Serial determinations of regional cerebral blood flow in the rat using simple chronically implanted platinum wire microelectrodes.

The ability to reliably obtain serial determinations of regional cerebral blood flow (rCBF) over time in small animals using simple and inexpensively constructed platinum-wire microelectrodes has been investigated. Repeated measurements of local cortical flow were obtained on a daily basis using the hydrogen clearance technique in a group of 18 animals, in each of which, 6 electrodes were chronically implanted. Our studies have shown the simple microelectrodes utilised to give a low variability of results, as well as being well tolerated and provoking minimal tissue reaction even over prolonged periods of time. Under identical steady-state conditions, serial determinations of rCBF were obtained for up to one week, with a maximum variation in mean values of only 12%, a result that compares favourably with the known serial determination error for the technique in the shorter term.