Department of Physiology, University of Alberta, Edmonton, Canada.
Adv Exp Med Biol. 2010;669:91-5. doi: 10.1007/978-1-4419-5692-7_19.
Rhythmogenic pre-Bötzinger complex (preBötC) networks are inspiratory active in brainstem slices that are typically studied in 7-9 mM K(+)instead of physiological extracellular (3 mM) K(+). Also superfusate Ca(2+) is often high (up to 2.4 mM) compared to the most common physiological value (1.2 mM). Because both cations are potent neuromodulators, it is desirable to keep them as close as possible to normal levels for minimizing modulation of the isolated preBötC. We found that modestly raised Ca(2+) depresses preBötC slice rhythm while K(+) elevation counters this inhibition and low Ca(2+) accelerates inspiratory bursting. A Ca(2+) range of 0.75-1 mM and K(+) levels between 4-6 mM may be optimal for long term stable slice rhythm.
节律性前 Bötzinger 复合体 (preBötC) 网络在脑片上表现为吸气活性，而这些脑片通常是在 7-9mM K+而不是生理细胞外 (3mM) K+中进行研究的。此外，与最常见的生理值 (1.2mM) 相比，灌流液中的 Ca2+通常较高 (高达 2.4mM)。由于这两种阳离子都是有效的神经调质，因此最好将它们保持在尽可能接近正常水平，以最小化对分离的 preBötC 的调制。我们发现，适度升高的 Ca2+会抑制 preBötC 切片节律，而升高 K+则会抵消这种抑制作用，而低 Ca2+则会加速吸气爆发。Ca2+范围为 0.75-1mM 和 K+水平在 4-6mM 之间可能是长期稳定切片节律的最佳条件。
