Effect of Methyl and Ethyl Alcohol Mixtures on Behaviour of Rats in a Maze.

Abstract

The pharmacological action of 2 or more drugs given in combination with each other is assuming great importance in recent pharmacological and toxicological research. The authors have been engaged in studying the pharmacological and toxicological effects of ethyl and methyl alcohol mixtures in various biological experiments, and one phase of the work is reported here.

The narcotic effects of ethyl and methyl, individually and in combination with each other, were studied on the behavior of the white rat in the circular maze. A total of 10 adult rats were used in the investigation, in addition to 6 rats which were used as controls. The rats were trained to solve the maze problem so that they could find their way from the periphery of the maze to its center, where food was placed, in the shortest period of time and with the least number of errors.

After the animals were thus trained, injections of weak alcohol solutions, 2 to 4%, were given repeatedly in doses of 2 cc. intraperitoneally and the effect on the running time and the number of errors noted. Several hundred such experiments were performed and the results obtained were summarized and averaged. The subjoined table expresses succinctly the effects produced. In the column marked “Running Time,” the ratio of the running time after the injections of the various drugs is expressed in terms of per cent of the normal running time of the animals before injecting the drugs. In the column giving the number of errors the same procedure is employed, namely, the number of errors after injections of the alcohol are expressed as percentages of the normal number of errors of the rats before injecting the drugs.

It will be noted that methyl alcohol (chemically pure) was less depressant than the ethyl alcohol and, indeed, showed a definite stimulating effect. Ethyl alcohol was definitely depressant, though not to a very great degree. The most interesting findings were those obtained with mixtures of ethanol and methanol in equal proportions. Injections of such mixtures, containing only half as much of either constituent as were used in the experiments with individual alcohols, produced a very marked depression.