Memory/Executive Systems in Prefrontal & Temporal Cortex

描述（由申请人提供）：本提案旨在评估灵长类动物前额叶皮层和两个内侧颞叶区域（海马区和鼻皮质）在辅助记忆和执行功能中的存在和本质之间的关系。在恒河猴中，我们将使用交叉损伤/分裂脑技术分离并断开内侧颞叶和前额叶皮层的这两个区域，以评估这两个大脑区域在记忆和执行功能的表现中是否存在功能相互作用。为了评估功能相互作用的存在和性质，有必要首先评估双侧病变对这三个区域的具体影响。因此，在研究的第一阶段，将对双侧前额叶背皮质（BFF）、海马体形成（BHH）或鼻皮质（BRR）损伤的猴子进行认知测试，“其中执行功能”和“记忆”需求将在任务内部和任务之间系统地变化。在第二阶段（“断开”），使用与第一阶段相同的测试电池，一个实验组（CFHS组）将接受单侧前额皮质背侧损伤和对侧海马形成损伤，同时横断前脑连接。这种损伤会使完整的海马体和相对半球的前额皮质分离。第二个实验组（CFRS）将采用相同的单侧前额皮质背侧病变，但对侧鼻皮质病变并横断前脑相交。这种病变将使完整的前额皮质与完整的对侧半球海马旁皮质分离。为了评估这两种“断开”的影响，我们将把他们的表现与三个对照组进行比较。第一个将是手术对照组（OC），也将作为第一阶段双侧病变的对照组。第二组（IFHS）将有单侧海马形成病变，同侧背外侧前额叶病变和前脑相交横断。这将产生与CFHS组相同的脑损伤，在控制脑损伤总量的情况下，但会使同一侧的海马体形成和前额皮质保持完整和“连接”。第三组（IFRS）将有单侧鼻皮质病变，同时有单侧背外侧前额皮质病变和前脑相交横断。这将产生与CFRS组相同程度的脑损伤，但使一侧的鼻腔和前额皮质保持完整和“连接”。

DESCRIPTION (provided by applicant): This proposal is designed to assess the presence and nature of the relationship between the prefrontal cortex and two medial temporal lobe areas (hippocampal formation and rhinal cortices) in subserving memory and executive function in the primate. In the rhesus monkey, we will use a crossed lesion / split brain technique to isolate and disconnect these two regions of the medial temporal lobe from the prefrontal cortex in order to assess whether there exists a functional interaction between these two brain regions in the performance of memory and executive functions. In order to assess the presence and nature of a functional interaction, it will be necessary to first assess the specific effect of bilateral lesions on each of these three regions. Hence, in the first phase of the study, a cognitive test battery," in which executive function" and "mnemonic" demands within and across tasks will be systematically varied, will be administered to monkeys with bilateral lesions of either the dorsal prefrontal cortex (BFF), the hippocampal formation (BHH), or the rhinal cortices (BRR). In the second phase ("disconnections"), using the same test battery as in the first phase, one experimental group (Group CFHS) will receive a unilateral lesion of the dorsal prefrontal cortex and a contralateral lesion of the hippocampal formation together with a transection of the forebrain commissures. This lesion will disconnect the intact hippocampal formation and prefrontal cortex of the opposite hemispheres. The second experimental group (CFRS) will be prepared with the same unilateral lesion of the dorsal prefrontal cortex but a contralateral lesion of the rhinal cortices with transection of the forebrain commissures. This lesion will disconnect the intact prefrontal cortex from the intact parahippocampal cortices of the opposite hemispheres. In order to assess the effect of these two "disconnections", we will compare their performance to three control groups. The first will be an operated control group (OC) that will also serve as controls for the bilateral lesions in the first phase. The second group (IFHS) will have a unilateral hippocampal formation lesion, an ipsilateral dorsolateral prefrontal lesion, and a transection of the forebrain commissures. This will produce brain damage identical to that in group CFHS, controlling for the total brain damage, but will leave the hippocampal formation and prefrontal cortex on the same side intact and "connected". The third group (IFRS) will have a unilateral lesion of the rhinal cortices along with a unilateral lesion of the dorsolateral prefrontal cortex and transection of the forebrain commissures. This will produce the same degree of brain damage to that in group CFRS, but leave the rhinal and prefrontal cortices on one side intact and "connected".