Meeting Abstract

P3.111  Jan. 6  A Signal Transduction Pathway for the Dopamine D1A Receptor in Transfected Human Embryonic Kidney Cells JONES, LP*; THURMAN, CL; BANTA, MD; University of Northern Iowa, Cedar Falls thurman@uni.edu

All five types of dopaminergic receptors use signaling pathways to convert chemical or electrical signals into cell function in response to dopamine (DA). Disrupting the linkage in any signal transduction pathway may be the underlying cause of dopaminergic diseases, such as Parkinson�s disease, Attention Deficit Hyperactivity Disorder (ADHD), and Alzheimer�s disease. A possible cause of a dopaminergic disease may be related to alterations in the dwell states of ion channels. The opening or closing of specific ion channels in Human Embryonic Kidney (HEK-293) cells transfected with DNA for D1A-type receptors were ascertained by studying the cell membrane current-voltage (I-V) relationships. These electrical properties of the cell membrane were measured using the patch clamp technique in the whole-cell configuration. As a control for each cell, an I-V relationship was determined before DA. The conductance of cell membrane typically decreased to a stable value. However, with DA the membrane conductance increased. Simultaneously, membrane potential (Vm) became more positive. In conclusion, initiating signal transduction via the D1A receptor triggers either the entry of positive ions into the cell or the exit of negative ions from the cell.