A TECHNIQUE FOR RECORDING HEART‐RATE IN MOVING RATS¹

A TECHNIQUE FOR RECORDING ELECTROMYOGRAPHIC ACTIVITY IN FREELY‐MOVING RATS USING AN ALL‐PURPOSE SLIP RING COMMUTATOR1

“…2 were recorded from one Grass disc electrode chronically implanted under the skin and from one of the EMG electrodes. It is worth noting that this method permitted the recording of heart-rate signals of greater amplitude than was possible with our original technique (de Toledo and Black, 1965).A few years ago, Sutton and Miller (1965) described a mercury swivel designed to provide electrical recordings without movement artifact from freely moving animals; we found the mercury swivel unsatisfactory for noise-free recordings. The main objections were interference due to movement artifact caused when the swivel rotated rapidly and the frequent oxidation of the mercury.…”

“…2 were recorded from one Grass disc electrode chronically implanted under the skin and from one of the EMG electrodes. It is worth noting that this method permitted the recording of heart-rate signals of greater amplitude than was possible with our original technique (de Toledo and Black, 1965).…”