Brain cell acid-base changes measured with ion-selective microelectrodes
Ion-selective microelectrodes (ISMs) provide an unparalleled tool for the simultaneous characterization of electrophysiologic and ionic properties of identified cells within functioning tissue. A simultaneous measurement of ionic activities and cell electrical properties remains a feat unmatched by any single tool for measuring bioelectric events or ionic species. A dramatic improvement in pH ISM technology came with the development of liquid membrane pH ISMs based on tridodecylamine (TDDA). Intracellular ISMs based on neutral carriers offer distinct advantages over glass ISMs. Liquid membrane ISMs are considerably easier to fabricate, generally more selective for principal ions, and respond faster than their glass counterparts. Indeed, pH ISMs based on TDDA, a neutral carrier that is highly selective for protons, are the easiest to fabricate among pH ISMs. They are the fastest, finest-tipped, and most selective double-barrel pH-sensitive ISMs fabricated to date. TDDA-based pH ISMs have become the microelectrode of choice for studying pHi changes from individual brain cells within intact tissues. © 1995, Elsevier B.V.
