Otake K, Ruggiero D A
Department of Neurology and Neuroscience, Cornell University Medical College, New York, New York 10021.
J Neurosci. 1995 Mar;15(3 Pt 1):1891-911. doi: 10.1523/JNEUROSCI.15-03-01891.1995.
The neurochemical identities of afferents to the midline thalamus were investigated in chloral hydrate-anesthetized adult Sprague-Dawley rats. The retrograde tracers, FluoroGold or cholera toxin B subunit, were centered on the paraventricular thalamic nucleus (n.Pvt), a periventricular member of the diffuse thalamocortical projection system that is reciprocally linked with visceral areas of cerebral cortex and implicated in food intake and addictive behavior. Tissues were processed with antisera raised against 5-HT, the catecholamine-synthesizing enzymes, tyrosine hydroxylase or phenylethanolamine N-methyltransferase or the cholinergic anabolic enzyme, ChAT. Serotonergic afferents principally derive from dorsal and median constituents of the mesopontine raphé. Previously unrecognized sources of catecholaminergic afferents were detected. Adrenergic afferents were traced to neurons in the C1 and C3 areas of rostral medullary reticular formation and periventricular gray, respectively, and the C2 area corresponding to the dorsal general viscerosensory field of nucleus tractus solitarii. Noradrenergic afferents arise principally from neurons in the locus ceruleus and A5 area. Dopaminergic projections to the n.Pvt derive from the A14, A13 and A11 cell groups in diencephalon. Afferents presumed to generate nitric oxide (NO) as a diffusible membrane-permeant transcellular signal were detected by processing retrogradely labeled tissues histochemically for NADPH-diaphorase, a molecule associated with nitric oxide synthase. NO in the n.Pvt is generated predominantly by noncholinergic neurons in the lateral hypothalamic area and mesopontine tegmentum. In striking contrast, extensive interactions were predicted between NO and ACh in the central medial and other loci in the nondiscriminative thalamus. We conclude that the n.Pvt is a site of interaction of NO and monoaminergic afferents derived from nuclei implicated in sensory gating, regulation of electrocortical neural activity and behavior. Taken collectively, our data predict that the labile transcellular messenger NO may enable structurally differentiated subnuclei of the diffuse thalamocortical projection system to act in concert as a functionally unified unit.
在水合氯醛麻醉的成年Sprague-Dawley大鼠中，研究了丘脑中线传入神经的神经化学特性。逆行示踪剂氟金或霍乱毒素B亚单位，集中于丘脑室旁核（n.Pvt），它是弥漫性丘脑皮质投射系统的室周成员，与大脑皮质的内脏区域相互连接，并与食物摄入和成瘾行为有关。组织用针对5-羟色胺、儿茶酚胺合成酶、酪氨酸羟化酶或苯乙醇胺N-甲基转移酶或胆碱能合成酶ChAT的抗血清进行处理。5-羟色胺能传入神经主要来源于中脑桥缝核的背侧和中间成分。检测到了以前未被认识的儿茶酚胺能传入神经来源。肾上腺素能传入神经分别追溯到延髓头端网状结构的C1和C3区域以及室周灰质中的神经元，以及对应于孤束核背侧一般内脏感觉区的C2区域。去甲肾上腺素能传入神经主要起源于蓝斑和A5区域的神经元。向n.Pvt的多巴胺能投射来自间脑中的A14、A13和A11细胞群。通过对逆行标记的组织进行组织化学处理以检测NADPH-黄递酶（一种与一氧化氮合酶相关的分子），检测到推测产生一氧化氮（NO）作为可扩散的膜渗透跨细胞信号的传入神经。n.Pvt中的NO主要由下丘脑外侧区和中脑桥被盖中的非胆碱能神经元产生。与之形成鲜明对比的是，预测在丘脑中央内侧和其他非特异性丘脑区域中，NO和乙酰胆碱之间存在广泛的相互作用。我们得出结论，n.Pvt是NO与源自涉及感觉门控、电皮质神经活动调节和行为的核的单胺能传入神经相互作用的位点。综合来看，我们的数据预测，不稳定的跨细胞信使NO可能使弥漫性丘脑皮质投射系统结构上分化的亚核作为一个功能统一的单元协同作用。
