Brown-Séquard and cerebral localization as illustrated by his ideas on aphasia

Brown-Séquard's concept of localization was built on the phenomena of inhibition and dynamogenesis, constituting a dynamic system in which reflex mechanisms, that played a part not only in the spinal cord but in the brain as well, were considered of particular importance. The use of this concept is considered in Brown-Séquard's discussion of the subject of cerebral localization, and especially of aphasia. The origin and development of Brown-Séquard's ideas on aphasia from 1861 onwards are discussed, as is the part he possibly played in the transfer of knowledge from Paris to London (Broca and Jackson). In the 1870's Brown-Séquard debated on cerebral localization with Charcot before the Société de Biologie. Opposing the cluster theory of localization, Brown-Séquard developed the theory of "réseau de cellules anastomosées", a kind of network theory in which scattered cells subserving the same function are connected by nerve fibers. This was to him a plausible theory, with which he was able to explain the fact that damage in several locations may produce the same effect, and, to account for observations that some functions remain unimpaired despite extensive brain-injury. Although Brown-Séquard's arguments were not always valid, because they were based on imprecise observations, his dynamic model, nowadays, seems valuable. He influenced "anti-localizers" such as Goltz, but also Jackson and probably Von Monakow and Sherrington.     

The impossible interview with the man of the hidden biological structures. Interview by Paolo Mazzarello

This paper presents an "impossible interview" to Professor Camillo Golgi, placed in time in December 1906. The Italian Professor Golgi from Pavia has been awarded the Nobel Prize for Physiology or Medicine ex aequo with the Spanish anatomist Santiago Ramón y Cajal. Both scientists have obtained the award for their work on the anatomy of the nervous system. However, they have opposite views on the mechanisms underlying nervous functions. Golgi believes that the axons stained by his "black reaction" form a continuous anatomical or functional network along which nervous impulses propagate. Ramón y Cajal is the paladin of the neuron theory, a hypothesis questioned by Golgi in his Nobel lecture of Tuesday, December 11. After the ceremony, an independent journalist has interviewed Professor Golgi in the Grand Hotel in Stockholm. Excerpts about his education, his main scientific discoveries, and his personal life are here given (reconstructing the "impossible interview" on the basis of Golgi's original writings).     

Visual images in Luigi Galvani's path to animal electricity

The scientific endeavor that led Luigi Galvani to his hypothesis of "animal electricity," i.e., of an electricity present in a condition of disequilibrium between the interior and the exterior of excitable animal fibers, is reviewed here with particular emphasis to the role played by visual images in Galvani's path of discovery. In 1791 Galvani formulated his model of neuromuscular physiology on the base of the image of a muscle and a nerve fiber together as in a "minute animal Leyden jar." This was the last instance of a series of physical models that accompanied Galvani's experimental efforts in the search of a theory capable of accounting for the electric nature of nerve conduction in spite of the many objections formulated in the eighteenth century against a possible role of electricity in animal physiology.     

Aspects of the history of the nerves: Bell's theory, the Bell-Magendie law and controversy, and two forgotten works by P.W. Lund and D.F. Eschricht

The French physiologist Fran?ois Magendie showed, in 1822, that the anterior roots of the spinal nerves are motor and the posterior sensory. The English anatomist Charles Bell claimed the discovery, but his claim was based on republications of papers in which the wording had been altered to be consistent with Magendie's findings. Bell also appropriated Herbert Mayo's discoveries of the functions of the fifth and seventh cranial nerves. Bell repeated his claims in a number of influential publications, supported by his brothers-in-law John and Alexander Shaw. And for a century and a half, Bell figured as the discoverer in most references to the subject. During this period, several reviewers did go back to Bell's original papers, disclosing Bell's falsifications in the republished texts. But Magendie was not definitely acknowledged as the discoverer of the function of the spinal nerve roots until Cranefield's (1974) treatise. Cranefield, as did all other reviewers, overlooked accounts from 1825 by P.W. Lund and F.D. Eschricht. They critically reviewed Bell's early publications and reached conclusions similar to those of Cranefield concerning the roles of Bell and Magendie in the discovery of the function of the spinal nerve roots.     

