Davis M, Commissaris R L, Cassella J V, Yang S, Dember L, Harty T P
Brain Res. 1986 Apr 16;371(1):58-69. doi: 10.1016/0006-8993(86)90810-3.
This study sought to determine where drugs that are known to alter sensorimotor reactivity measured with the acoustic startle reflex ultimately act within the acoustic startle pathway. To do this, startle was elicited either acoustically or electrically within various nuclei believed to comprise the acoustic startle pathway. Direct infusion of serotonin into the subarachnoid space of the lumbar spinal cord increased acoustic startle and startle elicited electrically through the ventral cochlear nucleus (VCN) to a comparable degree. Subconvulsant doses of strychnine increased startle elicited acoustically or electrically through either the VCN or the nucleus reticularis pontis caudalis (RPC), pointing to a spinal locus of action of strychnine after systemic administration. In marked contrast, the dopamine agonists d-amphetamine and apomorphine consistently increased acoustic startle but actually depressed startle elicited electrically through the VCN or the RPC. These later results suggest that dopamine agonists increase sensorimotor reactivity measured with acoustic startle by acting on sensory rather than motor parts of the reflex arc.
本研究旨在确定已知可改变通过听觉惊吓反射测量的感觉运动反应性的药物最终在听觉惊吓通路中的作用部位。为此，在被认为构成听觉惊吓通路的各个核团内，通过听觉或电刺激引发惊吓反应。将血清素直接注入腰段脊髓的蛛网膜下腔，可使听觉惊吓以及通过腹侧耳蜗核（VCN）电刺激引发的惊吓反应增加到相当程度。亚惊厥剂量的士的宁可增加通过VCN或尾侧脑桥网状核（RPC）听觉或电刺激引发的惊吓反应，表明全身给药后士的宁的作用部位在脊髓。与之形成显著对比的是，多巴胺激动剂d-苯丙胺和阿扑吗啡持续增加听觉惊吓，但实际上却抑制了通过VCN或RPC电刺激引发的惊吓反应。这些结果表明，多巴胺激动剂通过作用于反射弧的感觉而非运动部分来增加通过听觉惊吓测量的感觉运动反应性。
