鳌虾口胃神经节三相节律的观察及四乙胺的影响作用

The Observation of Three-phase Rhythm and Influence of Tetraethylammonium in the Stomatogastric Ganglion of Crayfish

龙虾口胃神经节(stomatogastric ganglion,STG)幽门网络中,PD(pyloric dilatorneuron)、LP(lateral pyloric neuron)、PY(pyloric neuron)神经元依次放电产生的三相节律,经常被用于研究中枢模式发生器(central pattern generator,CPG)神经网络的电活动。本实验选用克氏鳌虾,记录其在正常生理状态下和施加钙依赖钾离子通道阻断剂四乙胺(tetraethylammonium,TEA)后,STG的三相节律。TEA加入后,LP和PY神经元的放电节律模式发生了变化,但三相节律中,各神经元的放电顺序仍然保持不变。三相放电节律周期和PY神经元放电持续期的减少具有极显著意义(P<0.01);LP神经元放电持续期的增加有显著意义(P<0.05);LP、PD神经元放电峰峰间期(interspike interval,ISI)的减少有显著性意义(P<0.05)。上述结果表明,克氏鳌虾可以用于STG网络电活动的研究;TEA的加入导致了幽门节律多个指标的变化,如放电节律模式和放电周期等,但是三相节律的顺序关系没有发生改变。

Three-phase rhythm composed of the firings generated by PD,LP and PY pyloric neurons in sequence in the stomatogastric ganglion（STG） of spiny lobster,which is often used to study the electrical activity of central pattern generator（CPG）.Three-phase rhythms were recorded in normal condition and in condition of TEA（mmol/L） being as blocker of the Ca2＋-dependent potassium currents（I K（ca）） in STG of crayfish that was chosen as experimental model in this paper.The firing patterns of LP and PY neurons were changed under the influence of tetraethylammonium（TEA）,while the firing sequence corresponding to each neuron of the three-phase rhythm did not change.The period of three-phase rhythm and the firing duration of PY neuron were decreased significantly（P〈0.01）.The firing duration of LP neuron was increased significantly（P〈0.05）.The interspike intervals of LP and PD neurons were decreased significantly（P〈0.05）.The results showed that some indicators of three-phase rhythm of PD,LP,PY pyloric neurons in crayfish,such as firing pattern and period,were influenced,but the sequence of the three-phase rhythm did not change in condition of TEA.It indicates that the crayfish can be employed to study the electronic activities of STG.