Brain Function: Cortical Excitability and Steady Potentials; Relations of Basic Research to Space Biology

By Mary A. B. Brazier

This title is part of UC Press's Voices Revived program, which commemorates University of California Press’s mission to seek out and cultivate the brightest minds and give them voice, reach, and impact. Drawing on a backlist dating to 1893, Voices Revived makes high-quality, peer-reviewed scholarship accessible once again using print-on-demand technology. This title was originally published in 1963.
This title is part of UC Press's Voices Revived program, which commemorates University of California Press’s mission to seek out and cultivate the brightest minds and give them voice, reach, and impact. Drawing on a backlist dating to 1893, Voices Revived

• Language: English
• Publisher: University of California Press
• Release date: Dec 22, 2023
• ISBN: 9780520310605

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BRAIN

FUNCTION

CORTICAL EXCITABILITY AND STEADY POTENTIALS

RELATIONS OF BASIC RESEARCH TO SPACE BIOLOGY

ADOLF BECK

1863-1942

In rectorial robes, wearing the ring given him in honor of forty years of service

to the University of Jan Kasimir in Lvov (Poland), and holding the book he

wrote with Cybulski on The Physiology of Man.

UCLA FORUM IN MEDICAL SCIENCES

NUMBER 1

BRAIN

FUNCTION

Proceedings of the First Conference, 1961

CORTICAL EXCITABILITY AND STEADY POTENTIALS

RELATIONS OF BASIC RESEARCH TO SPACE BIOLOGY

Sponsored by the Brain Research Institute, University of California, Los Angeles,

in collaboration with the American Institute of Biological Sciences

and with the support of the U.S. Air Force Systems Command

EDITOR

MARY A. B. BRAZIER

UNIVERSITY OF CALIFORNIA PRESS

BERKELEY AND LOS ANGELES

1963

CITATION FORM

Brazier, M. A. B. (Ed.), Brain Function, Vol. I:

Cortical Excitability and Steady Potentials;

Relations of Basic Research to Space Biology.

UCLA Forum Med. Sci. No. 1, Univ, of Calif.

Press, Los Angeles, 1963.

University of California Press

Berkeley and Los Angeles, California

Cambridge University Press

London, England

Library of Congress Catalog Card Number: 64-22268

Printed in the United States of America

PARTICIPANTS IN THE CONFERENCE

H. W. MAGOUN, Co-Chairman

Brain Research Institute, University of California Medical Center

Los Angeles 24, California

F. FREMONT-SMITH, Co-Chairman

American Institute of Biological Sciences

Time and Life Building, Rockefeller Center

New York 20, New York

M. A. B. BRAZIER, Editor

Brain Research Institute, University of California Medical Center

Los Angeles 24, California

W. R. ADEY

Space Biology Laboratory, Brain Research Institute

University of California Medical Center

Los Angeles 24, California

J. A. V. BATES

The National Hospital, Queen Square

London, W. C. 1, England

J. M. BROOKHART

Department of Physiology, University of Oregon Medical School

Portland 1, Oregon

N. BUCHWALD

Brain Research Institute, University of California Medical Center

Los Angeles 24, California

T. H. BULLOCK

Department of Zoology, University of California

Los Angeles 24, California

H. CASPERS

Physiologisches Institut der Universität Münster

Münster (Westf.), Germany

M. R. DE LUCCHI

1

U. S. Air Force, Space Systems Division

Inglewood, California

E. DE ROBERTIS

Instituto de Anatomía General y Embriología, Universidad Nacional

Buenos Aires, Argentina

E. EIELBERG

Barrow Neurological Institute

Phoenix, Arizona

J. D. FRENCH

Brain Research Institute, University of California Medical Center

Los Angeles 24, California

S. GOLDRING

Division of Neurosurgery, Washington University School of Medicine

St. Louis 10, Missouri

B. GRAFSTEINt

Department of Physiology, McGill University

Montreal 2, Canada

R. J. GUMNIT

Department of Neurology, State University of Iowa Hospitals

Iowa City, Iowa

W. HAYMAKER

National Aeronautics and Space Administration, Ames Research Center

Moffett Field, California

J. P. HENRY

Department of Physiology, University of Southern California School of Medicine

Los Angeles 7, California

A. A. P. LEÃO

Instituto de Biofísica, Universidade do Brasil

Rio de Janeiro, Brasil

R. B. LIVINGSTON

Laboratory of Neurobiology, National Institutes of Health

Bethesda 14, Maryland

1 CURRENTLY ASSIGNED TO THE BRAIN RESEARCH INSTITUTE, UNIVERSITY OF CALIFORNIA, LOS ANGELES, F PRESENT ADDRESS: ROCKEFELLER INSTITUTE

NEW YORK 21, N.Y.

