SCIENTIFIC PROCEEDINGS 



Abstracts of Communications. 



One Hundred Eleventh Meeting. 



Rockefeller Institute for Medical Research, New York City, 

 December 15, IQ20. 



President Calkins in the chair. 

 37 (1619) 



A pharmacodynamic analysis of cocain action of the cerebrum. 

 By D. I. Macht and Wm. Bloom. 



[From the Pharmacological Laboratory, Johns Hopkins University.] 



The effect of cocain and its chemical components was studied 

 on the intelligent behavior of albino rats in the circular maze. 

 25 rats were used altogether in the investigation. The animals 

 were trained in the circular maze until they were able to find their 

 way from the_ entrance to the center without making any errors 

 and in the shortest period of time. The drugs studied were then 

 injected subcutaneously and the effect of the same studied after 

 absorption. It was found that one milligram of cocain produced 

 a marked depression on the behavior of the rats as indicated by 

 incoordination, slowness of movement and loss of memory and 

 intelligence. Smaller doses (one thirtieth to one tenth milligram) 

 also produced distinct depression as indicated by the time of 

 performance and the number of errors made. 



An effort was made to ascertain whether cocain produced a 

 primary stimulation of the cerebrum. For this purpose very 

 small doses of cocain were injected. It was found that minute 

 quantities of the drug either failed to produce any effect or pro- 

 duced depression and in no case was there a primary stimulation 

 noted. 



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