last updated: 23 April, 2016

This page displays several sets of mapping electrodes that have been constructed and used over the years in the lab.   

Singh brush

Singh BrushThe first assembly built in Al Ain by Mr Sarabjit Singh (1991/2). This 'brush' consists of 240 electrodes, 15 rows and 16 columns with an inter-electrode distance of 1 mm. The tips of the electrodes extend about 3 mm from the dental cement base to allow some fluid to reach the surface of the tissue. Used for the first experiments in slow wave conduction in rabbit duodenum.

Kays brush Built around 1994/5 by Mr Ahmed El-Kays. This assembly consists of 240 electrodes, 10 rows and 24 columns with an inter-electrode distance of 2 mm. The tips of the electrodes also extend about 3 mm from the base. This 'brush' has been used extensively for mapping slow waves and spike patches in feline duodenum.

Betty brush. Built around 1999 by Mrs. B Stephen. This assembly is essentially a copy of the Kays brush except for the fact that the electrodes do not stick out but are cut flush at the base. This brush is used for in vivo mapping studies where the muscle is perfused through its normal circulation. Used at Janssen Research Foundation in Belgium in 2000-2001. Because of a short-circuit in a subset of 16 electrode wires, a new set is currently being built.

sekar2.jpg (143121 bytes) Sekar 32 Row. Built in 2001 by Dhanasekaran. It consists of only one row of 32 electrodes (1 mm inter-electrode distance; free for the last 3-5 mm). Used for electrical/motility studies in isolated intestinal segments.

Sekar 32 Multiple Rows. Built in 2002 by Dhanasekaran. It consists of a single row of 32 electrodes with the electrodes located at a distance of 4 mm. Mr Dhanasekaran is currently building 7 sets of these assemblies (6 x 32 and 1 x 16 = 240) which can be used to map the propagation of slow waves along the whole of the feline small intestine.

Mice Electrode. Built in 2002 by Dhanasekaran. It consists of a single row of 16 electrodes. The electrode wires were glued as close as possible to each other. As the diameter of a Teflon-coated silver wire is about .33 mm, the average inter-electrode distance is approximately 0.35 mm and the total electrode row is 5.5 mm long. We are using this array to record potentials from mice stomach and small intestine.

Bending Electrode Built in 2004 by Atiq. It consists of a single row of 32 electrodes with an inter-electrode distance of 1 mm. The electrodes are embedded in a silicone layer together with 2 perpendicular positioned copper wires. Because the silicone is flexible, the row can be bend manually in either direction (see enlarge picture). The copper wires will hold the row in that position. These electrodes was designed and in use for recording from a loop in small intestine in the open-adomen anesthetized dog.

Technical Notes: The electrodes consists of Teflon-coated silver wires (Cooner Wires, CA) with a diameter of 0.3 mm. The wires are soldered to stainless-steel multi-stranded wires (also Teflon-coated) for connection to the amplifiers with the solder junctions isolated by shrink sleeves.

© W. Lammers 2001-2016