Development of quantitative autoradiographic method for assessing fuctional imaging in living brain slices.

带成像板的生物成像分析系统是近年来发展起来的一种新的生物成像分析系统，与X光片相比，它具有超高灵敏度、高分辨率和宽动态范围等优点。利用生物成像分析系统的优势，我们研究了应用该系统在活体脑切片中进行功能成像的可能性。将300 μ m厚的全脑切片与放射性标记的化合物一起孵育。然后冲洗切片，并将其置于充满Krebs.Ringer溶液的树脂玻璃室的底部。腔室的底部由薄聚丙烯膜组成，以允许来自脑切片的辐射良好地穿透。将腔室置于成像板上。曝光后，用生物成像分析系统扫描成像板，获得脑切片的放射性图像。利用该系统，我们研究了低氧条件下大鼠海马葡萄糖代谢的变化以及[3-H]Ro 1的超高亲和力结合位点 ...更多信息 5-4513，中枢苯二氮卓受体的部分反向激动剂。在缺氧条件下，[14-C]葡萄糖的放射性在所有脑区均观察到增加与对照组相比。不同脑区放射性摄取增加率也有差异。这些结果表明，葡萄糖的利用率增加，由于无氧代谢的加速和能量需求的变化取决于大脑区域在缺氧条件下与对照组相比。另一方面，在[3-H] Ro 15 -4513的体外结合中，当[3-H] Ro 15 -4513浓度低于0.5 nM时，观察到海马中的超高亲和力结合位点。只有当Ro 15 -4513的注射剂量低于3.6 μ g/ml时，才发现超高亲和力结合位点。当剂量增加到10 μ g/kg时，几乎消失。这些体外和体内的结果表明，体内和体外的实际游离配体浓度之间存在显著差异，并且完整脑中的浓度可能远低于先前认为的。少

Bio-Imaging Analyzer System with imaging plate was recently developed and possesses with ultra high sensitivity, high resolution and a wide dynamic range compared with X-ray films. Taking advantages of the Bio-Imaging Analyzer System, we examined the possibility of applying this system for functional imaging in living brain slices. Whole brain slices of 300 mum thickness were incubated with radiolabeled compounds. The slices were then rinsed and placed on the bottom of a Plexiglas chamber filled with Krebs.Ringer solution. The bottom of the chamber consisted of a thin polypropylene film to allow good penetration of radiation from the brain slices. The chamber was placed on a imaging plate. After exposure, the imaging plate was scanned by the Bio-Imaging Analyzer System and radioactivity images of brain slices were obtained. By using this system, we evaluated the glucose metabolism changes under hypoxic condition and the super high affinity binding sites in rat hippocampus for [3-H]Ro 1 … More 5-4513, a partial inverse agonist of central benzodiazepine receptors. Under hypoxic condition, increase of radioactivity of [14-C]glucose was observed in all brain regions compared with the control group. Differences of increase rate of rdioactivity uptake between brain regions were also observed. These results suggested that utilization rate of glucose increase due to acceleration of anaerobic metabolism and that energy demands vary depending on the brain regions under hypoxic condition compared with control group. On the other hand, in vitro binding of [3-H]Ro15-4513, the supar high affinity binding sites in the hippocampus were observed when the [3-H]Ro15-4513 concentration was below 0.5 nM.In vivo, the supar high affinity binding sites were only found when the injected dose of Ro15-4513 was below 3.6 mug/kg and almost disappeared when the dose was increased to 10 mug/kg. These results both in vitro and in vivo indicate that there is a significant discrepancy between actual free ligand concentration in vivo and in vitro, and that concntration in intact brain may be much lower than previously thought. Less