Brown Sequard
Brown Séquard's spinal epilepsy (KOEHLER, 1994)
- Realizou exps que mostravam que a epilepsia espinal adquirida (pós corte na medula) podia ser passada para a prole.
- Não achava que era idêntica a epilepsia natural.
- Nem todos os filhotes adquiriam a condição epiléptica. Os que adquiriam a apresentavam de maneira um pouco distinta de seus pais
- Segundo Brown-Sequard: alteration or general organic tendency of the nervous system produced by the lesion, and that was deeply imprinted in the parents or in one of them". 198
- Darwin comentou com Wyman após ler uma das publicações de BS sobre o assunto.
- A primeira pub sobre o assunto foi antes da publicação do Origin mas é possível que BS soubesse das ideias de Darwin pois era bem conectado. 200
- França não era receptiva ao transformismo devido a cuvier e quando ficou preferiam lamarck
- No XIX-XX BS começou a ser desacreditado
- Geral das ideias de BS
- Brown-Sequard used the theories of Hall, Henle, Todd, and Bernard to build his own theory, which, however, has to be considered in the light of the lifelong development of his localization-concept of the nervous system, based on inhibition and dynamogenesis (excitation).78 He built a network system in which actions from a distance could inhibit or excite other areas of the nervous system. With this concept he was able to explain why lesions in different parts of the nervous system could produce the same effects. 203
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- Depois de 1860, durante 10 anos, Brown-Séquard não publicou novos trabalhos sobre a herança de caracteres adquiridos. Em 1870, no entanto (talvez por influência da publicação do Variation of animals and plants under domestication de Darwin), começou a apresentar uma série de comunicações à Société de Biologie nas quais informava sobre diferentes características – além da epilepsia – que eram transmitidas aos filhotes de porquinhos-da-Índia submetidos a certas cirurgias 360
- Cinco anos depois ele publicou na revista médica Lancet um artigo curto, mas muito claro, descrevendo todos os efeitos observados (Brown-Séquard, 1875). Este foi seu trabalho sobre o assunto que teve maior repercussão, sendo citado detalhadamente por Charles Darwin na segunda edição do seu livro Variation of animals and plants under domestication. 360 [neste artigo fala das orelhas, patas e etc]
- Maior interação de Darwin mais nos variatyions msm 1868 e1875
- Repercussão.
- Experimento foi replicado por Dupuy, Westphal e Obersteiner.
- Weismann contra. Dizia que era infecção. Wallace foi junto. Experimentos subsequentes descartaram infecção.
- Romanes fez estudos profundos finalizados prematuramente. Concluiu que a transmissão corria raramente. Mas não conseguiu resultados conclusivos para as patas, paltebras etc. Orelhas sim. Hill consegue paltebras depois
- Problemas experimentais relacionados a regressão do experimentador.
- Considerando-se a dificuldade de reprodução dos experimentos e a circunstância de que apenas em alguns casos era observada a transmissão dos efeitos aos descendentes, pode-se considerar que os experimentos de Romanes (com o auxílio de Hill) proporcionaram uma confirmação dos trabalhos de Brown-Séquard. 371
- Forte evidência experimental ignorada pelos neo-darwinistas.
- A conclusão principal deste trabalho é que os experimentos eram bem feitos e que as conclusões de Brown-Séquard pareciam bem fundamentadas; a aceitação ou rejeição dessas conclusões não se baseava em uma análise fria e rigorosa dessas pesquisas e sim, principalmente, dos pressupostos teóricos dos diferentes pesquisadores. 373
- Mais detalhes sobre as reações de Weismann em MARTINS 2010.
