A USE OF THE SALAMANDER FOR INVESTIGATING AND TESTING THE ANTICONVULSANT PROPERTIES OF DRUGS

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

The neuropharmacological tests used in this study present a method in which the relatively simple salamander is employed for the investigation of the anticonvulsant properties of drugs. These procedures are applied to Tridione, phenobarbital, themisone, Dilantin and Phenurone, and yield information on the following topics for each drug: a) effective dose for each drug, b) peak and duration of action as determined from phylogenetically varied responses and effects on various levels of the nervous system, c) anticonvulsant properties as revealed by external behavior after Metrazol and repeated electrical shocks, d) anticonvulsant properties as indicated by electrical activity of brain and spinal cord immediately after an electrical shock and by counts of repeated electrical discharges during the 30 minutes following an injection of Metrazol.

A comparative analysis of the five drugs herein studied is graphically summarized in figures 1 to 5; the following points merit special attention. The righting reflex, though markedly depressed by phenobarbital, Tridione, and Phenurone, is only slightly affected by themisone and Dilantin. Themisone has a striking depressant effect on the corneal reflex and produces an easily recognized ataxia. Dilantin evoked a hyperactive response to tests for swimming, righting and walking. Tridione and Dilantin when compared with each other showed both similarities and contrasts in their anticonvulsant properties. Phenobarbital, themisone, and Phenurone are somewhat similar in that under their influence Metrazol produces mainly a prolonged tonic discharge with a diminished amount of clonic movements.

The probable role of the afferent portion of the nervous system in the mechanism of convulsant action is discussed.