Aspects of the History of the Nerves: Bell’s Theory,the Bell-Magendie Law and Controversy,and Two Forgotten Works by P.W. Lund and D.F. Eschricht

The French physiologist François Magendie showed, in 1822, that the anterior roots of the spinal nerves are motor and the posterior sensory. The English anatomist Charles Bell claimed the discovery, but his claim was based on republications of papers in which the wording had been altered to be consistent with Magendie’s findings. Bell also appropriated Herbert Mayo’s discoveries of the functions of the fifth and seventh cranial nerves. Bell repeated his claims in a number of influential publications, supported by his brothers-in-law John and Alexander Shaw. And for a century and a half, Bell figured as the discoverer in most references to the subject. During this period, several reviewers did go back to Bell’s original papers, disclosing Bell’s falsifications in the republished texts. But Magendie was not definitely acknowledged as the discoverer of the function of the spinal nerve roots until Cranefield’s (1974) treatise. Cranefield, as did all other reviewers, overlooked accounts from 1825 by P.W. Lund and F.D. Eschricht. They critically reviewed Bell’s early publications and reached conclusions similar to those of Cranefield concerning the roles of Bell and Magendie in the discovery of the function of the spinal nerve roots.     

The impossible interview with the man of the neuron doctrine. Interview by Edward G Jones

This paper follows the form of that by Mazzarello that precedes it (Mazzarello, 2006) and presents an imaginary interview with Santiago Ramón y Cajal in December 1906. A few days earlier Cajal had been awarded the Nobel Prize for Physiology or Medicine, an award that he shared equally with Professor Camillo Golgi. Golgi had been recognized for his work as a pioneer into investigations of the nervous system, primarily on account of his discovery of the "black reaction" of silver chromate impregnation of whole nerve cells and their processes. Cajal had been recognized for his implementation of that method and for laying with it the foundations of what was to become modern neuroanatomical science. Paradoxically, the two awardees had been led by their researches to diametrically opposed views of the organization of the nervous system. Golgi believed in a continuous network of axons that formed the basis of all the integrative properties of the nervous system, while Cajal had provided the information that led to the formulation of the neuron doctrine that saw the nervous system as being made up of chains of discontinuous cells joined by polarized functional contacts that we now call synapses. The paper takes the form of an interview with Professor Cajal in the Grand Hotel Stockholm. His responses to questions posed by the imaginary interviewer are all taken from Cajal's own writings.     

Vision and the dimensions of nerve fibers

Vision provided the obvious source of determining the dimensions of nerve fibers when suitable achromatic microscopes were directed at neural tissue in the 1830s. The earlier microscopes of Hooke and Leeuwenhoek were unable to resolve such small structures adequately. However, it was not Hooke's microscope that led to an estimate of the dimensions of nerve fibers, but his experiments on the limits of visual resolution; he determined that a separation of one minute of arc was the minimum that could normally be seen. Descartes had earlier speculated that the retina consisted of the ends of fibers of the optic nerve, and that their size defined the limits of what could be seen. Estimates of the diameters of nerve fibers were made on the basis of human visual acuity by Porterfield in 1738; he calculated the diameters of nerve fibers in the retina as one 7,200th part of an inch (0.0035 mm), based on the resolution of one minute as the minimum visible. In the same year, Jurin questioned the reliability of such estimates because of variations in visual resolution with different stimuli.     

以心为本:天性与良知的对话

稻盛和夫的经营哲学主要是由“敬天爱人”与“以心为本”、“利他经营”构架而成。关于“敬天爱人”在另文已有论述,本文拟就“以心为本”与“利他经营”做一阐析。“以心为本”、“利他经营”是稻盛经营哲学的重要组成部分,也是稻盛和夫在40余年的经营实践中始终不渝地加以贯彻、实行的基本原则。如果把稻盛的经营哲学比作飞行器的话,那么“敬天爱人”就相当于它的导航系统,而“以心为本”、“利他经营”则是它的推进器。在稻盛的整个经营活动当中,“敬天爱人”总是能出人意料地发现常人难以发现的目标,而“以心为本”、“利他经营”又总是能令人称奇地将其送至别人无法接近的目标。其结果使稻盛的经营创造出一个又一个的奇迹,跃上一个又一个的台阶,直至步入世界的殿堂。     

Vision and the Dimensions of Nerve Fibers

Vision provided the obvious source of determining the dimensions of nerve fibers when suitable achromatic microscopes were directed at neural tissue in the 1830s. The earlier microscopes of Hooke and Leeuwenhoek were unable to resolve such small structures adequately. However, it was not Hooke’s microscope that led to an estimate of the dimensions of nerve fibers, but his experiments on the limits of visual resolution; he determined that a separation of one minute of arc was the minimum that could normally be seen. Descartes had earlier speculated that the retina consisted of the ends of fibers of the optic nerve, and that their size defined the limits of what could be seen. Estimates of the diameters of nerve fibers were made on the basis of human visual acuity by Porterfield in 1738; he calculated the diameters of nerve fibers in the retina as one 7,200^th part of an inch (0.0035 mm), based on the resolution of one minute as the minimum visible. In the same year, Jurin questioned the reliability of such estimates because of variations in visual resolution with different stimuli.     

