Charcot: Buddhist Leanings?

Jean-Martin Charcot, considered the father of modern neurology, had a complex personality featuring well-defined characteristics of introversion, competitiveness, irony, and skepticism. While biographers have described him as Republican, anticlerical, and agnostic, the literature also presents evidence that he came to admire Buddhism toward the end of his life; Charcot’s involvement with numerous patients suffering from incurable and insidious neurological diseases may have contributed to this change in attitude

Born to yawn? Understanding yawning as a warning of the rise in cortisol levels: Randomized trial

Background: Yawning consistently poses a conundrum to the medical profession and neuroscientists. Despite neurological evidence such as parakinesia brachialis oscitans in stroke patients and thermo-irregulation in multiple sclerosis patients, there is considerable debate over the reasons for yawning with the mechanisms and hormonal pathways still not fully understood. Cortisol is implicated during yawning and may link many neurological disorders. Evidence was found in support of the Thompson cortisol hypothesis that proposes cortisol levels are elevated during yawning just as they tend to rise during stress and fatigue. Objectives: To investigate whether saliva cortisol levels rise during yawning and, therefore, support the Thompson cortisol hypothesis. Methods: We exposed 20 male and female volunteers aged between 18 and 53 years to conditions that provoked a yawning response in a randomized controlled trial. Saliva samples were collected at the start and again after the yawning response, or at the end of the stimuli presentations if the participant did not yawn. In addition, we collected electromyographic data of the jaw muscles to determine rest and yawning phases of neural activity. Yawning susceptibility scale, Hospital Anxiety and Depression Scale, General Health Questionnaire, and demographic and health details were also collected from each participant. A comprehensive data set allowed comparison between yawners and nonyawners, as well as between rest and yawning phases. Collecting electromyographic data from the yawning phase is novel, and we hope this will provide new information about neuromuscular activity related to cortisol levels. Exclusion criteria included chronic fatigue, diabetes, fibromyalgia, heart conditions, high blood pressure, hormone replacement therapy, multiple sclerosis, and stroke. We compared data between and within participants. Results: In the yawning group, there was a significant difference between saliva cortisol samples (t = -3.071, P = .01). Power and effect size were computed based on repeated-measures t tests for both the yawning and nonyawning groups. There was a medium effect size for the nonyawners group (r = .467) but low power (36%). Results were similar for the yawners group: medium effect size (r = .440) and low power (33%). Conclusions: There was significant evidence in support of the Thompson cortisol hypothesis that suggests cortisol levels are elevated during yawning. A further longitudinal study is planned to test neurological patients. We intend to devise a diagnostic tool based on changes in cortisol levels that may assist in the early diagnosis of neurological disorders based on the data collected. Trial Registration: International Standard Randomized Controlled Trial Number (ISRCTN): 61942768; http://www.controlled-trials.com/ISRCTN61942768/61942768 (Archived by WebCite at http://www.webcitation.org/6A75ZNYvr)

In Bonobos Yawn Contagion Is Higher among Kin and Friends

In humans, the distribution of yawn contagion is shaped by social closeness with strongly bonded pairs showing higher levels of contagion than weakly bonded pairs. This ethological finding led the authors to hypothesize that the phenomenon of yawn contagion may be the result of certain empathic abilities, although in their most basal form. Here, for the first time, we show the capacity of bonobos (Pan paniscus) to respond to yawns of conspecifics. Bonobos spontaneously yawned more frequently during resting/relaxing compared to social tension periods. The results show that yawn contagion was context independent suggesting that the probability of yawning after observing others\u27 yawns is not affected by the propensity to engage in spontaneous yawns. As it occurs in humans, in bonobos the yawing response mostly occurred within the first minute after the perception of the stimulus. Finally, via a Linear Mixed Model we tested the effect of different variables (e.g., sex, rank, relationship quality) on yawn contagion, which increased when subjects were strongly bonded and when the triggering subject was a female. The importance of social bonding in shaping yawn contagion in bonobos, as it occurs in humans, is consistent with the hypothesis that empathy may play a role in the modulation of this phenomenon in both species. The higher frequency of yawn contagion in presence of a female as a triggering subject supports the hypothesis that adult females not only represent the relational and decisional nucleus of the bonobo society, but also that they play a key role in affecting the emotional states of others