S. LUSE

Department of Anatomy, Washington University School of Medicine

St. Louis 10, Missouri

H. MCILWAIN

The Maudsley Hospital, Denmark Hill

London, S.E. 5, England

F. MORRELL

Division of Neurology, Stanford Medical Center

Palo Alto, California

D. P. PURPURA

Department of Neurological Surgery

Columbia University College of Physicians and Surgeons

New York 32, New York

O. E. REYNOLDS

National Aeronautics and Space Administration

Federal Office Building 6

Washington 25, D.C.

V. ROWLAND

Department of Psychiatry, School of Medicine

Western Reserve University

Cleveland, Ohio

V. S. RUSINOV

1

Institute of Higher Nervous Activity, Academy of Sciences of the USSR

Moscow, USSR

A. VAN HARREVELD

Department of Biology, California Institute of Technology

Pasadena, California

A. A. WARD, JR.

Department of Neurosurgery, School of Medicine

University of Washington

Seattle, Washington

1 NOT PRESENT.

UCLA FORUM IN MEDICAL SCIENCES

EDITORIAL STAFF

VICTOR E. HALL, Editor

MARTHA BASCOPE-V ARGAS, Assistant Editor

EDITORIAL BOARD

Forrest H. Adams Mary A. B. Brazier Louise L. Darling Morton I. Grossman John S. Lawrence

William P. Longmire

H. W. Magoun Sidney Roberts Emil L. Smith Reidar F. Sognnaes

UNIVERSITY OF CALIFORNIA, LOS ANGELES

UCLA FORUM IN MEDICAL SCIENCES

A Preface to the Series

When recently in Los Angeles as a Visiting Professor, Dr. Jan Waldenström observed the irony of one of the pendular swings in the history of science. In medieval times, he pointed out, scientific publications were so few that interested scholars could learn of foreign accomplishments chiefly through personal visits. Now the vast number of burgeoning journals is sometimes a formidable barrier between the inquirer and the exposed heart of a large problem—thus does ultra-modernity lead to medieval methods of learning!

Whether for medieval or modern reasons, the visits of those who bring a point of view, a provocative question and, above all, an answer, are invigorating and welcome occasions. Sometimes convergent visits, planned as symposia, seem to organize, if only temporarily, and therefore challengingly, a shifting assortment of facts and ideas otherwise difficult to hold in focus.

The editing and publication of such meetings which are periodically held at UCLA seemed to us to be one small part of an answer to a large need accentuated by the information explosion. This need was described by President Kennedy’s Science Advisory Committee in a report entitled Science, Government, and Information and editorially pin-pointed in Science as follows: One recommendation which could be implemented is that some scientists and engineers ‘commit themselves deeply to the job of sifting, reviewing, and synthesizing information’ since ‘reviewing, writing books, criticizing, and synthesizing are as much a part of science as is traditional research.’

Out of these considerations, and with this initial volume, the UCLA Forum in Medical Sciences has been created, to review, to synthesize and to analyze rather than to serve as another outlet for original papers. The Forum will be published irregularly as the spirit moves the Editorial Board and as those from our own school and from afar gather under its aegis for discussion.

The topics will vary widely from the deep roots of medicine in biology, chemistry and physics to the applied medical arts. It is our hope that each volume, whatever its subject, will in its sphere provide that broad view which stands between atomistic surfeit on the one hand and a formless void on the other.

Even more we hope that the Forum will reflect among participants, auditors and readers alike, a certain warmth felt by those whose labors are related by content and aspiration to works in distant lands and, indeed, related to life itself.

SHERMAN M. MELLINKOFF

Dean, UCLA School of Medicine

NOTE

The conference, the proceedings of which occupy this volume, is the first of a series supported by grants made to Dr. H. W. Magoun of the Brain Research Institute of the University of California, Los Angeles, by the United States Air Force Systems Command. The American Institute of Biological Sciences acted as co-sponsor.

The second conference of the series, held in November 1962, was on the subject of RNA and Brain Function. The third one (November 1963) dealt with Speech, Language and Communication.

