Microelectrode array evaluation of gut pacemaker activity in wild-type and W/W(v) mice

Area of Science:

• Gastroenterology
• Neuroscience
• Physiology

Background:

• Interstitial cells of Cajal in the myenteric plexus (ICC-MyP) form networks crucial for gastrointestinal (GI) motility.
• Their role in coordinating electrical activity and potential impairments in motility disorders require functional assessment methods.

Purpose of the Study:

• To propose and validate a novel method for assessing the electrical activity and network function of ICC-MyP.
• To compare ICC-MyP network function in wild-type (WT) and W/W(v) mice using this new method.

Main Methods:

• Simultaneous measurement of field potentials using an 8x8 microelectrode array (MEA) in mouse ileal preparations.
• Pharmacological isolation of ICC-MyP activity by suppressing smooth muscle and neuronal activity with nifedipine and tetrodotoxin (TTX).
• Spatio-temporal and spectral analyses of electrical activity.

Main Results:

• WT mice exhibited synchronized basal electrical activity with a distinct propagation delay, characteristic of a functional ICC-MyP network.
• W/W(v) mice displayed irregular, low-amplitude electrical activity lacking the prominent pacemaker peak seen in WT.
• Spectral analysis revealed significantly lower power in the 9.4-27.0 cycles per minute range for W/W(v) compared to WT mice.

Conclusions:

• Microelectrode array measurements confirm that network-forming ICC-MyP generate and coordinate basal electrical activity.
• The study highlights the utility of MEA for uncovering functional impairments in ICC networks, relevant to GI motility disorders.