Laskey W, Schondorf R, Polosa C
J Auton Nerv Syst. 1984 Sep;11(2):201-6. doi: 10.1016/0165-1838(84)90077-8.
Sympathetic preganglionic neuron (SPN) activity (mass or single unit discharge) was recorded extracellularly from axons of the cervical sympathetic trunk (CST) in unanaesthetized, midcollicular decerebrate or C1 spinal anemically decerebrate cats which were paralyzed and artificially ventilated. Phrenic motoneuron activity was also recorded in the midcollicular preparation. The drug 4-aminopyridine (4-AP) was administered intravenously. Doses of 0.5 to 1.0 mg/kg increased the background firing rate of SPNs in a dose-dependent manner. These doses increased the repetition rate of phrenic nerve bursts and, in a parallel fashion, that of the inspiration-synchronous activity of the CST. In contrast, the action of 4-AP on activity evoked by stimulation of high threshold myelinated afferents in the radial, femoral or pelvic nerve, or in the L7 dorsal root, was very variable. The evoked responses could be increased, decreased or not affected by the drug. Thus, treatment with 4-AP produces a graded increase in background firing of SPNs, but the drug is ineffective at reliably enhancing somato- or viscero-sympathetic reflexes.
在未麻醉、中脑水平去大脑或 C1 脊髓贫血去大脑且已麻痹并进行人工通气的猫中，从颈交感干（CST）轴突细胞外记录交感神经节前神经元（SPN）活动（群体或单单位放电）。在中脑水平制备中也记录膈运动神经元活动。静脉注射药物 4-氨基吡啶（4-AP）。剂量为 0.5 至 1.0 mg/kg 时，SPN 的背景放电频率呈剂量依赖性增加。这些剂量增加了膈神经冲动的重复频率，并且以平行方式增加了 CST 的吸气同步活动频率。相反，4-AP 对由刺激桡神经、股神经或盆神经或 L7 背根中的高阈值有髓传入纤维所诱发的活动的作用非常多变。诱发反应可能会增加、减少或不受该药物影响。因此，用 4-AP 治疗会使 SPN 的背景放电呈分级增加，但该药物在可靠增强躯体或内脏交感反射方面无效。