VICTOR E. HALL Forum Editor

PREFACE

Magoun: In an age in which man is going into space, his brain will encounter stresses whose effects are, as yet, little known. Imperative for an understanding of how his brain will meet these new experiences is a fundamental study of its most basic reactions.

In each of this series of conferences it is proposed to focus on some facet of the brains function which needs elucidation in this context. Clearly cortical excitability is one of the most important of the factors that deserves understanding in a situation in which man must maintain performance capability in an alien environment. This can be studied in many ways; this first conference will explore a possible sign of cortical excitability that has received less consideration than many others, namely a steady potential change that can be recorded between the cortical surface and indifferent structures. Recent study has led some observers to regard this electrical sign as indeed a potent indicator of cortical excitability. The shift to negativity in alerting situations, such as alarm, awakening, orienting reactions or peripheral stimulation, stands out in strong contrast to the positive shift that is seen in sleep or anesthesia or tranquilization with chlorpromazine.

What these shifts mean in terms of intimate mechanisms such as ion transport, transmitter substances, membrane changes or other fine grain processes, necessitates, among other things, an understanding of the microstructure and microchemistry of the brain. A synthesis of this magnitude cannot be managed in one conference, but hopefully the presentations to follow will form a first approach to this goal.

I now introduce Colonel James Henry of the Space Task Group at Langley Field, in charge of the animal phase of the Mercury Project.

Henry: D.C. potential shifts are an expression of some change, perhaps in the set and physiology of the brain stem. If for example you recognize, with Dr. Caspers, the significance of D.C. shifts in the relationships between sleep and wakefulness and if, as Dr. Adey points out, we can relate tissue impedance to D.C. changes, and to other associated physiological changes, then we can see that the central question of man’s role in space missions, that of the over-all competence of performance of the brain, may be very closely related to the subject of the present conference.

The question as to how classical basic neurological and behavioral research can relate to space science is not usually taken seriously enough. So I would just like to say a few words on the general philosophy of the relationship between biology and flight.

In the past, biologists have helped engineers with the hardware that they designed to fly within the atmosphere, and with the so-called aviation medicine problems resulting from such flight. Concern has been with flight in the atmosphere, with the gradual loss of its blanketing effects, with the loss xiii of gas pressure, of oxygen tension, and with the accelerations that are induced when turns are made at high speeds.

Classical aviation medicine has also involved work on physiological psychology. It has been concerned with vestibular disorientation and, of course, with selection with regard to aptitudes for flight and with man-machine adaptation. But there is a critical difference between the aviation medicine of the past and the space medicine or space biology that we are now facing. In aviation, exposures were always within the earth’s atmospheric blanket, and they have always been of limited duration. The men did not have to maintain the machines in flight. The maximum period of any single flight exposure has been a matter of hours. In the future, we are going to be faced with progressively increasing durations of exposure. Men will have to make the same shift that was made with regard to transoceanic traveling as compared to the early voyaging, when the navigators kept in sight of land and drew up their ships in the evenings and maintained them on the shore. It will be necessary to maintain the vehicles in flight. This imposes stringent new requirements on the skill and versatility of the occupants of such vehicles. Further new conditions in space flight are the absence of gravitational effects, the so-called weightlessness, and the radiation that constitutes such a potential hazard.

In space flight as in aviation we are required to do research, not merely in these new areas, but in selection, from the point of view of the motivation and skill needed to handle extremely complex situations for prolonged periods in the face of a threatening environment. The ultimate basis of such selection rests on better understanding of the functioning of the central nervous system. Men will certainly be pushed to the limit in the competition to achieve the missions and goals they set themselves.

We have then today to face the question of weightlessness and possible disorientation, and the problem of adaptation of the individual to it. This is, perhaps, the one that concerns us most at the moment. It is always possible that, in practice, adaptation to this situation may develop in the same way as to the motions encountered in oceanic voyages. But even if the matter of weightlessness is satisfactorily settled there will always be the question of developing individuals who will give the highest level of performance in spite of very great demands for prolonged periods. This, in turn, is really a problem which has long been the concern of society. To this extent then the requirements for space crew members do not differ from those for any other exacting profession. We are concerned in fact with methods of determining and improving long-term motivation: with investigating, for example, the possible effects of early experience upon motivation; the problem of improving methods of training, and of conditioning individuals. This training does not solely involve enduring environmental effects, such as labyrinthine stimuli. It involves the whole question of optimum response in the manmachine situation.

