Mapping slow waves and spikes in chronically instr

Authors: L Ver Donck W J E P Lammers B Moreaux D Smets J Voeten J Vekemans J A J Schuurkes B Coulie

Publish Date: 2006/02/11

Volume: 44, Issue: 3, Pages: 170-178

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Abstract

Myoelectric recordings from the intestines in conscious animals have been limited to a few electrode sites with relatively large interelectrode distances The aim of this project was to increase the number of recording sites to allow highresolution reconstruction of the propagation of myoelectrical signals Sets of six unipolar electrodes positioned in a 3×2 array were constructed A silver ring close to each set served as the reference electrodes Interelectrode distances varied from 4 to 8 mm Electrode sets to a maximum of 4 were implanted in various configurations allowing recording from 24 sites simultaneously Four sets of 6 electrodes each were implanted successfully in 11 female Beagles Implantation sites evaluated were the upper small intestine n=10 the lower small intestine n=4 and the stomach n=3 The implants remained functional for 72 months median range 14–273 months Recorded signals showed slow waves at regular intervals and spike potentials In addition when the sets were positioned close together it was possible to reconstruct the propagation of individual slow waves to determine their direction of propagation and to calculate their propagation velocity No signs or symptoms of interference with normal GIfunction were observed in the tested animals With this approach it is possible to implant 24 extracellular electrodes on the serosal surface of the intestines without interfering with its normal physiology This approach makes it possible to study the electrical activities of the GI system at high resolution in vivo in the conscious animalThe authors wish to acknowledge the expert animal care provided by the staff of the Department of Laboratory Animal Science in particular Mr Jef Ceulemans for training the dogs and Mr Piet Dierckx DVM and Mrs Leen Roefs for daily animal care Dr Luc Andries Histogenex NV Edegem Belgium provided the histology images

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