Electrophysiological activity of a mammalian sympathetic ganglion under hydrostatic and inert gas pressure

Abstract Rat superior cervical ganglia were exposed to helium (He), argon (Ar), krypton (Kr) and nitrogen (N 2 ) at 8 atm pressure as well as to 2, 8 and 14 atm hydrostatic pressure. Under these conditions, nerve action potentials and transsynaptic responses to a 6 Hz stimulation were recorded extracellularly. All the inert gases tested had an “anaesthetic” effect on the synapse. The anaesthetic action of He has not previously been described. Hydrostatic pressure has the reverse effect and facilitates synaptic transmission. The hydrostatic pressure reversal of inert gas narcosis has also been demonstrated.