High T sub(c) SQUID systems for magnetophysiology

Magnetophysiology is the use of a superconducting quantum interference device (SQUID) based instrument to detect neuromagnetic fields evoked by electrical stimulation of brain tissue slices. In this paper we show that a SQUID based on high temperature superconductors (HTSs) would have considerable advantages over a low T sub(c) device in this application. We construct a model of electrical activity in a hippocampal brain slice, which enables the neuromagnetic field to be determined as a function of position and distance from the tissue. We then describe the design of HTS SQUID systems for magnetophysiology and the two styles of system we are developing. Finally we use our model to show that an existing HTS SQUID magnetometer would give a superior signal to noise ratio compared to a low T sub(c) system for the hippocampal brain slice preparation at least. copyright 2001 Published by Elsevier Science B.V.