Spect Brain Imaging In Neuropsychiatric Disorders

单光子发射计算机断层扫描，SPECT，可以测量大脑中放射性示踪剂的三维分布。使用中的示踪剂主要分为两类。在第一类中，示踪剂在大脑中与血流量成比例，因此可以用作神经活动的标记物。第二类示踪剂与大脑中的神经递质受体结合，从而反映出相关神经化学的分布。虽然先前脑血流药物的工作在很大程度上是成功的，但现在存在其他更敏感的CBF测量方法。因此，SPECT成像已成为我们体内神经化学的首选方法。在临床人群中，我们对三种放射性配体进行了研究。这些药物包括多巴胺D2拮抗剂IBZM、多巴胺和血清素转运体拮抗剂β - cit和毒蕈碱拮抗剂QNB。我们使用这些放射配体来检查无药精神分裂症患者神经化学功能的临床相关性，并进一步阐明抗精神病药物的作用机制。我们还完成了多巴胺能和血清素能在抽动秽语综合征和酒精依赖患者中的功能研究。在非人类灵长类动物的研究中，我们用这些配体测试了人类神经精神疾病模型的神经化学功能。我们还进行了非人类灵长类动物研究，以开发新的放射配体。其中包括TISCH，一种多巴胺D1受体拮抗剂，DOI，一种5 -羟色胺5HT2激动剂。

Single photon emission computed tomography, SPECT, allows for the measurement of the 3-D distribution of radioactive tracers in brain. Tracers in use fall into two main classes. In the first class, the tracer is taken up in brain in proportion to blood flow and thus can be utilized as a marker of neural activity. The second class of tracers binds to neurotransmitter receptors in brain such that the activity then reflects the distribution of the related neurochemistry. While previous work with cerebral blood flow agents was largely successful, other more sensitive means now exist for CBF measurements. Therefore, SPECT imaging has become our procedure of choice for in vivo neurochemistry. In clinical populations, we have performed studies with three radioligands. These include the dopamine D2 antagonist IBZM, the dopamine and serotonin transporter antagonist beta-CIT, and the muscarinic antagonist QNB. We have used these radioligands to examine clinical correlates of neurochemical function in drug- free schizophrenic patients, and to further elucidate the mechanism of action of neuroleptic drugs. We have also completed studies of dopaminergic and serotonergic function in patients with Tourette's syndrome and alcohol dependence. In non-human primate studies with these ligands we have tested neurochemical function in models of human neuropsychiatric illness. We have also conducted non-human primate studies to develop new radioligands. These include TISCH, a dopamine D1 receptor antagonist, and DOI, a serotonin 5HT2 agonist.