Investigating determinants of yawning in the domestic (Equus caballus) and Przewalski (Equus ferus przewalskii) horses

International audienceYawning is rare in herbivores which therefore may be an interesting group to disentangle the potential function(s) of yawning behaviour. Horses provide the opportunity to compare not only animals living in different conditions but also wild versus domestic species. Here, we tested three hypotheses by observing both domestic and Przewalski horses living in semi-natural conditions: (i) that domestic horses may show an elevated rate of yawning as a result of the domestication process (or as a result of life conditions), (ii) that individuals experiencing a higher level of social stress would yawn more than individuals with lower social stress and (iii) that males would yawn more often than females. The study involved 19 Przewalski horses (PHs) and 16 domestic horses (DHs) of different breeds living in large outdoor enclosures. The results showed that there was no difference between the PH and DH in yawning frequency (YF). PHs exhibited much higher levels of social interactions than DHs. There was a positive correlation between yawning frequency and aggressive behaviours in PHs, especially males, supporting the idea that yawning may be associated with more excitatory/stressful social situations. A correlation was found between yawning frequency and affiliative behaviours in DHs, which supports the potential relationship between yawning and social context. Finally, the entire males, but not castrated males, showed much higher levels of yawning than females in both species. The intensity (rather than the valence) of the interaction may be important in triggering yawning, which could therefore be a displacement activity that helps reduce tension

Le bâillement : phylogenèse, éthologie, nosogénie

International audienceCharles Darwin would have said that yawning was a useless piece of physiology. If so, then how should the survival of this very stereotyped behavior among the poikilothermal and homoeothermic vertebrates, from the basic brained reptiles to human primates, whether in the air, on the land or in the sea be understand? This issue of the ethnological, neurophysiologic and neuropsychological literature depicts yawning as being associated with an alternation of "awake-sleep" rhythms, sexuality, and nutrition, where it appears as a reference behavior of the mechanisms stimulating the state of vigilance. In pharmacology, yawning is used as an indicator of dopamine-ocytocinergic pathway activity, but in the Parkinson patient the neurologist sees it as an expression of therapeutic dopaminergic activity. J.M. Charcot and his school considered yawning as a clinical sign, long since forgotten. However, many patients complain about excessive yawning. Iatrogenic causes are the most frequent and can be found among many neurological diseases: vasovagal syncope, migraine, epilepsy, hypophyseal tumor, or stroke. Our ability to achieve motor and emotional behavior in resonance with others is deeply rooted in hominid evolution, and probably explains the strange phenomenon of contagious yawning.Charles Darwin aurait dit du bâillement qu'il était un morceau de physiologie inutile. Mais alors, comment comprendre la survivance de ce comportement très stéréotypé chez les vertébrés poïkilothermes et homéothermes, des reptiles au cerveau rudimentaire, dit archaïque, jusqu'aux primates humains, dans le monde marin, aérien et terrestre? Cette revue de la littérature éthologique, neurophysiologique et neuropsychologique décrit le bâillement associé aux alternances des rythmes veille/sommeil, à l'alimentation, à la sexualité, où il apparaît comme un comportement témoin des mécanismes concourant à la stimulation de la vigilance. Alors que le bâillement est utilisé comme marqueur des voies dopamino-ocytocinergiques en pharmacologie, le neurologue le remarque chez le parkinsonnien, témoin de l'activité thérapeutique dopaminergique. J.M. Charcot et son école en avait fait un signe clinique, oublié depuis. Pourtant, l'excès de bâillements est une plainte exprimée par de nombreux patients. Les causes iatrogènes sont les plus fréquentes. On le retrouve au cours de nombreuses pathologies neurologiques: malaises vagaux, migraine, épilepsie, tumeurs sellaires et supra-sellaires, accidents vasculaires cérébraux. Plongée dans les racines de l'évolution des hominidés, la capacité à entrer en résonance motrice et émotionnelle avec autrui explique l'intrigant phénomène de la contagion du bâillement