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- For Brown-Séquard, then, these observations about heredity were potentially signifcant for two reasons. They generally contributed to a contentious literature on the transmission of traumatic lesions, with supporting evidence that injuries or mutilations could indeed be inherited. But his observations also ofered some specifc details about the nature of this transmission. For instance, it was the “general organic disposition of the nervous system, determined by the lesion” that could be inherited, rather than the local lesion itself. This meant that the transmission was not completely faithful: the epileptiform condition and the physiology of the ofspring were diferent from those of the parents. The nervous system thus had some curious transgenerational quality, or an agency across generations. It could carry an apparently profound “impression” of a lesion from one generation to the next, such that the next-generation nervous system could remember, and re-enact, the traumatic experience of the parents. 383
- Some important features emerge from Brown-Séquard’s frst remarks on the heritable aspect of his epilepsy studies. First, Brown-Séquard discussed heredity explicitly and purposefully, but at all times he refrained from connecting his work to the larger debate about evolution that was, by late 1859 and 1860, well underway across the Channel. Brown-Séquard was likely aware of this British discourse as it was developing, according to Koehler (1994, p. 200),25 and so he could have joined the conversation if he so chose. His decision not to engage in the discourse can thus be taken as a measured and deliberate action. He clearly wanted to discuss heredity, but he did not want to be seen by his French colleagues associating with the theory of evolution itself. To side-step the evolutionary speculation that often accompanied discussions of heredity, Brown-Séquard instead framed his observations as a possible heredity feature of his physiological system. He was interested in “the alteration of a general organic disposition of the nervous system, determined by the lesion,” and how this impression of trauma could be passed to the next generation. In these publications, Brown-Séquard seems to give a clear message: he was talking aboutphysiology, not evolution; he was elaborating a hereditary aspect of induced epilepsy, and not engaging in theoretical musings.384-5
- BS como suporte retórico para o caso do Ateuchus.
- A herança de caracteres adquiridos pode resolver certos pepinos do darwin, como a cegueira dos animais cavernicolas 387
- Reitera o desinteresse frances
- Dá muito peso a trad:
- By May 1862, however, Darwin’s momentum with Brown-Séquard came to a halt. In Paris, the long-awaited French translation of the Origin had fnally been published.52 The translation was as controversial and as politicized as the translator herself—the feminist and republican Clémence Royer. Her atheistic and quasi-eugenic introduction to the Origin, and her unrestrained political commentary throughout the translation, whipped the “conspiracy of silence” in Paris into a veritable storm of controversy. As many historians have noted (Harvey 1997, chap. 4; Stebbins 1988, p. 127; Farley 1974, pp. 285–289; Geison and Farley 1974, p. 166), nothing could have tarnished Darwin’s ideas more in Paris than Royer’s handling of natural selection.
- Brown-Séquard’s review never appeared in the French press, and he appears never to have written to Darwin again. In fact, he stopped publishing on the hereditary aspect of the epilepsy studies for the rest of the decade. We can only speculate about why Brown-Séquard did not write the review he promised or why he stopped writing to Darwin, but it seems plausible that Brown-Séquard had decided to quietly disentangle himself from discourses of evolution following Royer’s publication and to disassociate himself from the evolutionists while the ground was still hot in Paris. An association with Royer or Darwin would have been professionally harmful in Paris in 1862, and especially with his community of biologists at the Société de biologie. In 1864, Brown-Séquard left London for the United States, where he took a professorship at Harvard University alongside Louis Agassiz and Asa Gray.54 He might have escaped the evolutionary debates in England, but it was hard to avoid the topic of evolution altogether in the 1860s, especially when one left France. 391-2
- Walsh não compra que CD gostava de BS só pelos seus méritos como experimentador:
- In lieu of a personal connection with Brown-Séquard, perhaps Darwin was trying to create an association by citation. This way Darwin’s theories of heredity would seem supported by, and in tune with, French experimental science. This could be a way of convincing the French community that his work was speaking to members of their own community, and that he had support from within their midst. Brown-Séquard’s work could have signifed all of these qualities for Darwin. 393
- Similar to his frst publications on the epilepsy studies, Brown-Séquard still did not make explicit links to evolution and remained focused on explicating the hereditary aspect of epilepsy as a feature of his physiological system. On paper, and if read on its own, Brown-Séquard’s claims still looked like French experimental positivism. But in the context of the 1870 Liverpool meeting, his work was given evolutionary meaning. His work was two-faced, in the literal sense—it could be read in two diferent ways, by two diferent audiences 394
- There was a politics to Darwin’s invocation of the “conclusive evidence” of Dr. Brown-Séquard, and a politics to Brown-Séquard’s careful presentation at the Liverpool meeting. To begin with the latter: Brown-Séquard surely knew, by 1870, that his epilepsy studies were enjoying an evolutionary life in Britain. How could he not? He presented at the Liverpool meeting in full knowledge that he was playing ball on Darwin’s turf. How could his presence at this meeting, and the contents of his presentation, be interpreted in any other way? And yet Brown-Séquard, true to form, practiced restraint at this meeting. He was French, after all, and one only need notice the absence of the word evolution in his presentation to be reminded of his intellectual home back in Paris and at the Société de biologie. Brown-Séquard was between two places—French and British biology—and he had the remarkable knack of speaking to both communities at once. When in France, the epilepsy studies were about a curious hereditary transmission of an induced epileptiform condition. When in Britain, and especially at the 1870 BAAS meeting, they were about inheritance and evolution.
