A new method for recording surface compound potentials in sympathetic ganglia from mouse, rat, and guinea pig—application to muscarinic and nicotinic depolarizations

Abstract

We present a new method for electrophysiologic investigations in isolated autonomous ganglia of a variety of laboratory animals. This method enables determination of surface compound potentials in ganglia and changes induced by pharmacologic compounds. Advantages of our methods are as following: (1) the method is relatively simple and does not require sophisticated experimental setups, with minor modifications it is adaptable to investigate ganglia of varying sizes; (2) the signal amplitude is comparable or even higher when compared with signals obtained by other methods; (3) the apparatus allows fast addition and removal of the investigational compounds and thus the determination of acute and subacute desensitizing effects; and (4) fast preparation and minor tissue injuries during preparation of the ganglia allow determination of surface potential changes over a time period of up to 2 days without qualitative changes of the parameters. In this report we demonstrate the validity of this method using superior cervical ganglia from rat, mouse, and guinea pig. Agonists used to trigger potential changes are the cholinergic agonists acetylcholine, muscarine, nicotine, and carbachol. The possibility of receptor desensitization by these compounds is investigated by repeated application over 5 h.