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C Lajonchere

Publications and source records attributed to C Lajonchere.

3 recordsLinked to original sources

Cutaneous sensory spots and the "law of specific nerve energies": history and development of ideas.

By use of suitable methods, different spots on the skin surface can be shown to be selectively sensitive to one of four sensory qualities in decreasing order of density: pain, touch, cool and warm. The presence of such spots was observed virtually simultaneously in the early 1880s by three independent investigators. Two papers on punctuate sensitivity of the skin were published in 1882 and 1883 by Magnus Blix of Uppsala University in Sweden; three papers were published in 1884 by Alfred Goldscheider, a German army doctor; and one was published in 1885 by Henry Donaldson of Johns Hopkins University in Maryland. Donaldson's findings originated from a serendipitous observation. In contrast, Blix's and Goldscheider's experiments were based on Johannes Muller's concept of "specific sense energies" and the extension of this idea to sensory qualities (the law of "specific nerve energies") by others, including Hermann von Helmholtz. The discovery of different types of sensory spots had considerable influence on other researchers of the period, including Max von Frey, but has only recently been substantiated by electrophysiological experiments.

Germany↗

Gilles de la Tourette and the discovery of Tourette syndrome. Includes a translation of his 1884 article.

In 1885, Gilles de la Tourette described 9 patients who suffered from a disorder characterized by involuntary movements, echolalia, echopraxia, coprolalia, and strange, uncontrollable sounds. In his article, Gilles de la Tourette presented some earlier descriptions of this disorder. To appreciate what first led Gilles de la Tourette to Tourette syndrome, however, it is necessary to turn to an article that he published a year earlier. In his 1884 article, Gilles de la Tourette cited several movement disorders that he thought were similar to each other, yet different from true chorea. After describing these disorders, namely, "jumping" of Maine, latah of Malaysia, and miryachit of Siberia, he briefly mentioned a boy in Charcot's ward in Paris, France, who seemed to exhibit the same condition. In an addendum, he then said that other cases were now surfacing in Paris and that he would write an additional article describing these individuals. To achieve a more thorough understanding of the events that led Gilles de la Tourette to his 1885 description of the disorder that now bears his name, we herein present an English-language translation of his 1884 article along with a commentary.

Eponyms↗

Gene expression in mental illness: a navigation chart to future progress.

An initial course in disentangling complex causal interactions in psychiatric illnesses, we suggest, is finding co-familial traits with classical Mendelian segregation. Starting with non-Mendelian traits, three methods can be used to find underlying Mendelian phenotypes. (1) Statistically-inferred latent traits, with more nearly Mendelian transmission than the measures from which they are derived, can serve as pointers to concrete Mendelian phenotypes. (2) Linkage of non-Mendelian traits to genetic markers, if it can be established, can be followed by searching for phenotypes that discriminate carriers from non-carriers of the imputed trait gene. (3) In the long run, the most successful method is likely to be direct refinement of non-Mendelian behavioral and physiological traits into more fundamental components.

Bipolar Disorder↗