Heise Claire E, Mitrofanis John
Department of Anatomy and Histology, University of Sydney, New South Wales 2006, Australia.
J Comp Neurol. 2004 Jan 19;468(4):482-95. doi: 10.1002/cne.10971.
This study explores the organisation and neurochemical nature of the projections from the zona incerta (ZI) to the basal ganglia. Sprague-Dawley rats were anaesthetised with ketamine (100 mg/kg) and Rompun (10 mg/kg), and injections of cholera toxin subunit B were made into each of the following nuclei: the ZI, the substantia nigra (SN), the pedunculopontine tegmental nucleus (PpT), and the entopeduncular nucleus (Ep). Brains were aldehyde fixed, sectioned, and processed using standard methods. Tracer-labelled sections were then doubly labelled with antibodies to glutamate (Glu), nitric oxide synthase (NOS), parvalbumin (Pv), or glutamic acid decarboxylase (GAD; the latter two are markers for GABAergic cells); these neurochemicals characterise most types of ZI cells. After ZI injections, labelling was nonuniform across the different basal ganglia nuclei. The bulk of labelling, both anterograde and retrograde, was seen in the SN and PpT and, to a lesser extent, within the other nuclei of the basal ganglia (e.g., caudate-putamen, globus pallidus, subthalamus, Ep). In the SN, labelling was found in both major parts of the nucleus, the pars compacta and pars reticulata. Within the PpT, however, the bulk of labelling was limited to only one of the two sectors of the nucleus, namely, the pars dissipata (PpTd). The pars compacta of the PpT (PpTc) remained largely free of labelled profiles. After CTb injections into three basal ganglia nuclei (SN, PpT, Ep), most labelled cells in the ZI were glutamate+ and very few were NOS+ or gamma-aminobutyric acidergic. Overall, the results indicate that the ZI is in a position to influence preferentially the activity of the SN and PpTd of the basal ganglia via an excitatory, glutamatergic input.
本研究探讨了未定带（ZI）至基底神经节投射的组织学及神经化学性质。将Sprague-Dawley大鼠用氯胺酮（100mg/kg）和隆朋（10mg/kg）麻醉，然后向以下各核注射霍乱毒素B亚单位：ZI、黑质（SN）、脚桥被盖核（PpT）和内苍白球核（Ep）。大脑用醛类固定、切片，并采用标准方法处理。然后，用针对谷氨酸（Glu）、一氧化氮合酶（NOS）、小白蛋白（Pv）或谷氨酸脱羧酶（GAD；后两者是GABA能细胞的标志物）的抗体对示踪剂标记的切片进行双重标记；这些神经化学物质可表征大多数类型的ZI细胞。在向ZI注射后，不同基底神经节核内的标记并不均匀。大部分顺行和逆行标记见于SN和PpT，在较小程度上见于基底神经节的其他核（如尾状核-壳核、苍白球、底丘脑、Ep）。在SN中，标记见于核的两个主要部分，即致密部和网状部。然而，在PpT内，大部分标记仅限于核的两个区域之一，即分散部（PpTd）。PpT的致密部（PpTc）基本没有标记轮廓。在向三个基底神经节核（SN、PpT、Ep）注射霍乱毒素B（CTb）后，ZI中大多数标记细胞为谷氨酸能阳性，很少有一氧化氮合酶阳性或γ-氨基丁酸能阳性。总体而言，结果表明ZI能够通过兴奋性谷氨酸能输入优先影响基底神经节的SN和PpTd的活动。
