Kitchener P D, Diamond J
Department of Biomedical Sciences, McMaster University, Hamilton Ontario, Canada.
J Comp Neurol. 1993 Sep 1;335(1):1-15. doi: 10.1002/cne.903350102.
NADPH diaphorase histochemistry and choline acetyltransferase immunocytochemistry were used to assess quantitatively the presence of nitric oxide synthase in the cholinergic neurons of the magnocellular basal forebrain complex. Virtually all (97%) NADPH diaphorase reactive magnocellular neurons in the medial septum and the vertical and horizontal limbs of the diagonal band of Broca were choline acetyltransferase immunoreactive, whereas only a proportion of the choline acetyltransferase immunoreactive neurons were NADPH diaphorase reactive. Thus NADPH diaphorase histochemistry identified a subpopulation of the magnocellular cholinergic neurons. Occasionally, NADPH diaphorase reactive neurons were observed within the medial septum and diagonal band of Broca that were not choline acetyltransferase immunoreactive, and in general were morphologically distinct from the magnocellular neurons; such neurons are probably representatives within the medial septum and diagonal band of more widely distributed phenotypically distinct populations of NADPH diaphorase reactive neurons. The proportions of the neurons in which choline acetyltransferase and NADPH diaphorase colocalized in the medial septum and in the diagonal bands of Broca were similar in any one coronal section, but there was a considerable difference in the proportions throughout the rostrocaudal extent of these nuclei. In the most rostral sections of the medial septum and diagonal band, approximately 70% of the choline acetyltransferase immunoreactive neurons were NADPH diaphorase reactive, whereas the proportion decreased progressively to about 30% at the level of the decussation of the anterior commissure. To examine further the extent of colocalization throughout the magnocellular basal forebrain complex, sections of the magnocellular preoptic nucleus, substantia innominata, and nucleus basalis magnocellularis were examined. While there was little total colocalization of choline acetyltransferase immunoreactivity and NADPH diaphorase reactivity in any particular section (approximately 18%), almost all of the double labelled neurons were in the substantia innominata, with very few in the other nuclei. Thus although there is a caudal to rostral gradient of the proportion of magnocellular cholinergic neurons that are NADPH diaphorase reactive throughout the entire basal forebrain magnocellular complex, subregions, such as the substantia innominata and magnocellular preoptic nucleus, may not follow this trend. The recent demonstration that the NADPH diaphorase histochemical reaction localizes a nitric oxide synthase suggests that attention should be given to the NADPH diaphorase subpopulation in pathological and experimentally induced alterations of the basal forebrain.
采用NADPH黄递酶组织化学和胆碱乙酰转移酶免疫细胞化学方法，对大细胞基底前脑复合体胆碱能神经元中一氧化氮合酶的存在情况进行定量评估。实际上，内侧隔核以及布罗卡斜带垂直支和水平支中所有（97%）NADPH黄递酶反应性大细胞神经元均为胆碱乙酰转移酶免疫反应性神经元，而只有一部分胆碱乙酰转移酶免疫反应性神经元是NADPH黄递酶反应性的。因此，NADPH黄递酶组织化学鉴定出了大细胞胆碱能神经元的一个亚群。偶尔会在内侧隔核和布罗卡斜带中观察到一些NADPH黄递酶反应性神经元，它们并非胆碱乙酰转移酶免疫反应性的，并且在形态上通常与大细胞神经元不同；这类神经元可能是内侧隔核和斜带中分布更为广泛的表型不同的NADPH黄递酶反应性神经元群体的代表。在任何一个冠状切片中，内侧隔核和布罗卡斜带中胆碱乙酰转移酶和NADPH黄递酶共定位的神经元比例相似，但在这些核的整个前后范围内，比例存在相当大的差异。在内侧隔核和斜带最靠前的切片中，约70%的胆碱乙酰转移酶免疫反应性神经元是NADPH黄递酶反应性的，而在前连合交叉水平，这一比例逐渐降至约30%。为了进一步研究整个大细胞基底前脑复合体中的共定位程度，对大细胞视前核、无名质和大细胞基底核的切片进行了检查。虽然在任何特定切片中胆碱乙酰转移酶免疫反应性和NADPH黄递酶反应性的总共定位很少（约18%），但几乎所有双标记神经元都在无名质中，其他核中很少。因此，尽管在整个基底前脑大细胞复合体中，NADPH黄递酶反应性的大细胞胆碱能神经元比例存在从尾端到前端的梯度变化，但无名质和大细胞视前核等亚区域可能并不遵循这一趋势。最近的研究表明，NADPH黄递酶组织化学反应可定位一氧化氮合酶，这提示在基底前脑的病理和实验诱导改变中，应关注NADPH黄递酶亚群。
