The mechanisms of general anesthesia, which was introduced about 170 years ago, remain poorly understood. Even less well understood are the effects of general anesthesia on the human body. Recently we identified 18 G-protein coupled receptor (GPCR) genes of Daphnia pulex, an invertebrate model organism. Phylogenetic analysis identified these genes to be the homologs of the human γ-aminobutyric acid, type B (GABAB) receptor, metabotropic glutamate receptors (mGluR), adrenergic receptor, serotonin (5-HT) receptor, dopamine receptor and muscarinic acetylcholine receptor (mAChR). Using reverse transcription and quantitative PCR techniques, we systematically measured the effects of propofol, etomidate and ethanol on these 18 GPCR mRNA expressions in Daphnia pulex.
