Kalivas P W, Jennes L, Miller J S
Brain Res. 1985 Feb 11;326(2):229-38. doi: 10.1016/0006-8993(85)90032-0.
The ventral tegmental area contains a high density of dopaminergic perikarya having ascending projections to a number of limbic forebrain regions. In this study, we use combined retrograde labeling with horseradish peroxidase (HRP) and immunohistochemical staining for tyrosine hydroxylase to examine the catecholaminergic projection from the ventral tegmental area to the diagonal band of Broca. When injection of HRP was restricted to the diagonal band, only neurons in the nucleus linearis, nucleus interfascicularis and ventromedial portion of the nucleus paranigralis were labeled. In contrast, HRP injection into the adjacent nucleus accumbens labeled neurons throughout these nuclei, plus the nucleus parabrachialis pigmentosus, nucleus retroruber and substantia nigra, pars compacta. Approximately 60% of neurons in the ventral tegmental area labeled from the diagonal band contained tyrosine hydroxylase, compared with 79% of the neurons labeled from the nucleus accumbens. Neurotensin is a tridecapeptide found in the ventral tegmental area which has been shown to activate dopamine neurons projecting to the nucleus accumbens. In this study, microinjection of neurotensin into ventral tegmental nuclei which contained neurons retrogradely labeled from the diagonal band significantly elevated the levels of dopamine metabolites, 3,4-dihydroxyphenylacetic acid and homovanillic acid, in the diagonal band. The results of this study demonstrate that a catecholaminergic projection exists from the ventral tegmental area to the diagonal band of Broca, and that this pathway can be stimulated by intra-ventral tegmental injection with neurotensin.
腹侧被盖区含有高密度的多巴胺能神经元胞体，这些胞体向多个边缘前脑区域发出上行投射。在本研究中，我们采用辣根过氧化物酶（HRP）逆行标记与酪氨酸羟化酶免疫组织化学染色相结合的方法，来研究从腹侧被盖区到布罗卡斜带的儿茶酚胺能投射。当将HRP注射局限于斜带时，仅线性核、束间核和黑质旁核腹内侧部分的神经元被标记。相反，将HRP注射到相邻的伏隔核，则标记了这些核内的所有神经元，以及臂旁色素核、红核后核和黑质致密部。从斜带标记的腹侧被盖区神经元中，约60%含有酪氨酸羟化酶，而从伏隔核标记的神经元中这一比例为79%。神经降压素是一种在腹侧被盖区发现的十三肽，已被证明可激活投射到伏隔核的多巴胺能神经元。在本研究中，向含有从斜带逆行标记神经元的腹侧被盖核微量注射神经降压素，可显著提高斜带中多巴胺代谢产物3,4-二羟基苯乙酸和高香草酸水平。本研究结果表明，存在一条从腹侧被盖区到布罗卡斜带的儿茶酚胺能投射，并且该通路可通过腹侧被盖区内注射神经降压素而被激活。
