Vertes R P, Albo Z, Viana Di Prisco G
Center for Complex Systems and Brain Sciences, Florida Atlantic University, Boca Raton, FL 33431, USA.
Neuroscience. 2001;104(3):619-25. doi: 10.1016/s0306-4522(01)00131-2.
In 1937 Papez described an anatomical circuit (or loop) beginning and ending in the hippocampal formation that he proposed subserved emotional experience (Papez, 1937). Specifically, the projections of the circuit were as follows: hippocampal formation--> mammillary bodies--> anterior thalamus--> cingulate cortex--> parahippocampal gyrus--> hippocampal formation. Although the circuit has been refined based on subsequent anatomical findings (Amaral and Witter, 1995; Shibata, 1992; Van Groen and Wyss, 1995), the major links of the circuit unquestionably represent a prominent system of connections in the mammalian brain. Hence, the enduring nature of 'Papez's circuit'. Unlike, however, its persistence as anatomical entity, the proposed functional role for the circuit has been less resilient. The early notion that Papez's circuit subserves emotional experience/expression has been abandoned (LeDoux, 1993) and replaced by the proposal that it is primarily involved in mnemonic functions (Aggleton and Brown, 1999). Lesions of each of the major components of the circuit have been shown to disrupt memory (Aggleton and Brown, 1999; Sutherland et al., 1988; Sziklas and Petrides, 1993). The mammillary bodies represent a major output from the hippocampus in Papez's circuit (Amaral and Witter, 1995). It has recently been shown that cells of mammillary body fire rhythmically in bursts synchronous with the theta rhythm of the hippocampus (Bland et al., 1995; Kirk et al., 1996; Kocsis and Vertes, 1994, 1997) and that this rhythmical activity is dependent upon the action of the hippocampus on the mammillary bodies (Bland et al., 1995; Kirk et al., 1996). It is well established that the mammillary bodies project massively to the anterior thalamus (Shibata, 1992), which taken together with the demonstration that mammillary body cells fire synchronously with theta, suggests that the mammillary bodies may act on the anterior thalamus, possibly in the manner that the hippocampus acts on the mammillary bodies, to rhythmically activate cells of the anterior thalamus at theta frequency. We demonstrated that approximately 75% of cells of the anterior ventral nucleus of the thalamus fire rhythmically synchronous with the hippocampal theta rhythm and the activity of 46% of these anterior ventral neurons was highly correlated with theta. These findings, together with demonstration of theta-rhythmically firing cells in other structures of Papez's circuit, indicate that a theta-rhythmic signal may resonate throughout Papez's circuit, possibly involved in the control of mnemonic functions of the circuit.
1937年，帕佩兹描述了一个始于并终于海马结构的解剖学环路，他认为该环路与情绪体验有关（帕佩兹，1937）。具体而言，该环路的投射如下：海马结构→乳头体→前丘脑→扣带回皮质→海马旁回→海马结构。尽管基于后续的解剖学发现，该环路已得到完善（阿马拉尔和维特，1995；柴田，1992；范·格罗恩和怀斯，1995），但其主要连接无疑代表了哺乳动物大脑中一个重要的连接系统。因此，“帕佩兹环路”具有持久的特性。然而，与它作为解剖学实体的持久性不同，该环路所提出的功能作用却不那么具有韧性。早期认为帕佩兹环路与情绪体验/表达有关的观点已被摒弃（勒杜，1993），取而代之的是它主要参与记忆功能的观点（阿格leton和布朗，1999）。该环路各主要组成部分的损伤已被证明会破坏记忆（阿格leton和布朗，1999；萨瑟兰等人，1988；齐克拉什和彼得里德斯，1993）。在帕佩兹环路中，乳头体是海马的主要输出部位（阿马拉尔和维特，1995）。最近的研究表明，乳头体中的细胞以与海马θ节律同步的爆发形式有节奏地放电（布兰德等人，1995；柯克等人，1996；科西斯和韦尔特斯，1994，1997），并且这种节律性活动依赖于海马对乳头体的作用（布兰德等人，1995；柯克等人，1996）。众所周知，乳头体大量投射到前丘脑（柴田，1992），这与乳头体细胞与θ同步放电的证明相结合，表明乳头体可能以前丘脑作用于乳头体的方式作用于前丘脑，以θ频率有节奏地激活前丘脑的细胞。我们证明，丘脑前腹核中约75%的细胞与海马θ节律同步有节奏地放电，其中46%的前腹侧神经元的活动与θ高度相关。这些发现，连同在帕佩兹环路其他结构中θ节律性放电细胞的证明，表明θ节律信号可能在整个帕佩兹环路中产生共鸣，可能参与该环路记忆功能的控制。