Hallucinations and pathological visual perceptions in Maupassant's fantastical short stories--a neurological approach

Maupassant excelled as a realist writer of the nineteenth century, with fantastical short stories being an outstanding example of his literary genius. We have analysed four of his fantastical stories from a neurological point of view. In "Le Horla," his masterpiece, we have found nightmares, sleep paralysis, a hemianopic pattern of loss and recovery of vision, and palinopsia. In "Qui sait" and in "La main" there is also an illusory movement of the objects in the visual field, although in a dreamlike complex pattern. In "Lui," autoscopy and hypnagogic hallucinations emerge as fantastical key elements. The writer suffered from severe migraine and neurosyphilis involving the optic nerve, which led to his death by general paralysis of the insane (GPI). Visual loss and visual hallucinations affected the author in his last years, before a delirant state confined him to a nursing home. Our original hypothesis, which stated that he could have translated his sensorial experiences coming from this source to his works, had to be revised by analyzing some of his earliest works, notably "Le Docteur Héraclius Gloss" and "La main d'écorché" (1875). We found hallucinatory symptoms, adopting the form of autoscopy and other elaborated visual misperceptions, in stories written at age 25, when Maupassant was allegedly healthy. Therefore, we hypothesize that they may be related to his hypersensitive disposition, assuming that no pathology is necessary to experience such vivid experiences. In addition, Maupassant's abuse of drugs, as illustrated in "Rêves," could have provided an additional element to outline his painstaking visual depictions. All these factors, in addition to his up-to-date neurological knowledge and attendance at Charcot's lectures at "La Salpêtrière," armed the author for repetitive and enriched hallucinatory experiences, which were transferred relentlessly into his works from the beginning of his career.     

The Evolution of the Terminology of the Basal Ganglia,or are they Nuclei?

Basal ganglia have been generally used to refer to some subcortical nuclei. However, it is a misnomer since ganglion is a group of nerve cells especially located outside of the brain or spinal cord. We evaluated the terminology of the basal ganglia from historical and terminological points of view.     

The evolution of the terminology of the basal ganglia, or are they nuclei?

Basal ganglia have been generally used to refer to some subcortical nuclei. However, it is a misnomer since ganglion is a group of nerve cells especially located outside of the brain or spinal cord. We evaluated the terminology of the basal ganglia from historical and terminological points of view.     

The Sherrington–Cushing connection: A bench to bedside collaboration at the dawn of the twentieth century

ABSTRACT

British physiologist Charles Sherrington (1857–1952) and American neurosurgeon Harvey Cushing (1869–1939) were seminal figures in the history of neuroscience. The two came from different worlds, one laboratory-based and the other largely clinical. Their scientific intersection, beginning in July 1901, provides a glimpse into a nascent form of “bench to bedside” collaboration, which carried with it the potential to extend the arm of neurophysiological experimentation from Sherrington’s laboratory to Cushing’s operatory. I reviewed extensive primary source materials archived at Yale University School of Medicine Library. Sherrington viewed Cushing’s bedside work as an opportunity, in humans, to extend his bench-side physiological observations on higher primates, at times almost directing Cushing in the clinic. Cushing would indeed take Sherrington’s observations on apes and extend them to his patients, and the work would eventually overturn the prevailing notion that the motor and sensory cortex were intermixed across the Rolandic fissure.     

