Comment on "Local impermeant anions establish the neuronal chloride concentration"

Area of Science:

• Neuroscience
• Cellular Biology
• Biophysics

Background:

• Neuronal chloride concentration is crucial for regulating inhibitory neurotransmission via GABAAR currents.
• The established understanding involves ion transporters in maintaining electrochemical gradients.
• Glykys et al. proposed an alternative mechanism involving impermeant anions.

Purpose of the Study:

• To critically evaluate the thermodynamic feasibility of the proposed mechanism by Glykys et al.
• To determine the role of local impermeant anions in neuronal chloride concentration.
• To reconcile the findings with fundamental principles of thermodynamics.

Main Methods:

• Thermodynamic analysis of ion transport and concentration gradients.
• Theoretical modeling of neuronal chloride homeostasis.
• Review and critique of existing literature and proposed mechanisms.

Main Results:

• The proposed mechanism by Glykys et al. violates the second law of thermodynamics.
• Establishing neuronal chloride concentration via impermeant anions would necessitate perpetual ion-motion machines.
• Ion transporters are essential for maintaining neuronal chloride gradients.

Conclusions:

• The conclusions by Glykys et al. are thermodynamically impossible.
• Neuronal chloride concentration is regulated by active ion transport mechanisms, not passive anion accumulation.
• The findings underscore the importance of adhering to thermodynamic principles in neuroscience research.