ИСТИНА

Central pattern generators (CPGs) are cellular networks or single cells that produce rhythmic patterned outputs in isolation from sensory feedback. Cellular and molecular mechanisms of circadian (about 24 hours) and fast (with period of seconds) rhythms are well studied, while less attention has been paid to ultradian rhythms with shorter periods (minutes to hours). Calcium wave CPG in the nematode gut is a successful biological model for ultradian rhythms studies. Here we show that intestine CPG cycling could be perturbed by shifting gut cells membrane potential, suggesting participation of plasma membrane voltage gated channels. At the same time we demonstrate, that CPG cycling persist in experiments were membrane potential was continuously clamped at steady voltage levels, that excludes the involvement of plasma membrane voltage gated mechanisms by definition. We suggest that two distinct pacemakers, one based on plasma membrane channels and another based on intrinsic calcium release mechanisms coordinate intestinal CPG cycling.