Dialysis membrane-enforced microelectrode array measurement of diverse gut electrical activity.
A variety of electrical activities occur depending on the functional state in each section of the gut, but the application of microelectrode array (MEA) is rather limited. We thus developed a dialysis membranes-enforced technique to investigate diverse and complex spatio-temporal electrical activity in the gut. Muscle sheets isolated from the gastrointestinal (GI) tract of mice along with a piece of dialysis membrane were woven over and under the strings to fix them to the anchor rig, and mounted on an 8×8 MEA (inter-electrode distance=150µm). Small molecules (molecular weight <12,000) were exchanged through the membrane, maintaining a physiological environment. Low impedance MEA was used to measure electrical signals in a wide frequency range. We demonstrated the following examples: 1) pacemaker activity-like potentials accompanied by bursting spike-like potentials in the ileum; 2) electrotonic potentials reflecting local neurotransmission in the ileum; 3) myoelectric complex-like potentials consisting of slow and rapid oscillations accompanied by spike potentials in the colon. Despite their limited spatial resolution, these recordings detected transient electric activities that optical probes followed with difficulty. In Addition, propagation of pacemaker-like potential was visualized in the stomach and ileum. These results indicate that the dialysis membrane-enforced technique largely extends the application of MEA, probably due to stabilisation of the access resistance between each sensing electrode and a reference electrode and improvement of electric separation between sensing electrodes. We anticipate that this technique will be utilized to characterise spatio-temporal electrical activities in the gut in health and disease.
Department of Cell Physiology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan.
Naoko
N
Iwata
Department of Pediatric Surgery, Keio University School of Medicine, Tokyo 160-8582, Japan.
Takumi
T
Fujimura
Department of Cell Physiology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan.
Chiho
C
Takai
Department of Cell Physiology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan.
Kei
K
Odani
Department of Cell Physiology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan.
Shin
S
Kawano
Department of Cell Physiology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan. Electronic address: h44673a@nucc.cc.nagoya-u.ac.jp.
Shinsuke
S
Nakayama
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation*; D003106:Colon / Q000502:physiology; D003956:Dialysis / Q000295:instrumentation; D004594:Electrophysiology / Q000295:instrumentation*; D007082:Ileum / Q000502:physiology; D008567:Membranes, Artificial; D051379:Mice; D008839:Microelectrodes
D008567:Membranes, Artificial
Access resistance; Dialysis membrane; Electric complex; Electric separation; Pacemaker; Tonic potential