Isethionate may not be an inert substitute for extracellular chloride in the central nervous system.

Replacement of extracellular chloride with isethionate or methylsulphate causes an increased efflux of 1-[14C]-GABA from the in vivo superfused rat cuneate nucleus. This raises the question of the suitability of these anions as inert substitutes for chloride in studies on the ionic dependency of membrane phenomena in the central nervous system.