Consolo S, Bertorelli R, Forloni G L, Butcher L L
Laboratory of Cholinergic Neuropharmacology, Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy.
Neuroscience. 1990;37(3):717-23. doi: 10.1016/0306-4522(90)90102-a.
Two major systems of cholinergic projection neurons are found within the centrum of the mammalian brain: the basal nuclear complex, projecting predominantly to the cerebral cortex, amygdala, and hippocampus, and the pontomesencephalotegmental network, innervating primarily the thalamus. Neurons comprising the latter network also project to the basal forebrain, but the functional properties of that fiber connection, if any, are unknown. In an attempt to address this issue, the extracellular concentration of acetylcholine was measured in the basal nuclear complex of freely moving rats, both singularly and in combination with lesions and pharmacologic manipulations. Acetylcholine release monitored in the presence of physostigmine sulfate in the basal forebrain was (a) calcium-dependent, (b) increased by systemic scopolamine injection, the rise persisting in the presence of quisqualate lesions of the basal nuclear complex, (c) blocked by tetrodotoxin, and (d) abolished by ablation of cell bodies in the pontomesencephalic tegmentum, which also produced a decrease of choline acetyltransferase activity in the nucleus basalis/substantia innominata region, but not by quisqualate lesions of the basal forebrain. It is concluded from these data that the calcium-dependent release of acetylcholine in the basal nuclear complex (a) is largely axonal in nature, (b) derives substantially from axons of the cholinergic pontomesencephalic tegmentum, and (c) appears to be controlled by presynaptic muscarinic receptors on axon terminals of the latter system. The pontomesencephalotegmental cholinergic complex might thus influence cortical acetylcholine release, in part at least, by means of serial-order cholinergic-cholinergic interactions in the basal nuclear complex.
基底核复合体，主要投射至大脑皮层、杏仁核和海马体；脑桥中脑被盖网络，主要支配丘脑。构成后一网络的神经元也投射至基底前脑，但该纤维连接（若存在）的功能特性尚不清楚。为解决这一问题，对自由活动大鼠基底核复合体内乙酰胆碱的细胞外浓度进行了单独测量，并结合损伤和药理学操作进行了测量。在基底前脑存在硫酸毒扁豆碱的情况下监测到的乙酰胆碱释放具有以下特点：（a）依赖钙；（b）全身注射东莨菪碱后增加，在基底核复合体存在喹啉酸损伤时该升高持续存在；（c）被河豚毒素阻断；（d）脑桥中脑被盖区细胞体切除后消失，这也导致基底核/无名质区域胆碱乙酰转移酶活性降低，但基底前脑的喹啉酸损伤并未导致该现象。从这些数据得出的结论是，基底核复合体内乙酰胆碱的钙依赖性释放：（a）在很大程度上是轴突性的；（b）主要源自胆碱能脑桥中脑被盖区的轴突；（c）似乎受后一系统轴突终末上的突触前毒蕈碱受体控制。因此，脑桥中脑被盖胆碱能复合体可能至少部分地通过基底核复合体内的序列性胆碱能 - 胆碱能相互作用来影响皮层乙酰胆碱的释放。
