History of Thomas RECORDING GmbH
Thomas RECORDING was founded in 1989 by Uwe Thomas, and is the sole manufacturer and distributor of the complete range of equipment utilized for the Reitboeck and Eckhorn methods of multiple microelectrode recordings in the brain. These systems were developed in close cooperation with the department of Applied Physics & Neurophysics at the University of Marburg, Germany, where these methods have been used exclusively for 25 years in the laboratories of Professor Reinhard Eckhorn and Professor Reitboeck. Since becoming commercially available, our systems are also being used by an increasing number of leading U.S., Japanese and European neurophysiological research laboratories.
For example, we fitted out the laboratory of the Nobel Prize winner Professor Torsten Wiesel in New York with our Eckhorn multielectrode-system, the new laboratory of Professor Nikos Logothetis at the Max-Planck-Institute for biological Cybernetics in Tübingen, Germany, and the laboratories of Prof. Dr. Vernon B. Mountcastle at the Johns Hopkins University in Baltimore, U.S.A.
The method is probably the most powerful and versatile multi-microelectrode recording technique presently available. The mechanical and electronical equipment, as well as the software, is developed and fabricated on the premises of Thomas RECORDING GmbH in Giessen, Germany.
As a specialist of microelectrodes for physiological and especially neurophysiological research, Thomas RECORDING was the first company in the world to develop 4-cores and 7-cores quartz-platinum-tungsten microelectrodes. These electrodes allow multi-site recordings in an area of about 0.002 mm≤ with 4- or 7-cores independently of each other. The 4-cores and 7-cores microelectrodes are exclusively produced and sold for the world market by Thomas RECORDING.
In 1999 Thomas RECORDING was the winner of an Innovation Prize granted by the German Ministry of Economics. This prize was awarded for the worlds first 64-channel multielectrode manipulator system for brain research, developed by our company.We stress the importance of speed, reliability and of cooperation with our customers, in order to develop and realize new ideas and technical solutions.
Thomas Singlecore Microelectrodes
The Thomas RECORDING quartz glass insulated platinum/tungsten fiber microelectrodes were developed by Prof. Dr. Dr. Heribert Reitboeck and Uwe Thomas at the end of the 1970s in the Reitboeck Lab, Neurophysics Department of University of Marburg, Germany. Since that time metal microelectrodes were widely used in neurophysiology and a large variety of fabrication techniques has been reported.
Reitboeck reported, that in some experimental situations these electrode techniques had drawbacks: exact control not only of the tip size, but of the tip geometry was difficult to achieve with conventional electrode fabrication techniques. Exact control is desirable if many electrodes with identical electrical characteristics are required, or if the tip geometry is to be optimized for a particular recording situation; the diameter of the shank cone of these electrodes increases with penetration depth and it can become large enough to cause serious displacement or rupture of superior tissue if large penetration depths are required; the shaft diameter of conventional microelectrodes, generally was large which makes it impossible to use these electrodes in closely spaced parallel electrode arrays for multi-unit recordings. In order to overcome these drawbacks the Thomas microelectrodes were developed. The results of this development were published by Reitboeck at the beginning of the 1980s.
Thomas Multicore Microelectrodes
The Thomas multicore microelectrodes were designed by Heribert Reitboeck and Uwe Thomas in 1987 in the Reitboeck lab at the University of Marburg, Germany (see Figure 02).
First in vivo recordings with this heptode were made by Matthias Munk. A method for classifying neuronal spikes was proposed and achieved by Kaneko et al. in 1996 by multi-unit recording using the Thomas heptodes. Later Tamura described a method for quantitative analysis of heptode data recorded in the macaque inferior temporal cortex.
The 4-cores-quartz-platinum/tungsten microelectrode (tetrode) was designed and manufactured as a result of the heptode work in summer 1993. The Thomas tetrode and heptode design was published by Schmidt in 1999. This Thomas tetrode consists of 4 metal wires each one insulated from each other by quartz glass. The metal is an alloy of 95% platinum and 5% tungsten. The tetrode fabrication method is based on the same technique as it is used for the fabrication of quartz glass insulated platinum tungsten single microelectrodes first described by Reitboeck in 1983.
The result of the fabrication process is a thin fiber microelectrode with constant spaced metal wires in a concentric arrangement of three wires arranged around one center core like shown in Figure 03.