Comment Re:Raised eyebrows... (Score 1) 382
IAAN. The authors make one huge assumption that effects of anesthetics on membrane proteins like ion channels would have to be mediated by specific and direct binding. They suggest that the similar effects of anesthetics on a wide range of different neurons and different organisms precludes an effect on ion channels, because these proteins will be very different in those different cells/animals. This is a flawed argument due to above mentioned assumption.
They're biophysical arguments support the idea that anesthetics change the Tm of the transition of the membrane from fluid (liquid-disordered) to gel (solid-ordered). The authors state that action potentials (nerve signal propagation) forces the membranes through 85% of this transition. They further state that this transition phase is distinguished by more compressible and more ion/molecule-permeable membranes. It is very likely that these two changes have effects on ion channels. The main players in action potentials are voltage gated ion channels, that have positively charged domains that must move through the membrane to control gating (although some people think these charges are not contacting lipids, many others think at least some of them do). Also, the opening of many, if not all of these channels involves some conformational change like a twisting that may be influenced by membrane compressibility (also fluidity and thickness) to varying degrees (an extreme example would be mechano-gated ion channels which can be opened by a stretching of the membrane away from the channel).
They're biophysical arguments support the idea that anesthetics change the Tm of the transition of the membrane from fluid (liquid-disordered) to gel (solid-ordered). The authors state that action potentials (nerve signal propagation) forces the membranes through 85% of this transition. They further state that this transition phase is distinguished by more compressible and more ion/molecule-permeable membranes. It is very likely that these two changes have effects on ion channels. The main players in action potentials are voltage gated ion channels, that have positively charged domains that must move through the membrane to control gating (although some people think these charges are not contacting lipids, many others think at least some of them do). Also, the opening of many, if not all of these channels involves some conformational change like a twisting that may be influenced by membrane compressibility (also fluidity and thickness) to varying degrees (an extreme example would be mechano-gated ion channels which can be opened by a stretching of the membrane away from the channel).
