Conduction in the cephalopod cardio-circulatory system and its neural control

本实验分离了章鱼成对的耳廓和系统脑室，并分离了成对的内脏神经。从后面切到第一心脏神经节。用填充3M KCi的玻璃微电极记录细胞内心肌电位。在ACh或5-HT（5-羟色胺）溶液中沐浴引起的反应。或者通过电刺激内脏神经。乙酰胆碱诱导心室肌细胞的超极化和心脏跳动时的心动过缓或心脏骤停。在超极化过程中，动作电位的幅度和持续时间均有所下降。另一方面。5-HT心室肌细胞去极化与心脏跳动诱发的心动过速。在部分心动过速期间。动作电位幅度明显增加。神经刺激的强度决定了兴奋性还是抑制性作用占主导地位。在神经性心动过速期间。在心室尖峰电位出现之前，舒张期缓慢去极化的上升速率有所增加。在神经性心动过缓期间。或者心脏骤停。心室肌细胞的膜电位超极化超过了正常心动周期的最大值。耳廓和心室心肌细胞均记录了兴奋性连接电位（EJPs）和抑制性连接电位（ijp）。施加于内脏神经的电刺激脉冲能以一比一的刺激电位诱发EJPs或ijp。发现心肌膜电位存在超极化或去极化现象。是对内脏神经刺激的反应。是由个体IJPs的总和得出的。5-羟色胺和肽的存在。鲤鱼。免疫细胞学证实在两栖动物的心血管系统中。Liolophura;腹足动物、腹足动物、胸膜鳃动物和头足动物。章鱼5- ht对系统产生兴奋作用。鲤鱼对系统的影响仍有待研究。少

The paired auricles and systemic ventricle of the heart of octopus hummelincki were isolated together with the paired visceral nerves. Cut posteriorly to the first cardiac ganglion. Glass microelectrodes filled with 3M KCi were used to record intracellular myocardial potentials. Evoked in response to bathing in ACh or 5-HT (serotonin) solution. or by electrical stimulation of the visceral nerve.ACh induced hyperpolarization of ventricular muscle cells and bradycardia or cardiac arrest in beating hearts. Action potentials decreased in amplitude and duration during the AChhyperpolarization.On the other hand. 5-HT depolarized ventricular muscle cells and induced tachycardia in beating hearts. During a portion of the tachycardia. the action potentials increased in amplitude significantly.The intensity of nerve stimulation determined whether excitatory or inhibitory effects predominated. During nerve-induced tachycardia. There was an increase in rate of rise of the slow diastolic depolariza … More tion which preceded ventricular spike potentials. During nerve-induced bradycardia. or cardiac arrest. the membrane potential of ventricular muscle cells was hyperpolarzied beyond the maximum attained in a normal cardiac cycle.Both excitatory junctional plotentials (EJPs) and inhibitory junctional potentials (IJPs) were recordedfrom both auricular and ventricular myocardial cells. Pulses of electrical stimulation applied to the visceral nerve elicited EJPs or IJPs in a one-to-one ratio of stimulus to postjunctional potentials. It was discovered that the hyperpolarization or depolarization of myocardial membrane potential. in response to visceral nerve stimulation. resulted from summation of individual IJPs of EJPs.The presence of 5-HT and a peptide. CARP. was immunocytologically proved in the cardiovascular systems of a amphineuran. Liolophura; gastropods, Aplysia and Pleurobranchaea and a cephalopod. Octopus.5-HT produced excitatory effects on the systems. Effects of CARP on the systems remain to be examined. Less