Localization of carbonic anhydrase in the nervous system.

Single-cell analyses of carbonic anhydrase demonstrate that this enzyme is selectively concentrated in the glial and choroid cells of the rat brain. The nerve cells show a very low carbonic anhydrase activity. This specific localization supports the view that glial carbonic anhydrase is implicated in a mechanism for the active transport of chloride from the capillaries to the interstitial and cerebrospinal fluids.