BEHAVIOR AND BRAIN IMAGING IN BABOONS

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。关于调节灵长类动物摄食行为的神经体液因素，我们知之甚少。在早期的研究中，我们发现狒狒盐分消耗导致的盐摄入量增加需要功能性脑血管紧张素机制。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和水摄入有强烈的刺激作用，但对狒狒的摄入行为没有任何影响。本研究的目的是开发一种狒狒制剂，允许将神经体液因子施用于大脑结构，这样我们就可以使用功能磁共振成像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，一种将激素和神经递质激动剂和拮抗剂注入脑脊液的系统，同时收集功能磁共振成像图像进行脑激活观察。已经开发出一种静脉麻醉方案，可以在收集大脑图像的同时对狒狒进行长达3小时的镇静。我们用这个方法在狒狒身上复制了我们最近在人类身上进行的一项研究，该研究使用静脉输注生理盐水来刺激口渴，同时收集大脑活动的PET图像。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相同。我们将探讨几种方法的非金属套管系统植入狒狒侧脑室。该系统将能够收集直接应用于大脑的刺激的大脑激活反应的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.