SDT - Electrophysiology

Utrecht - Science

Electrophysiology - Professionals on the Shop Floor

BEFORE AND AFTER WW II

Dijkgraaf's appointment as professor of Comparative Physiology in 1948 meant a change of research topics. Whereas his predecessor Jordan studied the physiology of muscle and nerve in gastropod feet, Dijkgraaf favoured senses-and-behaviour of aquatic animals. The string galvanometer, induction coils, and kymographs were replaced by electronic equipment. Nevertheless it would take many years before a full change to electronics had taken place. This was due in part to the mismatch between commercially available equipment and the demands of physiological research. On the other hand lack of appropriate lab space, increasing student numbers, and unpredictable university management played their parts as well

Image left: kymograph with sooted drum, induction coil, and the famous Lucas 'swing spring' for double pulse stimulation of nerve and muscle tissue to determine refractory periods. The kymograph was used on physiology practicals till the end of the sixties of the last century.

1963 KALMINIUM - EXPANSION UNDER AD J. KALMIJN

After WW II, in 1947, the electrophysiologist B.J. Krijgsman published an enthustiastic treatise on the use of the Philips electron beam oscillograph in physiology research. Unfortunately, he left for South Africa in 1950, which did not help Dijkgraaf's efforts to develop instruction of electrophysiological methods. Peter E.P.Goerner's arrival at Utrecht caused a revival, which was continued and boosted by PhD student Ad J. Kalmijn from 1963 on. There were ample means to invest in equipment, and even possibilities to attract personnel. The only handicap was a serious lack of lab space. Kalmijn received electronic assistance from A.A.C.(Cor) Schoenhage, and analytical support from W.J.G (Wim) Loos, for his investigation of the function of the Lorenzinian ampullae in dogfish, and to implement electrophysiological teaching. After Kalmijn's departure for the U.S.A. in 1970, Schoenhage and Loos would, together with Rob C. Peters and Franklin Bretschneider, continue Kalmijn's work till the first decennium of the 21st century.

Image left top: Copy of a picture from Krijgsman's paper, in which he advocates the use of the Philips electron beam oscillograph.
Ref.: Krijgsman-BJ 1947. Physiologisch onderzoek met den electronenstraaloscillograaf. N.V. Philips, Eindhoven.

Image lower left: Part of a picture from the PhD thesis of professor Ziad Qutob, with left the Tektronix 502 oscilloscope on which a Philips-Voigtlander oscilloscope camera (type FE-106) is mounted, mid front a Philips oscilloscope (Philips GM 3156) with a speaker, and in between a home made pre-amplifier with devices for swim bladder research. The other devices on this picture are not described. Ref.: Qutob-Z 1962. PhD Thesis - Utrecht. The swimbladder of fishes as a pressure receptor (zie ook: Arch. NÃ©erl. Zool. 15, 1-67}.

1968 PHILBRICKIUM - FROM ELECTRON TUBE TO PHILBRICK'S OPERATIONAL AMPLIFIER

Teaching electrophysiological techniques received a major update in 1968. A tour along various hospitable laboratories demonstrated the latest instrumental trends. Battery operated apparatus seemed preferable. Integrated circuits allowed custom made devices, like the voltage-to-current transducer for precision stimulation of electrosensitive fish, and a portable fm-modulator for the recording of dc signals on tape recorders. Such home made devices made recordings in the free field possible. In addition the support of the mechanics and electronics workshop was indispensable. The above mentioned broad expertise of Cor Schoenhage and Wim Loos should not be overlooked.

Image left top: Equipment from the electron tube era. A Tektronix 502A oscilloscope on the lower shelf left, to the right a Revox tape recorder for data storage, and more to the right a Hellige Helgoscript paper recorder. On the upper shelf a Tektronix 160 series for the quantification of ECG-intervals, and the pre-amplifiers of the Hellige recorder. The experimenter is Jelle Atema (1966).
Image left bottom: Circuit of a Voltage-to-Current Transducer from the Philbrick manual, using an operational amplifier, and typical for the custon made devices after 1968.
Ref: Philbrick/Nexus Research, a Teledyne Company 1968, Dedham Mass 02026 USA. Applications Manual for operational amplifiers for modelling, measuring, manipulating & much else (see also: PhilbrickArchive.org).

