All Organisms Can Be Anesthetized, but There's No Point?

Area of Science:

• Biochemistry
• Evolutionary Biology
• Neuroscience

Background:

• Historically, anesthesia research focused on animal nervous systems, overlooking anesthesia potential in all life forms.
• Anesthetics interact with conserved proteins, including voltage-dependent Na+/Ca2+ channels (4D-NaV/CaV) and glutamate receptor channels (iGluR/GLR), present across diverse species.
• These essential proteins evolved early, predating eukaryotes and indicating strong selective pressure for their conservation.

Purpose of the Study:

• To propose an alternative hypothesis for the widespread susceptibility to anesthesia.
• To challenge the prevailing view that anesthesia susceptibility is solely a result of natural selection.

Main Methods:

• Comparative analysis of protein homologs targeted by anesthetics across different species.
• Review of evolutionary origins of voltage-dependent Na+/Ca2+ channels and glutamate receptor channels.
• Hypothesis formulation based on conserved protein targets and cellular function.

Main Results:

• Identified conserved protein targets (4D-NaV/CaV, iGluR/GLR) essential for cellular function across a wide range of species.
• Demonstrated that these targets predate eukaryotes, highlighting their fundamental role in life.
• Highlighted the strong selective pressure maintaining these essential channels.

Conclusions:

• The susceptibility of most organisms to anesthesia may stem from an intrinsic cellular vulnerability rather than solely from natural selection.
• This intrinsic weakness is linked to the fundamental nature and conservation of targeted ion channels essential for cellular life.