D2 type and Mn blocks cilio-inhibitory effects of DA by blocking DA post-synaptic receptors. Questions exist in the literature if Mn decreases the number of D2 receptors in brain. To test that we used antibody-antigen histoimmunofluorescence techniques to visualize DA D2 receptors in gill and ganglia of C. virginica. We used a 1° antibody against D2 receptors followed by FITC linked 2° antibody. Animals were treated with 500 µM of Mn for 5 days. Gill, cerebral and visceral ganglia were excised and exposed to 1° and 2° antibodies. Paraffin embedded sections were viewed with a phase contrast Zeiss epilume fluorescence microscope with a ProgRes C3 Peltier cooled camera. Antibody treated sections showed bright FITC fluorescence in lateral ciliated cells and other areas of gill and ganglia. Sections lacking 1° antibody treatment did not display similar fluorescence. We analyzed fluorescence intensity of 120 control and 80 gill lateral cells from animals treated with Mn using ImageJ software. Intensity of Mn treated cells was 70% less than controls. The study identifies DA D2 receptors in gill cells and cerebral and visceral ganglia, and shows a negative correlation between fluorescence intensity of DA D2 receptors in Mn treated animals and controls. The question if the decrease in intensity is due to decrease in actual number of receptors or if Mn alters protein conformation of D2 receptor and D2-ligand binding sites needs to be further explored.
