THE RELATION BETWEEN THE PHYSICAL STATE OF 

 BRAIN CELLS AND BRAIN FUNCTIONS —EXPERI- 

 MENTAL AND CLINICAL. 



By GEO. W. CRILE, M.D. 

 (Read April i8, 1913.) 



The brain in all animals (including man) is but the clearing- 

 house for reactions to environment, — for animals are essentially 

 motor or neuro-motor mechanisms, composed of many parts, it is 

 true, but integrated by the nervous system. Throughout the phylo- 

 genetic history of the race the stimuli of environment have driven 

 this mechanism, whose seat of power — the battery — is the brain. 



Since all normal life depends upon the response of the brain tcr 

 the daily stimuli, we should expect in health as well as in disease to 

 find modifications of the functions and the physical state of the 

 component parts of this central battery — the brain cells. Although 

 we must believe, then, that every reaction to stimuli, however slight, 

 produces a corresponding change in the brain cells, yet there are 

 certain normal, that is, non-diseased conditions which produce espe- 

 cially striking changes. The cell changes due to the emotions, for 

 example, are so similar, and in extreme conditions approach so 

 closely to the changes produced by disease, that it is impossible to 

 say where the normal ceases and the abnormal begins. 



In view of the similarity of brain cell changes, it is not strange 

 that in the clinic as well as in daily life, we are confronted constantly 

 by outward manifestations so nearly identical that the true under- 

 lying cause of the condition is too often overlooked or misunder- 

 stood. In our laboratory experiments and our clinical observations 

 we have found that exhaustion from intense emotion, from prolonged 

 physical exertion, from insomnia, from intense fear, certain toxe- 

 mias, hemorrhage, and the conditions commonly denominated sur- 



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