Postlesion Recovery of Motor and Sensory Cortex in the Early Twentieth Century

This article addresses early work on partial recovery that followed small motor cortical lesions. Leyton and Sherrington (1917 Leyton, ASF and Sherrington, CS. 1917. Observations on the excitable cortex of the chimpanzee, orang-utan and gorilla. Q J Exp Physiol, 11: 135–222.  [Google Scholar]) studied the motor cortex in apes, hoping to learn more about the contralateral muscle representations. Then they placed small lesions within the precentral cortex, followed by a loss of the contralateral muscle twitches. The sudden loss remained for about one week, but recovery was observed and continued for weeks, up to a standstill. Sherrington and Graham Brown (1913) Graham Brown, T and Sherrington, CS. 1913. Note on the functions of the cortex cerebri. J Physiol (Lond), 46: xxii [Google Scholar] observed the same results in a serial, chronic experiment on a chimpanzee. The brain was sent to Monakow's Brain-Institute in Zurich for investigating the lesions and the degeneration pattern. Constantin von Monakow (1853–1930) had been a pioneer on recovery after acute lesions, coining the term “diaschisis.” During WWI, Graham Brown and Stewart (1916) Graham Brown, T and Stewart, RM. 1916. On disturbances of the localization and discrimination of sensations in cases of cerebral lesions, and on the possibility of recovery of these functions after a process of training. Brain, 39: 348–454. [Crossref] , [Google Scholar] studied a soldier in a British army hospital who suffered from a cerebral gunshot wound, localized in the sensorimotor cortex. Early and prolonged rehabilitation was successful. In 1950, Glees (1909–1999) and Cole (Oxford) placed a small motor-cortical lesion in macaque monkeys; for a few days, the monkeys had difficulties and were slow for the task. Daily training was resumed and recovery was accelerated by alimentary reward. Finally, Lashley (1890–1958) understood that handicapped patients “achieved their goal with variable means.” This demonstrated the value of active and prolonged rehabilitation, in addition to the (passive) recovery of function.     

Feud and Fable: The Sherrington-Horsley Polemic and the Delayed Publication

In the February and March 1894 pages of The Lancet and in private letters, Charles Sherrington and Victor Horsley exchanged angry accusations pertaining to primacy of research on the course of the pyramidal fiber tract as determined from studies in monkeys. The polemics appear not to have ended in a manner satisfactory to either one. Moreover, the dispute allegedly led to a remarkable delay in publication of one of Sherrington’s major contributions, which pertained to the localization of the motor cortex in apes that was published in 1917. Here we examine the argument in detail including the comments of an intermediary, Professor Rubert Boyce. We also examine the evidence for the supposed delay in publication, and conclude that the account of the delay originated in John Fulton’s 1952 obituary of Sherrington, and is not true. We suggest it has become a fable that should no longer be repeated.     

Camillo Golgi's scientific biography

Born in Corteno, a tiny village in the province of Brescia, Camillo Golgi studied at the University of Pavia where he graduated in medicine in 1865 under the guidance of the psychiatrist Cesare Lombroso who sparked his vocation to study the brain. Golgi then began to learn histological techniques under the direction of the pathologist Giulio Bizzozero. In 1872 he moved to Abbiategrasso as chief of a hospital for chronic diseases. In a rudimentary laboratory he developed the silver-bichromate staining technique, the 'black reaction', which was a breakthrough for nervous tissue structure research. While in Abbiategrasso Golgi demonstrated the branching of the axons, and observed striatal and cortical lesions in a case of chorea. He returned to Pavia as Professor of Histology and General Pathology, and made a series of important discoveries that still bear his name: the Golgi tendon organ, the Golgi-Mazzoni corpuscles, another Golgi method to stain nerve cells based on the use of potassium dichromate and mercuric chloride, the canaliculi of the parietal cells of the gastric glands (Muller-Golgi tubules), the Golgi-Rezzonico myelin's annular apparatus (or Golgi-Rezzonico horny funnels), the cycle of malarian parasites (Golgi cycle), the relationship between recurrent malarian fever bouts and the multiplication of the Plasmodium in the blood (Golgi law), the relationship between the vascular pole of the Malpighian glomerulus and the distal tubule, the Golgi's pericellular nets and finally, and most importantly, the cytoplasmic 'internal reticular apparatus' (Golgi apparatus). In 1906 Golgi was awarded the Nobel prize for Medicine or Physiology. He died in Pavia on 21 January 1921.     

The unbearable lightness of the extrapyramidal system

The concept of the extrapyramidal system comprises an amalgam of disparate and often conflicting ideas with a tortuous history. To the theoretical neuroscientist or practicing clinician, it promptly evokes semantic associations that are hardly reminiscent of its original meaning. The purpose of this article is to revisit the sources of the extrapyramidal concept and to examine the transformations that it went through from its inception, in the late 1890s, up to the neuroimaging revolution of the 1980s. Our review shows that the use of "extrapyramidal" as a surrogate for the basal ganglia, disorders of movement, or certain manifestations of spastic hemiplegia does not apply to humans; rather, it represents the historical product of the unwarranted translation of results of animal experimentation into the interpretation of clinical findings on human patients, misguided clinico-anatomic deductions, and fanciful phylogenetic notions. We conclude that the extrapyramidal concept is a valid and robust anatomic concept as long as it strictly refers to the collection of descending fibers originating in a few discrete brainstem tegmental motor nuclei that project to the spinal cord.