Spontaneous Electrical Activity of Cultured Interstitial Cells of Cajal from Mouse Urinary Bladder

Interstitial cells of Cajal (ICCs) from the urinary bladder regulate detrusor smooth muscle activities. We cultured ICCs from the urinary bladder of mice and performed patch clamp and intracellular Ca2+ ([Ca2+]i) imaging to investigate whether cultured ICCs can be a valuable tool for cellular functional studies. The cultured ICCs displayed two types of spontaneous electrical activities which are similar to those recorded in intact bladder tissues. Spontaneous electrical activities of cultured ICCs were nifedipine-sensitive. Carbachol and ATP, both excitatory neurotransmitters in the urinary bladder, depolarized the membrane and increased the frequency of spike potentials. Carbachol increased [Ca2+]i oscillations and basal Ca2+ levels, which were blocked by atropine. These results suggest that cultured ICCs from the urinary bladder retain rhythmic phenotypes similar to the spontaneous electrical activities recorded from the intact urinary bladder. Therefore, we suggest that cultured ICCs from the urinary bladder may be useful for cellular and molecular studies of ICCs.

Characteristics of Spontaneous Electrical Activities at the Trigger Point in a Chronic Shoulder Pain Patient-A Case of Trigger Point on Trapezuis Muscle- / 全日本鍼灸学会雑誌

[Purpose] The characteristic of electrical activities recorded at the clinical trigger point was examined.<BR>[Materials] A 26-year-old woman complained of chronic shoulder pain. She had a trigger point near GB 21 (Jianjing, Kensei). The electrical activities were recorded at the trigger point and a non- tender point.<BR>[Results] Electrical activities were detected only when the electrode was located on the trigger point andthere was a subjective dull pain sensation. The amplitudes of electrical activities did not change during psychological stress. [ Conclusion ] These results suggest that the electrical activities were the result of nociceptive reflex.