THE INFLUENCE OF PENTYLENETETRAZOLE, STRYCHNINE AND CURARE ON THE ELECTRICAL ACTIVITY OF THE BRAIN AND CORD OF THE SALAMANDER

¹ Albers Biological Laboratory, Xavier University, and Department of Anatomy, College of Medicine, University of Cincinnati, Cincinnati, Ohio

The electrical activity of the brain and spinal cord of a salamander at rest consists of a dominant rhythm of 5 to 10 waves per second, on which are superimposed sequences of 12 to 14, and 18 to 22 waves per second of lower amplitude.

Under the influence of strychnine or of Metrazol, the brain and cord of the salamander, before and after transection of the cord, emit spike-like discharges, even in curarized animals. In the intact salamander, volleys of these spike-like discharges usually occur synchronously in brain and cord, yet they can occur independently.

Under the influence of Metrazol, the medulla usually anticipates other areas of the brain in emitting the first sustained spike-like discharge. In salamanders with a transected cord, the abundance of Metrazol-induced spikes from the portion of the cord detached from the brain is inversely proportional to the depth of curarization. It is suggested that this last phenomenon is probably due to partial "deafferentation" indirectly produced by curare.