The acoustic startle response and prepulse inhibition (PPI) of startle are measures related to information processing, which is impaired in schizophrenia. Some studies have provided inconclusive patterns of association between both measures in rodents. We assessed the influence of baseline startle response on PPI in large samples of Roman high-(RHA) and low-avoidance (RLA) rat strains and in genetically heterogeneous stock (HS) rats. Results show that RHAs exhibit a PPI deficit compared to RLA rats, which is present regardless of the startle response levels. HS rats were stratified in two sub-samples according to their high or low PPI (HS-highPPI or HS-lowPPI, respectively) scores, and then they were grouped by their differential baseline startle amplitude (high reactivity –HR- or low reactivity –LR-) within each sub-sample. Differences between high- and low-PPI-stratified HS rats remained regardless of their high or low startle amplitude scores. Thus, the impairments in %PPI found in both RHA and HS-LowPPI rats are present irrespective of the relatively high or low levels of startle amplitude in pulse-alone trials. Another objective of the present study was to evaluate whether habituation to the startling stimulus (i.e., pulse) depends on the initial baseline startle response. RLA rats habituated to the startling stimulus more effectively than RHAs regardless of their baseline startle responses. Conversely, there were no differences in startle habituation in the HS rats grouped by their extreme scores of baseline startle. Altogether, these findings suggest a deficit in information processing in RHA rats, which along with evidence indicating that this strain displays other attentional/cognitive impairments, strengthens the validity of the RHA strain as a putative model of schizophrenia-relevant features.

惊吓的听觉惊吓反应和前脉冲抑制（PPI）是与信息处理相关的措施，在精神分裂症中受到损害。一些研究提供了啮齿动物两种测量之间关联的不确定模式。我们评估了罗马高 (RHA) 和低回避 (RLA) 大鼠品系和遗传异质性股票 (HS) 大鼠的大样本中基线惊吓反应对 PPI 的影响。结果表明，与 RLA 大鼠相比，RHA 表现出 PPI 缺陷，无论惊跳反应水平如何，这种缺陷都存在。HS 大鼠根据其高或低 PPI（分别为 HS-highPPI 或 HS-lowPPI）评分在两个子样本中分层，然后根据它们的差异基线惊吓幅度（高反应性 -HR- 或低反应性 - LR-) 在每个子样本中。高和低 PPI 分层的 HS 大鼠之间的差异仍然存在，无论它们的惊吓幅度得分是高还是低。因此，在 RHA 和 HS-LowPPI 大鼠中发现的 %PPI 损伤都存在，而与单独脉冲试验中惊吓幅度的相对高或低水平无关。本研究的另一个目的是评估对惊吓刺激（即脉搏）的习惯是否取决于初始基线惊吓反应。RLA 大鼠比 RHA 更有效地习惯于令人吃惊的刺激，无论它们的基线惊吓反应如何。相反，根据基线惊吓的极端分数分组的 HS 大鼠的惊吓习惯没有差异。总之，这些发现表明 RHA 大鼠的信息处理存在缺陷，