Boulis N M, Davis M
Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut.
Behav Neurosci. 1989 Jun;103(3):504-8. doi: 10.1037//0735-7044.103.3.504.
The acoustic startle reflex can be facilitated by the presentation of a train of footshocks presented in rapid succession (footshock sensitization). Acoustic startle is a short-latency reflex mediated by a neural circuit consisting of the ventral cochlear nucleus (VCN), ventral nucleus of the lateral lemniscus (VLL), the nucleus reticularis pontis caudalis (RPC), and the spinal cord. The present study sought to determine the point along this pathway where footshocks might ultimately alter neural transmission to affect startle response. Rats were implanted bilaterally with stimulating electrodes in either the VCN, VLL, or RPC. Startle could be elicited acoustically with a noise burst or electrically with a single-pulse stimulus to either the VCN, VLL, or RPC before and after a train of ten 0.6-mA, 500-ms shocks presented at a rate of 1 shocks/s. Startle elicited acoustically or electrically in the VCN or VLL was significantly elevated following shocks. In contrast, startle elicited from the RPC showed no sensitization, even though startle elicited acoustically from the same animals during the same test session was facilitated. These data suggest that footshock sensitization ultimately alters transmission in the startle circuit at the RPC.
一连串快速呈现的足部电击（足部电击敏化）可增强听觉惊吓反射。听觉惊吓是一种短潜伏期反射，由一个神经回路介导，该神经回路包括腹侧耳蜗核（VCN）、外侧丘系腹侧核（VLL）、脑桥尾侧网状核（RPC）和脊髓。本研究旨在确定在这条通路中，足部电击最终可能改变神经传递以影响惊吓反应的位点。给大鼠双侧植入刺激电极，电极分别置于VCN、VLL或RPC中。在以1次/秒的频率施加一系列十次0.6毫安、500毫秒的电击前后，可通过噪声爆发以听觉方式引发惊吓，也可通过对VCN、VLL或RPC施加单脉冲刺激以电方式引发惊吓。在电击后，通过听觉或电方式在VCN或VLL中引发的惊吓显著增强。相比之下，即使在同一测试期间从同一动物以听觉方式引发的惊吓得到了增强，但从RPC引发的惊吓并未表现出敏化现象。这些数据表明，足部电击敏化最终会改变惊吓回路中RPC处的传递。
