Sasa M, Munekiyo K, Takaori S
Jpn J Pharmacol. 1974 Dec;24(6):863-8. doi: 10.1254/jjp.24.863.
All experiments were performed on cats immobilized with gallamine. In the rostral part of spinal trigeminal nucleus (STN), single fiber action potential with a consistent and short latency was elicited by electrical stimulation of the locus coeruleus (LC). When 2 mg of 6-hydroxydopamine (6-OHDA) dissolved in 5% ascorbic acid solution was applied into the lateral ventricle, the STN field potential produced by LC stimulation was reduced in amplitude within 20 hr. The STN potential elicited by trigeminal nerve stimulation, however, was unaffected until 24 hr after 6-OHDA. The drug also blocked the inhibitory effect of LC conditioning stimulation on the STN potential elicited by trigeminal nerve stimulation, whereas it did not modify the inhibitory effect of conditioning stimulation of the sensory cortex on the STN potential. Ascorbic acid solution, a solvent, affected neither the STN potential by LC stimulation, nor the inhibitory effect of LC neurons on the STN potential elicited by trigeminal nerve stimulation. These results strongly suggest the existence of noradrenergic fiber from the LC to STN, through which inhibition of the STN neurons is produced.
所有实验均在使用三碘季铵酚固定的猫身上进行。在三叉神经脊束核（STN）的吻侧部分，通过电刺激蓝斑（LC）可诱发潜伏期一致且较短的单纤维动作电位。当将溶解于5%抗坏血酸溶液中的2毫克6-羟基多巴胺（6-OHDA）注入侧脑室时，LC刺激所产生的STN场电位在20小时内振幅降低。然而，三叉神经刺激所诱发的STN电位在注射6-OHDA后24小时内未受影响。该药物还阻断了LC条件刺激对三叉神经刺激所诱发的STN电位的抑制作用，而它并未改变感觉皮层条件刺激对STN电位的抑制作用。作为溶剂的抗坏血酸溶液，既不影响LC刺激所产生的STN电位，也不影响LC神经元对三叉神经刺激所诱发的STN电位的抑制作用。这些结果有力地表明，存在从LC到STN的去甲肾上腺素能纤维，通过该纤维可对STN神经元产生抑制作用。