- Darwin had diferent skin in this game. Restraint was not necessary. Unlike Brown-Séquard, Darwin had a biological community to win, not two to appease. A connection with Brown-Séquard, whether it was managed by correspondence or citation, meant a connection with France. This is spelled out plainly in Darwin’s correspondence. But it must also have been the quality of Brown-Séquard’s “conclusive evidence” that kept the epilepsy studies in print. Darwin was clearly excited by the hereditary facts produced in Brown-Séquard’s laboratory, and it helped him further elaborate his evolutionary framework. Brown-Séquard’s studies kept cropping up in Darwin’s work for the rest of his life, which indicates that there was more substance to the epilepsy studies than just what they could do for Darwin in the professional sense. There is some compelling material, for instance, in the second volume of Variation, in which Darwin puts Brown-Séquard’s studies in conversation with his theory of pangenesis (Darwin 1875, vol. 2, pp. 391–392). Brown-Séquard’s studies again come up in Francis Galton’s blood experiments that tested pangenesis, and both Darwin and Galton discussed Brown-Séquard’s studies at length; they appear genuinely puzzled about how Brown-Séquard’s experimental epilepsy functioned at a physiological level (Galton 1875, pp. 80–95). The epilepsy studies get invoked yet again, this time by August Weismann, who attempted to reconcile Brown-Séquard’s observations with the germline “barrier.” 396
- In 1881, just before his death, Darwin was still writing about Brown-Séquard. He had written a letter to Nature, simply titled “Inheritance” (Darwin 1881, p. 257). The heritability of acquired injury had been rightfully met with skepticism in times past, Darwin wrote, but “the subject, however, now wears a totally diferent aspect since Dr. Brown-Séquard’s famous experiments proving that guinea-pigs of the next generation were afected by operation on certain nerves.” Darwin characterized these studies as “famous,” as if he had not contributed to their fame by citing them so consistently in his works. In this same article in Nature, Darwin refers to Brown-Séquard as his “eminent friend and master,” yet no record of their friendship (or even contact) exists past Darwin’s last letter to Brown-Séquard in 1862. Is this another example of Darwin’s rhetorical strategy—his attempt at associating with French biology and Brown-Séquard in print—when such a connection did not exist in person? Perhaps I am too hasty in dismissing the existence of Darwin and Brown-Séquard’s friendship post-1862. Perhaps they did have a relationship that was conducted on the margins of meetings, in private, or in some other space that did not generate public record, or a record that has not been preserved throughout time. If this was a real relationship, then I wager that the lack of public record— its unverifability—was by Brown-Séquard’s design. Just like Darwin’s use of the honorifc “eminent friend and master” is a reminder of his interests in making a French connection, the difculty in proving this French connection is a reminder of Brown-Séquard’s caution in brokering this relationship with Darwin, his caution in approaching the subject of evolution, and his expertise in evolutionary diplomacy. 397
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