There is concern too, with the mechanisms underlying diurnal rhythms xiv and sleep-wakefulness cycles, because it is possible that the space environment may disturb these rhythms. In addition, the demands of the task may be such that it may not always be possible to adjust the work to rhythms as they exist in a terrestrial environment.

Finally, the question comes up of controlling responses to the stress of long-term isolation, and to other threats. Contributions to this problem can be expected as a result of the application of the techniques of neurophysiological investigation.

So, to summarize, the major role of the neurological sciences in space biology is one of defining the mechanisms underlying the adaptation of the individual to a complex man-machine relationship. It is not feasible to provide biological protection for the individual in the form of increased tolerance for the physical stresses of space. The individual can be protected from the environment by the engineering of his capsule, but he will still have tremendous demands made on him within the machine. He will be required to perform as a vital part of the complex instrumentation-computer assembly, and to maintain his performance for prolonged periods in an environment which, while it may not present any remarkable physical stresses, will surely impose very considerable psychological strains.

Makoun: I might add that, while the engineers are going to take care of the hardware, and the astronauts are going to be the pioneers who do the traveling, the responsibility for working out, in any fundamental way, the brain mechanisms that form the basic substratum of performance, lies with the scientists who study the brain. Their contributions should be of great significance and relevance, and it is with the purpose of encouraging these contributions that these conferences are designed.

Fremont-Smith: On behalf of the American Institute of Biological Sciences, I am very happy to welcome all of you to this conference.

The American Institute of Biological Sciences has, among its many activities, a program of developing better interdisciplinary communication, and is therefore pleased to have the privilege of co-sponsoring this conference.

CONTENTS 1

CONTENTS 1

HISTORICAL INTRODUCTION THE DISCOVERERS OF THE STEADY POTENTIALS OF THE BRAIN: CATON AND BECK

ULTRASTRUCTURE AND CHEMICAL ORGANIZATION OF SYNAPSES IN THE CENTRAL NERVOUS SYSTEM

METABOLIC AND ELECTRICAL MEASUREMENTS WITH ISOLATED CEREBRAL TISSUES: THEIR CONTRIBUTION TO STUDY OF THE ACTION OF DRUGS ON CORTICAL EXCITABILITY††

ON THE SPREAD OF SPREADING DEPRESSION*

NEURONAL RELEASE OF POTASSIUM DURING SPREADING DEPRESSION***

STUDIES ON LEARNING

I. EFFECT OF TRANSCORTICAL POLARIZING CURRENTS****

II. STEADY POTENTIAL SHIFTS IN CORTEX

III. DISCUSSION

RELATIONS OF STEADY POTENTIAL SHIFTS IN THE CORTEX TO THE WAKEFULNESS-SLEEP SPECTRUM

NEGATIVE STEADY POTENTIAL SHIFTS WHICH LEAD TO SEIZURE DISCHARGE’

THE UNIDIRECTIONAL POTENTIAL CHANGES IN PETIT MAL EPILEPSY

REVIEW AND CRITIQUE

PART II ASPECTS OF BRAIN PHYSIOLOGY IN THE SPACE ENVIRONMENT

STUDIES OF BRAINS EXPOSED TO COSMIC RAYS AND TO ACCELERATED ALPHA PARTICLES

RELATIONS OF BASIC RESEARCH TO SPACE SCIENCE

INDEXES

INDEX OF SUBJECTS

INDEX OF NAMES

HISTORICAL INTRODUCTION

THE DISCOVERERS OF THE STEADY POTENTIALS

OF THE BRAIN: CATON AND BECK

MARY A. B. BRAZIER

Brain Research Institute

University of California

Los Angeles

The major theme of the conference reported in this volume was the possible relationship of level of cortical excitability to shifts in the steady potential difference that can be recorded between cortical surface and indifferent structures. The existence of this steady potential has been known for nearly a century but its relationship to excitability has remained obscure.

In the first part of the last century, even the question whether or not the cortex was in any way excitable was the subject of a major controversy. These early polemics focused on whether the cortex was excitable by externally applied stimuli; the more subtle question (with which this conference deals) as to whether the brain’s internal electrical characteristics reflected its state of excitability came later.

The attempts to explore the effects on the cortex of external stimuli had begun in the 18th century. Haller, 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 (15).

