36 



HANDBOOK OF PHYSIOLOGY 



NEUROPHYSIOLOGY I 



Institute at Bonn, tmd Rudolph Lotze (197), pro- 

 fessor of Philosophy at Gotlingen. Back and forth the 

 battle raged, swinging from physiology into meta- 

 physics and back again into experiment. The argu- 

 ments all centered around the problems of whether a 

 spinal animal was sentient and conscious, and whether 

 its movements were purposeful. Was such an animal 

 intelligent? Did it have memory? Pfliiger espoused the 

 idea of consciousness in the cord, Lotze denied it; 

 both were dogmatic inn to neither can we look for 

 advancement of knowledge of the central nervous 

 system in this context. 



In the nineteenth century, while Marshall Hall was 

 still alive, the nature of inhiiiition became of major 

 interest to physiologists and before the end of the 

 century was to have its role in reflex activity demon- 

 strated by Sherrington. Although the po.ssibility of 

 inhibition had been suggested by several workers, the 

 actual phenomenon had first been observed (and re- 

 jected as an error of experiment) by Volkmann (198) 

 in 1838 in relation to the action of the vagus on the 

 heart. It was again observed, and this time accepted, 

 by the Weber brothers (199) in 1845. The elder 

 brother, Ernst, held the joint chair of anatomy and 

 physiology at Leipzig until Carl Ludwig came in 1866 

 to take over the latter section and set up his famous 

 institute. The technique of the classic experiment that 

 established the existence of vagal inhibition was the 

 stimulation by a voltaic pile of both vagi of the frog. 

 Later the Webers found that unilateral stimulation 

 had the same effect and they confirmed the result by 

 stimulating the vagus of a cat with an induction cur- 

 rent. They reported this discovery, one of the land- 

 marks of nerve physiology, at the Congress of Italian 

 Scientists held in Naples in 1845 (which accounts for 

 their publication being in Latin rather than in 

 German). This type of inhibition, like that which was 

 eventually evoked to explain Bernard's (200) obser- 

 vation of the influence of the chorda tympani on the 



197. Lotze, Rudolph Heinrich (1817-1881). Instinct. In: R. 

 Wagner. Handwortrnbuch. pt. ■!. Brunswick: Vieweg, 184.!- 



1853- 



ig8. Volkmann, Alfred Wilhelm (1800-1871). Uber Re- 

 flexbewegungen. Arch. Anat. u. Physiol. 15, 1838. 



igg. Weber, Eduard Friedrich Wilhelm (1806-1871) and 

 Ernst Heinrich Weber (i 795-1878). Experimenta, 

 quibus probatur nervos vagos rotations machinae gal- 

 vano-magneticae irritatos, motum cordi retardare et 

 adeo intercipare. Ann. Univ. Med.., Milano 20: 227, 1845. 



200. Bernard, Claude (1813-1878). Recherches anatomiques 

 et physiologiques sur la corde du tympan, pour servir a 

 I'histoire de I'hemiplegie faciale. Ann. med.-psychol. i : 408, 

 '843- 



submaxillary blood \'essels, seemed simple to later 

 physiologists faced with the complexities of inhibition 

 in the central nervous system. These had to await 

 exploration by Sherrington. 



An enduring interest of Sherrington and one ex- 

 haustively explored by him in the laboratory was re- 

 ciprocal inner\ation of antagonist muscles, and many 

 of his publications were on this subject. The attempt 

 of Descartes (25) in the seventeenth century to reach 

 an explanation based on channeling of vital spirits 

 had no immediate successor. In the early part of the 

 nineteenth century Charles Bell (201) had postulated 

 the existence of peripheral inhibition by insisting on 

 the need for nerves which had the opposite of an 

 excitatory effect on muscle. "The nerves," he said, 

 "have been considered so generally as in.struments for 

 stimulating the muscles, without thought of their act- 

 ing in the opposite capacity, that some additional 

 illustration may be necessary." He went on to describe 

 an experiment in which contraction of a flexor muscle 

 coincided with imposed relaxation of its opponent 

 extensor. 



The possibility of a peripherally exerted inhiljition 

 of muscle contractility attracted many people at 

 about this time. One of the earliest was a Dr. West 

 (202) of Alford in Lincolnshire (who had heard Bell's 

 lectures at the Royal College of Surgeons). \Vest's 

 suggestion was that contraction was an inherent prop- 

 erty of muscle and that the action of the nerve supply- 

 ing it was not to evoke, but to 'restrain' or 'rein' this 

 innate tendency to contract. He explained a volun- 

 tary contraction as a withdrawal of this nervous re- 

 straint "so as to allow the peculiar property of muscu- 

 lar fibre to shew itself." The publication of West's 

 hypothesis provoked some expostulation, one anony- 

 mous correspondent saying this was "certainly one of 

 the clumsiest contrivances that nature was ever 

 accused of" The mechanism of rigor mortis was not 

 understood at this time and West felt that his theory 

 off"ered a possible explanation. The idea was also 

 present in the arguments of many others, for example 

 those of Engel (203), of Stannius (204) and of Duges 



201. Bell, C. On tiio ner\es of the orbit. Phil. Trans. 113: 289, 

 1823. 



202. West, R. Uvedale. On tlic inHucnce of the nerves over 

 muscular contractility. Ryan's Med. Surg. J. 1 : 24, 245, 

 445, 1832. 



203. Engel, Joseph. Uber Muskelreizbarkeit. ^Ischr. Gesellsch. 

 Arize, yVien i : 205, 252, 1849. 



204. Stannius, Hermann (1808-1883). Untcrsuchungen iiber 

 die Leistungsfahigheit der Muskeln u. Todtenstarre. 

 Vierordt's Arch, physwl. heilk. i, 1852. 



