Shors T J, Matzel L D
Department of Psychology, Princeton University, NJ 08544, USA.
Behav Brain Sci. 1997 Dec;20(4):597-614; discussion 614-55. doi: 10.1017/s0140525x97001593.
Long-term potentiation (LTP) is operationally defined as a long-lasting increase in synaptic efficacy following high-frequency stimulation of afferent fibers. Since the first full description of the phenomenon in 1973, exploration of the mechanisms underlying LTP induction has been one of the most active areas of research in neuroscience. Of principal interest to those who study LTP, particularly in the mammalian hippocampus, is its presumed role in the establishment of stable memories, a role consistent with "Hebbian" descriptions of memory formation. Other characteristics of LTP, including its rapid induction, persistence, and correlation with natural brain rhythms. provide circumstantial support for this connection to memory storage. Nonetheless, there is little empirical evidence that directly links LTP to the storage of memories. In this target article we review a range of cellular and behavioral characteristics of LTP and evaluate whether they are consistent with the purported role of hippocampal LTP in memory formation. We suggest that much of the present focus on LTP reflects a preconception that LTP is a learning mechanism, although the empirical evidence often suggests that LTP is unsuitable for such a role. As an alternative to serving as a memory storage device, we propose that LTP may serve as a neural equivalent to an arousal or attention device in the brain. Accordingly, LTP may increase in a nonspecific way the effective salience of discrete external stimuli and may thereby facilitate the induction of memories at distant synapses. Other hypotheses regarding the functional utility of this intensely studied mechanism are conceivable; the intent of this target article is not to promote a single hypothesis but rather to stimulate discussion about the neural mechanisms underlying memory storage and to appraise whether LTP can be considered a viable candidate for such a mechanism.
长期增强效应（LTP）在操作上被定义为在传入纤维高频刺激后突触效能的持久增加。自1973年首次对该现象进行完整描述以来，对LTP诱导机制的探索一直是神经科学中最活跃的研究领域之一。研究LTP的人，特别是在哺乳动物海马体中研究LTP的人，最感兴趣的是它在稳定记忆形成中假定的作用，这一作用与记忆形成的“赫布”描述一致。LTP的其他特征，包括其快速诱导、持久性以及与自然脑节律的相关性，为这种与记忆存储的联系提供了间接支持。然而，几乎没有实证证据直接将LTP与记忆存储联系起来。在这篇目标文章中，我们回顾了LTP的一系列细胞和行为特征，并评估它们是否与海马体LTP在记忆形成中所声称的作用一致。我们认为，目前对LTP的许多关注反映了一种先入之见，即LTP是一种学习机制，尽管实证证据往往表明LTP不适合这一角色。作为作为记忆存储设备的替代方案，我们提出LTP可能相当于大脑中的一种唤醒或注意力设备。因此，LTP可能以非特异性方式增加离散外部刺激的有效显著性，从而促进远处突触处记忆的诱导。关于这一深入研究机制的功能效用，还可以设想其他假设；这篇目标文章的目的不是推广单一假设，而是激发关于记忆存储背后神经机制的讨论，并评估LTP是否可被视为这种机制的可行候选者。