The Italian physiologists had been more successful. The Abbé Fontana and Caldani (Galvani’s predecessor in the chair of anatomy at Bologna) had convulsed their frogs by electrical stimulation inside their brains (13, 4). Rolando, following their lead, extended his experiments to pigs, goats, sheep, dogs and also to birds (18). The influential Magendie, however, had failed and had proclaimed the cortex electrically inexcitable, an opinion in which he was backed by Flourens (12). In those days before the neuron had been recognized as the unit of the nervous system and 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 motor effect, but soon an incontrovertible proof was to be given. For a new technique was to invade the field of brain localization. This was elec-

trical Stimulation. As everyone knows, the pioneers were the two young doctors in Berlin, Fritsch and Hitzig (Figure 1). They demonstrated that certain regions of the cortex were excitable by electricity, as evidenced by elicited movements (14).

They did not have plain sailing, for though Ferrier (Figure 2) followed up (9, 10) and expanded their original finding in his classic book, The Functions of the Brain (11), acceptance even then was far from general. George Henry Lewes, whose name has almost faded from scientific memory, was then a respected authority, for his Physiology of Common Life (16) was the best account of the nervous system available at the time.

Lewes, better remembered for his liaison with George Eliot, wrote a pungent attack (17) both on Ferrier and on the original Fritsch-Hitzig concepts of functional localization. Lewes did not spare his fire. He deplored the increasingly popular but thoroughly unphysiological conception of Localisation. … We should marvel, he wrote, to witness so many eminent investigators cheering each other on in the wild-goose chase of a function localised in a cerebral convolution. Just because stimulation of a cortical area evoked a movement, that did not, in Lewes’ opinion, prove it to be a motor center. We do not, he wrote, consider the centre of laughter to be located in the sole of the foot, because tickling the sole causes laughter.

It was Lewes’ view that the electrical current passed through the grey matter as through any conductor and evoked a movement by exciting the white matter. In support of this view, he quoted the fact that, after removal of the cortex, electrical stimulation of the underlying white substance did indeed provoke movement, presumably via the basal ganglia.

But these were all experiments and controversies concerning the excitability of the cortex to externally applied currents. It is only in 1875, when the brain was found to have electrical properties of its own, that the suggestion that these may have some relationship to cortical excitability is first encountered. The idea came quite independently to two men, one in England and one in Poland, and in each case it derived from their knowledge of peripheral nerve.

In the mid-nineteenth century, physiologists in many countries were focusing their interest on the electrical activity of nerve. The excitement was caused by the realization that the electrical activity of the nervous system could be used as a sign of its excitability. In the eighteen-forties, Du BoisReymond (Figure 3), the great physiologist at Berlin, had finally demonstrated unequivocally that activity in a peripheral nerve was invariably accompanied by an electrical change, a negative variation in the standing potential that had been found between a cut end of the nerve and its longitudinal surface (7, 8). This demonstration was the climax to a long- drawn out struggle to confirm or deny the existence of Galvani’s "Animal

Electricity". Du Bois-Reymond did not underestimate the importance of his demonstration. He said,

If I do not greatly deceive myself I have succeeded in realizing in full actuality (albeit under a slightly different aspect) the hundred years’ dream of physicists and physiologists, to wit, the identification of the nervous principle with electricity (7).

Many workers soon confirmed that activity caused a negative variation in the potential difference between outside and cut surface of peripheral nerve, and in due time the idea came to some workers in distant countries, England, Russia, Poland and Austria, that the passage of sensory impulses in the brain might similarly be detectable by an electrical change.

The first to experiment with this idea was Richard Caton (Figure 4), a young lecturer in physiology at the Royal Infirmary in Liverpool. Following, analogously, the technique used for peripheral nerve, Caton put one recording electrode on the exposed cortex of an animal and the other on a cut surface. For stimulus he used the light from an oxy-hydrogen lamp, for he had no electric light. To his delight he found the change in potential he was looking for, but in addition he found something unexpected: when he had both electrodes on the surface of the cortex or one on the cortex and one on the skull, he found an incessant, though feeble, waxing and waning of current in the absence of all stimulation. This was the discovery of the electroencephalogram.