Image left bottom: Circuit of a Voltage-to-Current Transducer from the Philbrick manual, using an operational amplifier, and typical for the custom made devices after 1968.
Ref: Philbrick/Nexus Research, a Teledyne Company 1968, Dedham Mass 02026 USA. Applications Manual for operational amplifiers for modelling, measuring, manipulating & much else (see also: PhilbrickArchive.org).

1968 AND AFTERWARDS - TRANSISTORS - BATTERY POWERED EQUIPMENT - EXAMPLES OF CUSTOM MADE APPARATUS

The PhD projects on the function of the ampullary organs in the integument of dogfish and catfish consisted of three main questions, von Uexkuell's Trinity:

To which environmental stimuli do the sense organs respond?
Do such stimuli actually occur in the natural environment?
What is the role of such stimuli in survival?

These questions asked for different instrumental approaches. At first commercially apparatus was used; later more and more custom made devices were built by the workshops and by the students themselves. Eventually equipment was built for recording and stimulating micro-ampullary organs in the skin of freshwater catfish. These micro-ampullary organs proved ideal for elementary neurophysiological instruction. It proved possible to record information transport by single neurons in sedated, but otherwise fully intact, catfish. Even students without any micro-surgical experience were able to perform these recordings. The micro-ampullary sensory synapse was demonstrated to be of the glutamatergic type, and could very well function as a model for the synaptic contacts in the human brain. This science paradigm was closed in 2007.

The images hereafter represent a selection of devices and circuits that were designed specifically for research of the electric sense in catfish and dogfish. Last but no least the contribution of Cor Schoenhage should be mentioned, who built many of the opamp modules, amplifiers, plug-in cards etc. Quite a number of these items were transferred to the Utrecht University Museum.

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electronic components, Kalminium	shielded power cable, Kalminium	sustainable signal cables, Kalminium
PAR 113B pre-amplifier, mains/batteries modifications: precision DC, indicator LED mains	Tektronix 212 oscilloscope, mains/batteries	Wavetek 112B function generator, mains/batteries
Uher stereo report 4400, mains/batteries	electric fiels measurement, canal Hoofddijk	custom made amplifier fm-modulator speaker
rotor aquatic DC probe 1972, J. Comp. Physiol. 81, 345-362	marine DC probe 1982, Neth. J. Zool. 32(4), 479-494	marine DC probe, orientation sensor 1982, Neth. J. Zool. 32(4), 479-494
in situ, in vivo implantation of electrodes 1972, J. Comp. Physiol. 79, 29-38	Rob Buwalda's Masterpiece: 3 implants 1972, J. Comp. Physiol. 79, 29-38	electro-orientation test with catfish 1974, J. Comp. Physiol. 92, 273-280
in vivo, in situ single unit recording J. Biol. Education 22(1), 61-66	Huub Gallé's tungsten micro-electrode J. Biol. Education 22(1), 61-66	pre-amplifier for single unit recordings J. Biol. Education 22(1), 61-66
rack with power supply and opamp modules	opamp modules, stock	opamp module with plug-in card
universal pre-amplifier, 1st stage, buffer	universal pre-amplifier, 2nd stage, filters	various plug-in cards for opamp modules
wiring multiplier plug-in card	wiring Schmitt-trigger plug-in card	wiring photosensor plug-in card
plug-in card - amplifier	plug-in card - threshold circuit	plug-incard - current source
LED wirh light guide	pre-amplifiers for practical	plug-in card - frequency modulator
dummy RC-load	current source for electrosensitive fish	amplifier, flter, fm-modulator for field work
1986: preparing a practical, old Lab Wim J.G.Loos, analyst J. Biol. Education 22(1), 61-66	1989: electroreceptor thermal sensitivity Dr. Klaus Schaefer Eur. J. Physiol. 417(1), 100-111	2006: electroreceptor spike patterns Dr. M.J.M.Lankheet PLoS One, 7(3). ISSN 1932-6203
cover booklet wiring diagrams A.A.C. (Cor) Schönhage omnia fecit	wiring diagam opamp modules A.A.C. (Cor) Schönhage omnia fecit	wiring diagram current source A.A.C. (Cor) Schönhage omnia fecit
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Cultural Heritage

Utrecht - Science

Electrophysiology - Professionals on the Shop Floor