An extracellular recording system has been designed for the detection of el
ectrical cell signals using p-channel or n-channel field-effect transistor
(FET) arrays with non-metallized gates. Signals from rat heart muscle cell
were recorded by these devices and the results described on the basis of an
equivalent circuit. This technique is sensitive enough to detect minute ch
anges of the extracellular membrane voltage and has potential applications
in drug screening. We show that known cardiac stimulants (isoproterenol, no
repinephrine) and relaxants (verapamil, carbamylcholine) have characteristi
c effects on the heart cells in terms of the changes of beat frequencies in
the absence or presence of corresponding agents. (C) 2001 Elsevier Science
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