It was to be many decades before the electroencephalogram would be used to localize brain function, and Caton’s own interest certainly turned more to the phenomenon of the major potential shift that he found on sensory stimulation. In his first brief report, published in the British Medical Journal in 1875 (5), Caton included the following description:

The electric currents of the grey matter appear to have a relation to its function. When any part of the grey matter is in a state of functional activity, its electric current usually exhibits negative variation. For example, on the areas shown by Dr. Ferrier to be related to rotation of the head and to mastication, negative variation of the current was observed to occur whenever those two acts respectively were performed. Impressions through the senses were found to influence the currents of certain areas; e.g., the currents of that part of the rabbit’s brain which Dr. Ferrier has shown to be related to movements of the eyelids, were found to be markedly influenced by stimulation of the opposite retina by light.

In this early report one notices the marked impact of Ferrier’s work and a tendency to expect related localizations for sensory responses and peripheral motor effects. Two years later, however, Caton reported further experiments that gave clearer results (6). Caton summed up his experiments in this second report as follows:

The investigation thus far tends to indicate that the electrical currents of the grey matter have a relation to its function similar to that known to exist in peripheral nerves, and that the study of these currents may prove a means of throwing further light on the functions of the hemispheres.

These findings had little impact on the scientific world; no one followed the lead that Caton had given and, as a consequence, we find the same discovery being made again fifteen years later.

In Poland, a young assistant in the physiology department of the University of Jagiellonski in Krakow, Adolf Beck (Figure 5), not knowing of Caton’s earlier work, was searching initially for the same phenomenon,

namely for electrical signs in the brain of impulses reaching it from the periphery. Like Caton before him, he succeeded, and he too found the brain wave.1 His animals were mostly dogs and rabbits, and he published the protocols of all his experiments in the Polish language as the thesis for his doctorate (1).

As this was a doctoral thesis (Figure 6), we get the experimental procedures and results reported in far more detail than in Caton’s briefer publications in the medical journals. Beck found, as had Caton, that he could evoke a potential swing as a response to light, provided at least one of his electrodes lay on the occipital cortex. In two of the experiments he described, he found a small deviation in response to a shout when one of the electrodes was on the temporal cortex.

An additional observation of Beck’s holds great interest for those familiar with the blocking action of peripheral stimuli on the EEG. This phenom-

Oznaczenie l(kalizacy i

w mózgu i rdzeniu

za pomoca zjawisk clektrycznych.

Napisa

Dr. Adolf Beck,

asystent Zak fad U fizyjologicznego Uniw. Jag w Krakowie.

Figure 6. The title page of Beck’s thesis, in which he

described the steady potentials of the brain and the influ-

ence on them of peripheral stimulation.

enon, confirmed later by many, remained an empirical observation for almost sixty years, until the elucidation of the desynchronizing action on cortical potentials of the ascending reticular system. Beck’s own description reads as follows:

In addition to the increase or decrease in the original deviation during stimulation of the eye with light, rhythmic oscillations that have been previously described disappeared. However, this phenomenon was not the consequence of light stimulation specifically for it appeared with every kind of stimulation of other afferent nerves, t

This is the clearest statement, based on experimental work, that comes to us from the last century of the question being examined in the present volume. In suggesting this theory, Beck relates that he was influenced by the work of Sechenov, the great Russian physiologist (Figure 7), and by reading the account in the medical journal Vrach* of a report presented by Verigo at the Third Congress of Russian Physicians held in St. Petersburg in 1889 (19).

On connecting the hemispheres of the frog with the circuit of the galvanometer, Dr. Verigo obtained a continuous oscillation of the needle that did not lend itself to explanation; however, it was nevertheless possible to be certain that on each

Verigo (Figure 8), a pupil in Sechenov’s laboratory, reported similar changes in demarcation current in the lumbar cord of frogs on stimulation of the leg, and also reported a negative variation in potential of the anterior part of the frog’s brain when its hind legs were moved. The report in Vrach stated, in part, as follows (translated):

* Report of the Third Congress of Russian Physicians, St. Petersburg, 1889. Vrach, 1889, 10: 45.

movement of the legs, the anterior part of the hemisphere became relatively negative, electrically, to the posterior part.

It is interesting to note that, when he had his electrodes on the brain, Verigo was puzzled by the continuous oscillation of the needle that did not lend itself to explanation. This was, of course, the EEG of the animal, though not recognized by him as such. This led Wedensky, who was present, to suggest that this method might be used to delineate localization in the cortex. These suggestions were, in fact, being made fourteen years after Caton had first applied the method successfully, though his work was apparently unknown to Wedensky.

Later in his thesis, Beck returns again to a discussion of this phenomenon and explains it as suppression or blocking.

