Hamood Albert W, Haddad Sara A, Otopalik Adriane G, Rosenbaum Philipp, Marder Eve
Volen Center and Biology Department (all authors), M.S. 013, Brandeis University, Waltham, MA 02545 USA.
eNeuro. 2015 Jan;2(1). doi: 10.1523/ENEURO.0058-14.2015.
The crustacean stomatogastric ganglion (STG) receives descending neuromodulatory inputs from three anterior ganglia, the paired commissural ganglia (CoGs) and the single esophageal ganglion (OG). In this paper we provide the first detailed and quantitative analyses of the short- and long-term effects of removal of these descending inputs (decentralization) on the pyloric rhythm of the STG. Thirty minutes after decentralization, the mean frequency of the pyloric rhythm dropped from 1.20 Hz in control to 0.52 Hz. Whereas the relative phase of pyloric neuron activity was approximately constant across frequency in the controls, after decentralization this changed markedly. Nine control preparations kept for 5-6 days maintained pyloric rhythm frequencies close to their control values. Nineteen decentralized preparations kept for 5-6 days dropped slightly in frequency from those seen at 30 minutes after decentralization, but then displayed stable activity over 6 days. Bouts of higher frequency activity were intermittently seen in both control and decentralized preparations, but the bouts began earlier and were more frequent in the decentralized preparations. Although the bouts may indicate that the removal of the modulatory inputs triggered changes in neuronal excitability, these changes did not produce obvious long-lasting changes in the frequency of the decentralized preparations.
甲壳类动物的口胃神经节（STG）接收来自三个前神经节的下行神经调节输入，即成对的连合神经节（CoGs）和单个食管神经节（OG）。在本文中，我们首次对去除这些下行输入（去中枢化）对STG幽门节律的短期和长期影响进行了详细的定量分析。去中枢化30分钟后，幽门节律的平均频率从对照时的1.20赫兹降至0.52赫兹。在对照中，幽门神经元活动的相对相位在不同频率下大致恒定，而去中枢化后则发生了显著变化。9个对照标本保存5 - 6天后，幽门节律频率接近其对照值。19个去中枢化标本保存5 - 6天后，频率较去中枢化30分钟时略有下降，但随后在6天内表现出稳定的活动。在对照和去中枢化标本中均间歇性地出现较高频率活动的发作，但去中枢化标本中的发作开始得更早且更频繁。尽管这些发作可能表明去除调节输入触发了神经元兴奋性的变化，但这些变化并未在去中枢化标本的频率上产生明显的长期变化。
