Dopaminergic Activity Measured in D₁- and D₂-Transfected Fibroblasts by Silicon-Microphysiometry

Abstract

The dopaminergic system implicated in human disorders such as Parkinson's disease, schizophrenia and prolactinomas, exerts its effects through several dopamine receptors. The diversity of the dopaminergic system has been revealed by the application of molecular biology techniques to this system, which allowed the identification of five different types of dopamine receptors to date. Even though the structure of these receptors has now been identified, their physiological roles are still under investigation. The coupling of the D₁ and D₂ dopamine receptor to second messengers has been investigated using cell lines transfected with the cDNAs of these receptors. However, until recently, there was no technique allowing non-invasive real-time measurement of the metabolic activity of cells after agonist stimulation. We present here real-time measurement of events induced by dopaminergic agents on either the D₁ or the D₂ dopamine receptors using a novel technique employing a silicon-based microphysiometer.