This hypothesis was effectively accepted as fact for the last 90 years but has recently been disproved. The observation was that the potency of inhalation anaesthetics correlated almost perfectly with their lipid solubility. This led to the theory that general anaesthesia was due solely to the dissolution of these agents in cell membranes with resultant interference with the normal functions of neurons.
Recent experimental evidence has shown that these agents work by binding to and potentiating the GABA receptor complex. It is presumed that the correlation with lipid solubility is a result of the binding site on GABA receptors being hydrophobic.