Yawning: a cue and a signal

Yawning behaviour has been associated with a variety of physiological and social events and a number of corresponding functions have been attributed to it. Non-directed (self-directed behaviour) and directed yawning (display behaviour) might nonetheless encompass all expressions of yawning, although it is difficult to differentiate one type from the other in a social context. Here we analysed more fully the data from a study in which four combinations of sensory cues were presented to pairs of either cage mate or stranger rats. The aim of the re-analysis was to demonstrate that non-directed and directed yawning might be identified by their distinctive functions. All pairs of rats used olfactory cues to recognise each other as stranger or cage mate companions, but only stranger rats used auditory cues to detect and respond to each other’s yawning. Increasing defecation rates (i.e. an index of emotional reactivity) inhibited yawning in cage mate rats such that yawning frequency reflected each rat’s physiological state. These results suggest that non-directed yawning functions as a cue in cage mate rats and directed yawning as a signal in stranger rats. We hypothesize that cue yawning might be a regulatory act that animals perform to adjust muscle tone for a coordinated change of state. Signal yawning might indicate the physiological capacity of rats in male-male conflicts

"Flâneur neurologique in paris" – A guide to pinpointing the houses of famous neurologists in the late XIX century

INTRODUCTION: During the last quarter of the XIX century, Paris, France, particularly the Salpêtrière Hospital was the most important centre of reference of Clinical Neurology in the world. The group based on the Salpêtrière Hospital, led by Professor Charcot, who was arguably the most celebrated neurologist in Europe. OBJECTIVE: In this historical review, we present and locate the addresses of the houses of these famous Parisian neurologists from the late XIX century. DISCUSSION: At that time, Charcot and the triumvirate of his most famous pupils, Pierre Marie, Joseph Babinski and Gilles de la Tourette, lived in different streets of Paris, predominantly in a small cluster in the districts known as 7éme and 8émearrondissements (7th and 8th neighbourhoods). Professor Charcot lived in different streets and arrondissements of Paris, including the Rue du Faubourg Poissonnière, Paris IX; Cité de Trévise, Paris IX; Avenue du Coq, Paris IX; l'Hôtel de Chimay, Quai Malaquais Paris; and finally his most famous address at the Boulevard Saint-Germain, 217 (previously l'Hôtel de Varangeville), in the Faubourg Saint-Germain, Paris VII. (1884). CONCLUSION: The best urban organization in Paris provided an interaction between Charcot and other privileged minds of his day. We were remembering and visiting, as a "Flaneur Neurologique in Paris", the addresses of the houses of these famous and outstanding Parisian neurologists from the late XIX century

\u201cSpreading the word of the master\u201d: the contribution of Italian physicians in the early dissemination of Jean-Martin Charcot\u2019s theories

Jean-Martin Charcot (1825\u20131893) laid the foundations of modern neurology. The lectures he gave at La Salp\ueatri\ue8re Hospital in Paris attracted a large number of visitors from all over the world. Some of them transcribed these clinical lessons, translating and publishing them when returning home. This article discusses the contribution of some Italian physicians (Gaetano Rummo, 1853\u20131917; Domenico Miliotti; Giulio Melotti, 1857\u201319?; and Augusto Tebaldi, 1833\u20131895), who were pioneers in disseminating the ideas and discoveries of Charcot. The early Italian translations were based on personal handwritten notes and memories, not relying on official French versions personally revised or edited by Charcot himself. As such, their veracity cannot always be verified, particularly in the lack of other independent works reporting details on the same lectures. However, the Italian transcriptions providing information which cannot be found elsewhere in Charcot\u2019s corpus of works represent an invaluable and a unique source for fully understanding some theories by the French neurologist. Furthermore, they are the first documents providing original materials related to Charcot\u2019s teaching translated in a foreign language. The first Italian publications that included photographs of patients were deeply influenced by and clearly modeled on the famous volumes of the Iconographie photographique de la Salp\ueatri\ue8re and further contributed to the early dissemination of Charcot\u2019s theories