Beck felt the challenge of his results and of his proposal that the focal shift of the steady potential on specific sensory stimulation signified increased activity in that cortical center. He argued that were this so, a locally produced increase of activity in that center should produce the same potential shift. Consequently, he stimulated the cortex of a dog directly with a weak induction current and obtained a marked deviation.

If my assumption concerning the relationship of the change in action current to the origin of the active state in certain centers is correct, namely that the development of electro-negativity in an area of cortex really indicates the creation of an active state in centers located there, then on direct stimulation of that site an electro-negative swing should result. … This was theoretical reasoning; the experiments proved that it was right. … Since during stimulation of the eye by light there was a positive deviation of 21 mm, and on direct stimulation of the occipital cortex close to the negative electrode there was deviation of 80 mm in the same direction, does this not prove that this same cortical region went into an active state during stimulation by light? I obtained similar results on stimulating the leg and the corresponding part of the cerebral cortex, by which I mean that both gave a deviation in the direction of negativity.

2

Beck at this time had no camera, but he drew many sketches to illustrate the protocols on which he recorded the movements of his galvanometer in numerical units. A page from his thesis illustrating a graph from one of his experiments is reproduced in Figure 9. This illustrates his claim that direct stimulation of a cortical area produces a shift in potential in the same direction as is caused by peripheral stimulation of its afferent supply. In the experiment illustrated, the same recording linkage is used both for stimulation of the visual cortex and of the motor cortex. Hence the galvanometer swings in an opposite direction for increased negativity at the occiput from that for increased negativity at the motor cortex.

In his thesis, Beck says that he was unable to find any reference in the literature, other than the short report of Verigo’s describing a shift of the standing potential in the brain having a relationship to its active state (19).

For measuring these steady potential shifts, what were the techniques used in 1890? Beck describes his (Figure 10) as follows:

To conduct the current away from the cord or brain I used nonpolarising electrodes, as described by Du Bois-Reymond, which I modified a little; they were made from a fine clay saturated with 1% solution of sodium chloride, and set in the form of a suppository on a glass tube filled with a concentrated solution of ZnS (zinc sulfide). The glass tube contained an amalgamated zinc wire and all this was supported on a solid tripod insulated with rubber. One wire from the electrode went direct to the galvanometer, the second wire went to a movable switch of a rheostat, one end of which was connected with the second wire of the galvanometer. Both ends of the rheostat were connected with wires to the Daniel cell for balancing current. Needless to add, by means of keys and commutator the direction of the compensating current could be changed, or the connection interrupted between the electrodes (nonpolarizing) and the galvanometer. Opposite the galvanometer mirror, at a distance of 330 centimeters, was a tele

scope through which a suspended scale was read. The sensitivity of the Wiedemann galvanometer, modified by Hermann, was calculated by the physics assistant of the Jagiellonski University. One centimeter on the scale (when the distance from the galvanometer mirror was equal to 288 centimeters) corresponds to 43/10,000,000 ampères.*

His primary objective was to relate these potential shifts to localization of areas on the central nervous system activated by peripheral stimuli, and in this he was very successful. He used the following formula for expressing the electrical sign of the potential shifts that he found:

I have to explain the numbers given here; the scale is one meter long with the zero point in the middle and 500 millimeters division on each side. The part of the scale situated to the left of person looking in the telescope I consider positive, the other side—negative.!

Using this definition of negativity, the following generalization can be made of his findings in the many experiments he detailed: in all his experiments, he found (before stimulation) the more rostral parts of the nerve axis negative (in his terminology) to the caudal ones. The more rostral parts became even more negative on sciatic stimulation. Beck adopted Sechenov’s term for what we now call the resting potential (as differentiated from the demarcation potential)—he called it the active autonomous current.

Beck found the extent to which the standing potential could be caused to shift by peripheral stimulation, and specifically related this to the excitability of the central nervous system:

I have to agree with Sechenov that the autonomous current and the constancy

* Thesis (1): p. 195-196, translated. In other words, he used an opposing current to balance out the resting potential, for sometimes the resting potential gave a deflection over 500 mm from zero and therefore off his galvanometer scale. For those interested in EEG potentials, he also found these and gives a measurement of 12 mm deflection for them (superimposed on the standing potential).

