de Oliveira Yasmin Guedes, Poltronieri Bruno Costa, Woodruff Erica, da Costa Brunno Freitas, Panizzutti Rogerio Arena
Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
Instituto de Psiquiatria, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
Front Psychiatry. 2023 Apr 13;14:1145783. doi: 10.3389/fpsyt.2023.1145783. eCollection 2023.
Acoustic prepulse inhibition of the startle response (PPI) is a phenomenon characterized by the reduction in the startle reflex caused by the presence of weak and brief stimulus before an intense and sudden stimulus (pulse). These phenomena can be observed in several species, but in humans it is commonly measured by the eyeblink using electromyography. PPI works as an operational measure of sensorimotor gating, which is the ability to suppress motor responses for sensory stimulus. Healthy aging is marked by several changes in neural processing, like inhibitory functioning decline. In this line, PPI measure can be a potential biomarker for changes related to the aging process.
In this research we aim to investigate if PPI is reduced with aging and if this reduction would be associated with cognitive functioning of older adults. To this aim, we compared PPI levels of older adults (over 60 years old) with PPI levels of young adults (from 18 to 28 years old).
With that, we found, significantly lower PPI level ([1,25] = 7.44 = 0.01) and lower startle amplitude startle amplitude: (U = 26.000 = 0.001) in older adults than in young adults. However, we did not find differences in levels of habituation (T = -1.1 = 0.28) and correlation between PPI and cognition within the sample of healthy older adults.
Our results demonstrate that aging is a factor that affects PPI and that it does not seem to predict cognition, however, future studies should explore the potential of using PPI for monitoring cognitive changes associated with techniques such as cognitive training.
惊吓反应的听觉前脉冲抑制（PPI）是一种现象，其特征在于在强烈且突然的刺激（脉冲）之前存在微弱且短暂的刺激会导致惊吓反射减弱。这些现象在多个物种中都能观察到，但在人类中通常通过使用肌电图的眨眼来测量。PPI作为感觉运动门控的一种操作指标，感觉运动门控是抑制对感觉刺激的运动反应的能力。健康衰老的特征是神经加工出现一些变化，如抑制功能下降。就此而言，PPI测量可能是与衰老过程相关变化的潜在生物标志物。
在本研究中，我们旨在调查PPI是否会随着衰老而降低，以及这种降低是否与老年人的认知功能相关。为此，我们将老年人（60岁以上）的PPI水平与年轻人（18至28岁）的PPI水平进行了比较。
由此，我们发现老年人的PPI水平显著低于年轻人（[1,25] = 7.44，P = 0.01），惊吓幅度也较低（U = 26.000，P = 0.001）。然而，我们未发现习惯化水平存在差异（T = -1.1，P = 0.28），且在健康老年人样本中，PPI与认知之间也不存在相关性。
我们的结果表明，衰老会影响PPI，但它似乎无法预测认知。然而，未来的研究应探索使用PPI监测与认知训练等技术相关的认知变化的潜力。
