BEHAVIOR AND BRAIN IMAGING IN BABOONS

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。关于调节灵长类动物摄食行为的神经体液因子，人们知之甚少。在早期的工作中，我们证明了由盐耗竭导致的狒狒盐摄取行为的增加需要起作用的脑血管紧张素机制。然而，下丘脑-垂体-肾上腺轴的成分对小鼠、大鼠、兔子和有蹄类动物的盐分和水摄入量具有强烈的刺激作用，对狒狒的摄食行为没有任何影响。这项研究的目的是开发一种将神经体液因子应用于脑结构的狒狒制剂，以便我们可以使用功能磁共振技术观察大脑中心的激活。最初的步骤需要开发一种有色金属套管，即向脑脊液中注入激素和神经递质激动剂和拮抗剂的系统，同时收集fMRI图像用于脑激活观察。一种静脉麻醉方案已经开发出来，可以在采集脑部图像的同时，让狒狒镇静长达3小时。使用这一程序，我们在狒狒身上复制了我们最近在人类身上进行的一项研究，在该研究中，在收集大脑激活的PET图像的同时，使用静脉生理盐水输注来刺激口渴。被高渗盐水激活的狒狒大脑区域与人类研究中激活的大脑中心是相同的。我们将探索非金属插管系统的几种方法，将其植入恒河猴的侧脑室。该系统将能够收集大脑对直接施加到大脑的刺激的激活反应的PET图像。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Very little is known in regard to the neurohumoral factors that regulative ingestive behaviors in primate species. In earlier work, we showed that increased salt intake behavior produced by salt depletion in the baboon requires functional brain angiotensin mechanism. However, components of the hypothalamic-pituitary-adrenal axis that are potent stimuli for salt and water intake in mice, rats, rabbits and ungulates do not have any effect on ingestive behaviors in baboons. The objective of this study is to develop a baboon preparation that will permit administration of neurohumoral factors to brain structures so we can observe activation of brain centers using fMRI technology. The initial steps require development of a non-ferrous metal cannula, system for administration of hormonal and neurotransmitter agonists and antagonists into brain CSF while collecting fMRI images for brain activation observations. An intravenous anesthetic protocol ahs been developed that permits sedation of baboons for periods of up to 3 hours wile collecting brain images. Using this procedure we have replicated in baboons a recent study we conducted in humans in which intravenous saline infusion was used to stimulate thirst while collecting PET images of brain activation. The areas of the baboon brain activated by hypertonic saline were identical to the brain centers activated in the human studies. We will explore several approaches for a non-metallic cannula system for implanting in the baboon lateral brain ventricle. The system will enable the collection of PET images of brain activation responses to stimuli applied directly to the brain.