CHAPTER 1 1. 



EFFECT OF ALCOHOL ON THE SIMPLEST NEURAL ARCS. 



Pursuant to the principles on which this investigation was organized, 

 a study of the simplest reflex arcs under the influence of alcohol is held 

 to be of basal importance. Since the simple reflexes are conspicuously 

 free from direct voluntary control, as well as from the effects of practice, 

 they should furnish unambiguous and conclusive evidence of the effect 

 of alcohol on the particular group of tissues on which they depend. 

 As the simplest complete neuro-muscular process, they should furnish 

 a basis for the interpretation of the effects of alcohol on the more 

 complex ones, and, in conjunction with the rest of the systematically 

 related processes, they should furnish evidence of the relative inci- 

 dence of the effects of alcohol on the various neural levels of the same 

 individual. 



In view of its theoretical importance, quantitative knowledge of the 

 action of the simple human reflexes under alcohol is surprisingly scanty. 

 Bunge 1 asserts that reflex excitability is decreased by alcohol, basing 

 his assertion on a single apparently incomplete reference to J. C. Th. 

 Scheffer. 2 Sternberg 3 holds that alcohol operates at first to increase 

 the reflexes. He gives no references. 



The effect of alcohol on animal reflex is better known. In 1873, 

 Meihuizen 4 studied the effect of various drugs on the reflex excitability 

 of the frog to induction shocks. In his three specimens, 1 c.c. of 

 10 per cent alcohol decreased reflex excitability. The effect began 

 within 15 minutes and reached its maximum in from 45 to 90 minutes. 

 Of the many more or less casual observations which are scattered in 

 the physiological and pharmacological literature of animal experi- 

 mentation, we have found it impracticable to take account. That 

 doses of alcohol as large as 5 per cent of the circulation of the frog 

 produce complete inexcitability of the cord appears in the work of 

 Winterstein. 5 The most complete systematic study of the effect of 

 alcohol on the frog reflexes is that of Hyde, Spray, and Howat. 6 They 

 found that alcohol in doses stronger than 1 c.c. of 15 per cent solution 

 per 10 gm. of weight depressed all the reflexes of the frog. The depres- 

 sion differed for the different reflexes and for different doses. The 

 depression came in 10 minutes after the dose, and lasted 1 to If hours. 

 The relatively larger number of studies of the reaction of the inverte- 

 brate organisms to alcohol have no direct bearing on our present prob- 

 lem, since the anatomical and physiological conditions are so different. 



, Lehrbuch der Physiologic des Menschen, Leipsic, 1903, p. 209. 

 2 Scheffer, Nederl. Weekbl., 1900, p. 217 (not accessible, reference apparently incomplete). 

 3 Sternberg, Die Sehnenreflexe, Leipsic, 1893, p. 177. 

 4 Meihuizen, Archiv f. d. ges. Physiol., 1873, 7, p. 201. 

 'Winterstein, Zeitschr. f. allg. Physiol., 1902, 1, p. 19. 

 Hyde, Spray and Howat, Am. Journ. Physiol., 1912-13, 31, p. 309. 



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