Dipl. Ing. univ. (Ms.Sc.EE) Hans Reiner Polder

(1957-2019)

Principal Investigator

Address

NPI - npi electronic GmbH; Instruments for the Life Sciences
Hauptstrasse 96
71732 Tamm

Homepage

Research topics

Modern electronic instrumentation for neuroscience: npi electronic is a leading expert for instruments based on microelectrode approaches with very high temporal and spatial resolution. Our instruments cover a broad range of applications from intra- and extracellular recording to patch- and voltage-clamp techniques, stimulation, high- resolution drug application and electrochemical detection of transmitter release.

Scientific Approach

We combine methods from control theory and system theory to analyze microelectrode electrophysiological techniques. Based on this analysis we design electronic instruments that overcome the limitations imposed by microelectrodes and patch electrodes. This approach has led to a special compensation circuit for microelectrodes that makes it possible to record without series resistance artifacts from a single electrode (in voltage- and current- clamp mode). The combination of two amplifiers systems yields artifact-free recordings from cell pairs such as gap-junction coupled or synaptically coupled neurons. The high-speed current injection circuit can be used for fast iontophoretic drug application on single synapses (time resolution <1 msec, spatial resolution < 1µm) or juxtacellular filling, single cell transfection and stimulation.

Related Publications

Daniel J., HR. Polder, V. Lessmann & T. Brigadski (2013) Single-cell juxtacellular transfection and recording technique Pflugers Arch Eur J Physiol, http://dx.doi.org/10.1007/s00424-013-1304-2
Polder, H.R., Weskamp M., Linz K. and Meyer R. (2005): Voltage-Clamp and Patch-Clamp Techniques, Chapter 3.4, in: Dhein, St.; Mohr, FW; Delmar, M. (Eds.) Practical Methods in Cardiovascular Research, Springer, Berlin Heidelberg New York 2005
Sutor, B., Grimm Ch.and Polder H.R. (2003): Voltage-Clamp controlled Current-Clamp Recordings from Neurons: An Electrophysiological Technique Enabling the Detection of Fast Potentials Changes at Preset Holding Potentials, Pflugers Arch.446, 133-141.
Polder, H.R. and Swandulla D. (2001);The use of control theory for the design of voltage clamp systems: A Simple and standardized procedure for evaluating system parameters, J. Neurosci. Meth., 109: 97-109
Müller, A., Lauven M., Berkels R., Dhein S., Polder H.R. and Klaus W. (1999): Switched single electrode amplifiers allow precise measurement of gap junction conductance, Am. J. Physiol. 276: C980-88
Draguhn, A., Pfeiffer M., Heinemann U. and Polder H.R. (1997): A simple hardware model for the direct observation of voltage-clamp performance under realistic conditions, J. Neurosci. Meth. 78:105-113