Movement based artifacts may contaminate extracellular electrical recordings from GI muscles

Area of Science:

• Gastroenterology
• Neurogastroenterology
• Physiology

Background:

• Electrical slow waves regulate stomach contractions and gastric emptying.
• Gastroparesis and other motility disorders are linked to abnormal slow wave activity.
• Current methods for measuring slow waves often use extracellular recordings.

Purpose of the Study:

• To investigate the impact of muscle contractions and movement on biopotential recordings in murine gastric muscles.
• To differentiate between true electrical slow waves and movement-induced artifacts in extracellular recordings.

Main Methods:

• Utilized array and silver electrodes for extracellular biopotential recordings from murine gastric muscles.
• Administered nifedipine and wortmannin to block contractile movements and assess their effect on biopotentials.
• Performed intracellular microelectrode recordings for comparison with extracellular measurements.

Main Results:

• Extracellular recordings captured propagating biopotentials that were blocked by contractile inhibitors (nifedipine, wortmannin).
• Intracellular recordings revealed authentic slow waves at a higher frequency, unaffected by movement suppression.
• Movement alone, even minor stretches of paralyzed gastric tissue, induced electrical transients mimicking extracellular signals.

Conclusions:

• Significant movement artifacts contaminate extracellular recordings of murine gastric biopotentials.
• Movement suppression is essential for accurate extracellular monitoring of gastric electrical activity.
• This highlights the need for rigorous controls in studies of gastric electrical propagation and coordination.