Investigation of emotion and mnemonic functions of the primate limbic system by means of invasive and non-invasive methods

为了阐明septo (SP)-海马（HF）系统的空间和认知功能，我们记录了警觉猴子在执行位置依赖的条件走开任务（PCA）时的神经活动，在PCA任务中，给定物体的反应/强化偶发取决于包含猴子的机动移动装置（cab）的位置，以及在执行不需要条件辨别的位置独立的走开任务时的神经活动。在记录的329个高频神经元中，88个神经元的活动在PCA任务中随着物体的呈现而显著增加或减少。仅在PCA任务中，17个神经元的反应取决于物体、地点和行为的特定组合（特定组合神经元）。只有在PCA任务中，12个神经元对物体的反应是不同的（物体-差异神经元）。这两种神经元类型的特征表明，高频神经元既编码刺激感知，也编码诸如刺激出现的位置、任务中施加的条件关系等属性。这些结果可能是情景记忆的神经生理基础，并提示心衰的空间和非空间功能之间存在联系。在记录的430个SP神经元中，有58个神经元在4个位置的位置期反应存在显著差异。其中8个神经元在客体期和地点期的反应也是位置差异的。91个神经元在客体阶段有差异反应，43个神经元仅在主成分分析任务中有差异反应，19个和2个神经元分别与奖励/非奖励和去/不去相关。结果表明，SP参与了空间信息整合、条件性地点客体关系和奖励/非奖励偶然性。在非侵入性研究中，采用三维重建真实头部模型的偶极追踪（DT）方法研究了猴子体感诱发电位（SEPs）和人类视觉诱发电位（VEPs）的产生机制，该模型可以将表面电位分布等同于相应的等效偶极子。结果表明，偶极子通过SI区从丘脑依次移动到5区，并且偶极子在胼胝体裂隙周围的地形定位与枕叶视网膜切除术非常相似。清醒大鼠全脑短暂性缺血时的脑功能MRI显示，缺血后1小时充血与HF CA1亚区神经元死亡延迟显著相关，大鼠舔食葡萄糖溶液时的脑功能MRI显示下丘脑信号强度增加。少

To elucidate spatial and cognitive function of the septo (SP)-hippocampal (HF) system, neural activity was recorded from alert monkeys during performance of a place-dependent conditional go-nogo task (PCA) task in which response/reinforcement contingencies of given objects were conditional upon the location of a motorized, movable device (cab) containing a monkey, and during the place-independent go-nogo tasks which required no conditional discrimination. Of 329 HF neurons recorded, the activity of 88 increased or decreased significantly in response to the presentation of an object during the PCA task. Responses of 17 neurons depended differentially on specific combinations of object, place and behavior only in the PCA task (specific-combination neurons). Responses of 12 ncurons responded differentially to the objects only in the PCA task (object-differential neurons). Characteristics of the 2 neuron types suggest that HF neurons encode both stimulus percept and attributes such as the … More place where the stimulus is presented, and the conditional relation imposed in the task. These results might be neurophysiological bases of episodic memory, and suggest thet there is linkage between spatial and non-spatial functions in the HF.Of 430 SP neurons recorded, the responses during the place phase in the 4 places were significantly different in 58 neurons. Responses of 8 of these neurons were also place-differential during the object phase as well as the place phase. Of 91 neurons responding differentially during the object phase, 43 responded differentially only in the PCA task, 19 and 2 neurons were related to the reward/nonreward and go/nogo contingencies, respectively. The results suggest that the SP is involved in integrating spatial information, conditional place-object relations, and reward/nonreward contingency.In the non-invasive study, generators of monkey somatosensory evoked potentials (SEPs) in monkeys and visual evoked potentials (VEPs) in humans were investigated by dipole tracing (DT) method with 3-dimensional reconstructed real head model, which can equates surface potential distributions to a corresponding equivalent dipole. The results indicated sequcential movement of dipoles from the thalamus to area 5 via the SI area, and topographic localization of the dipoles around the calcarine fissures which were well comparable to the retinotopy in the occipital lobe. The functional MRI of brains of awake rats during transient whole brain ischemia indicated that the post-ischemic hyperemia which lasts 1 hr was significantly correlated to delayd neuronal death in the CA1 subfield of the HF,and those of a rat brain during licking of glucose solution indicated increase in signal intensity in the hypothalamus. Less