Abstract
Prolonged electrical stimulation of the nervous system of conscious animals requires shielded electrodes which will not injure the nerves or cause undue local tissue reaction. The leads connecting the electrodes to the external electrical circuit must be capable of withstanding the almost continuous motion of a normal animal for periods of several months. The purpose of this report is to describe in detail the construction of electrodes and leads which have fulfilled the above requirements. The production of arterial hypertension by renal artery-nerve or splanchnic nerve stimulation with similar electrodes has been reported. 1 , 2 , 3 , 4
The electrodes are constructed of No. 18 fine silver wire and are imbedded in a molded lucite block (Fig. 1). The silver electrode wire is exposed on the inner surface of the lucite block to provide direct contact with the nerve. The obturator occludes the slot in the block after the nerve is in place. The hollow stainless steel terminal is filled with mercury and connected to a mercury-filled, double lumen rubber tube which provides electrical contact to the external electrical circuits.
A double lumen latex tube joined in a Y at the stainless steel terminal provides a means of flushing and cleaning the mercury columns whenever necessary. 1N HCl, followed by water, alcohol and air, is injected into one tube, flowing through that tube, through the hole in the stainless steel terminal and out through the second tube. Then this system is refilled with clean mercury.
Construction of electrodes. The electrode blocks are molded from powdered Lucite† at a temperature of 175°C and a pressure of approximately 1000 lbs./in 2 (Fig. 2).
Step 1: (Fig. 2, photo 1). The silver wire (b) is wrapped around the mandrel (c) and soldered to the stainless steel terminal (a). Soldering flux designed for stainless steel facilitates this step.‡
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