THE HISTORICAL DEVELOPMENT OF NEUROPHYSIOLDGV 



47 



mobility by these animals and who later studied the 

 necropsy findings from the Cambridge laboratory 

 were astounded, and there can be no doubt that these 

 experiments gave a great impetus to neurosurgical 

 procedures in animals and in man. 



The physiology of the brain was now beginning to 

 unfold and to reveal itself in dynamic terms after 

 centuries of static representation in the two-dimen- 

 sional pages of the anatomy books. To clinical obser- 

 vation of impairment by disease states, three experi- 

 mental techniques were added : regional ablation, 

 stimulation (both mechanical and electrical) and 

 eventualh' the recording of the brain's own electricity. 



Mechanical and chemical irritation of the cortical 

 surface had suggested itself to many in\estigators down 

 the years, some of the attempts reaching the extremes 

 of the bizarre (see, for example, fig 32). Cabanis 

 (271), the celebrated physician and ideologue, had 

 provoked convulsive movements in muscle groups 

 that .seemed to vary with the region irritated. Earlier, 

 Haller (272), searching for irritability, had pricked 

 the brain and applied irritating fluids and concluded 

 that the grey matter was insensitive to stimulation 

 and that the white matter was the seat of sensation 

 and the source of movement. 



The Italian physiologists had been more successful. 

 The Abbe Fontana (273) and Caldani (274) (Gal- 

 vani's predecessor in the chair of anatomy at Bologna) 

 had convulsed their frogs by electrical stimulation 

 inside their brains. Rolando (255), following their 

 lead, extended his experiments to pigs, goats, sheep, 

 dogs and also to birds. The influential Magendie 

 however had failed and had proclaimed the cortex 

 electrically inexcitable; an opinion in which he was 

 backed by Flourens (252). In these days before the 

 neuron had been recognized as the unit of the nervous 

 system, before the pyramidal fibers were known to be 

 processes of cortical cells, there was no a priori reason 

 to expect electrical stimulation of the cortical surface 

 to have a peripheral effect, but soon an incontro- 

 \ertible proof was to be given. 



FIG. 32. One of the bizarre experiments of .Mdini on two 

 freshly-decapitated criminals. In the center is a voltaic pile, the 

 circuit through the heads being completed by conducting 

 arcs. .Mdini, Galvani's impetuous nephew, lacked the sagacity 

 and scientific acumen of his famous uncle. (From Aldini, G. 

 Essai Theorique el Experimental sur le Galvanisme. Paris; Fournier, 

 1804. 2 vol.) 



FIG. 33. Two pioneers in attempts to stimulate the brain: 

 the Abbe Fontana, physician to the Archduke of Tuscany and 

 professor of physics in the University of Pisa; and Caldani, 

 Galvani's predecessor in the chair of anatomy at Bologna. 

 (The portrait of Fontana is reproduced by courtesy of Dr. G. 

 Pupilli.) 



271. Cabanis, Pierre J.-G. Rapports du physique et du moral de 

 I'homme. Paris: Bibliotheque Choisie, 1830. 



272. ZiNN, JoHANN Gottfried (i 727-1 759) and A. Haller. 

 Memoir es sur les parties sensibles et trrilables du corps animal. 

 Lausanne: D'Arnay, 1760. 



273. Fontana, Felice (1720-1805). Acead. Sc. 1st. Bologna, 

 >757- 



274. Caldani, Leopoldo (1725-18 13). Institutiones phystologicae 

 et pathologicae. Leyden: Luchtmans, 1784. 



The pioneers were Fritsch & Hitzig (275) (two 

 young privatdocents in Berlin) with their now famous 

 experiments in which they u.sed a galvanic current 

 and from which evolved the idea of a 'motor cortex.* 



275. Fritsch, Gust.w Theodor (1838-1891) and Eduard 

 Hitzig (1838-1907). Uber die elektrische Erregbarkeit 

 des Grosshirns. .Irch. Anal. Physiol, miss. Med. Leipzig 37: 

 300, 1870. 