+ Thesis (1): p. 197, translated.

of occurrence of the negative shift are very changeable, depending upon the excitability of the central nervous system. The difference was striking between the frogs kept in the institute during the winter and fresh, spring frogs; in the former, the deflection caused by the autonomous current was negligible—in the latter, however, one had to use a fairly strong current to compensate for the autonomous current.*

As the conference reported in this volume gives consideration to the effect anesthesia has on the standing potential of the mammalian brain, it is of interest to see what this young Polish scientist reported in 1890. He gives the protocol of experiments on a rabbit and a sketch of his electrode placements (Figure 11). With electrodes on the occipital lobe, his galvanometer gave a deflection (oscillating with the EEG) initially on the positive side of zero by his arbitrary terminology.

I narcotized the animal with chloroform to see what happens to the independent oscillations during narcosis. As soon as I started to give chloroform, the deviation which read 140, changed to the negative side as far as —330, where it began to oscillate, until the narcosis deepened. After the corneal reflex disappeared, the oscillations also ceased. 1

2 Thesis (1): p. 210, translated, f Thesis (1): p. 216, translated.

In attempting to assess the true sign of the change (called negative by Beck’s arbitrary terms), it may be noted that, in this same rabbit, the effect of peripheral stimulation (light, sciatic stimulation) was a change in the opposite direction to that caused by anesthesia.

In another experiment, this time in a large non-curarized dog (Figure 12), chloroform brought the galvanometer reading from 100 mm (plus or minus an EEG oscillation of 10 mm) on the positive side of zero down to 55. Just prior to being given the anesthetic the dog had been tested for the response to sound. A deflection in the opposite direction to that later caused by anesthesia resulted.

In the light of today’s technology it is indeed impressive to find in this doctoral thesis of 1890 a clear description of the EEG; of the blocking effect on the EEG of afferent stimulation by all modalities; of the standing (D.C.) potential, together with the localized changes in it evoked by specific sensory stimuli; and the effect on both these electrical phenomena of anesthesia.

This young man went on to become Poland’s most outstanding physiologist and the co-author with his old Professor, Cybulski, of the standard Polish textbook on the physiology of man (2). Five years after obtaining his doctorate, he was appointed to the Chair of Physiology at the University of Jan Kasimir in Lvov, and there he spent the rest of his life. While still continuing (and publishing) laboratory experiments, Beck rose to be Dean and finally Rector, standing by his University through the years of Poland’s stormy history until the final tragedy overtook him, in the form of Hitler’s program for the extermination of all Jews.

As the Germans closed in on Lvov the danger to Beck increased, for he was Jewish. An old man now, rather than go into hiding he chose to stay in the shelter of the University to which he had given so many years of his life. Just before his eightieth birthday, he became unwell, and while he was in the hospital for an ailment, the Germans came to take him to the extermination camp. Beck’s son, a physician, had supplied all members of the family with capsules of potassium cyanide. Beck took his capsule, and saved himself from the gas chamber.

The memory of this man, as a scientist and a humanist, is honored by his countrymen today, as it was in the years of his service to the University he loved so well. In 1934 he had been presented with a gold signet ring to mark forty years of scientific work and, the following year, his portrait had been painted for the University by Stanislaw Batowski. This portrait, that appears as frontispiece to this volume, and in which he can be seen wearing the ring and holding a copy of the book he wrote with Cybulski, is one of the few material traces of Beck to survive the Occupation. The ring, hidden by his daughter under the floor of her home in Warsaw, was found by her after the war in the ashes of the house, which like the rest of the city had been burned to the ground by the Germans after the unsuccessful Warsaw uprising of 1944. The enamel had turned from red to black, but still legible on the ring are the words: Bene merenti facultas medica, a fitting tribute to a fine scientist.

REFERENCES

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2. BECK, A., and CYBULSKI, N., Fizyologia Czlowieka (The Physiology of Man), 2 vols. Kraków, 1915.

3. BRAZIER, M. A. B., A History of the Electrical Activity of the Brain—The First Half-Century. Pitman, London; Macmillan, New York, 1961.

4. CALDANI, L., Institutiones Physiologicæ et Pathologicæ. Luchtmans, Leyden, 1784.

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physik. Veit, Leipzig, 1877.

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11. , The Functions of the Brain. Smith, Elder, London, 1876.

12. FLOURENS, J. P. M., Recherches Expérimentales sur les Propriétés et les Fonctions de Système Nerveux dans les Animaux Vertébrés. Crevot, Paris, 1824.

13. FONTANA,