Dubé L, Parent A
J Comp Neurol. 1981 Mar 10;196(4):695-708. doi: 10.1002/cne.901960413.
The distribution of monoamine (MA)-containing nerve cell bodies in the brain stem of the chicken (Gallus domesticus) was studied by means of paraformaldehyde and glyoxylic acid fluorescent histochemical methods. The MA neurons were further characterized morphologically and histochemically in material prepared for the demonstration of acetylcholinesterase (AChE). In the rostral midbrain of the chicken, two large collections of catecholamine (CA)-containing cells are found: one located in the ventromedial and the other in the dorsolateral (pedunculopontine nucleus) portions of the tegmentum. On the basis of their topographic location, CA content, and fiber connections, these ventromedial and dorsolateral cell groups can be tentatively associated with the CA-containing neuronal populations of the mammalian ventral tegmental area and pars compacta of the substantia nigra, respectively. In the caudal midbrain of the chicken, numerous CA-containing cells are intermingled with serotonin (5HT)-containing perikarya beneath as well as within the decussation of the superior cerebellar peduncles. At isthmus levels, abundant, closely-packed CA-containing cells are encountered along the lateral border of the central gray. These neurons, which display a very high AChE activity, appear to be equivalent to those of the mammalian locus coeruleus. A multitude of medium-sized 5HT-containing neuronal somata occurs within the raphe region of the isthmus. Some of these somata closely surround the medial longitudinal fasciculus. This 5HT-containing cell group also massively invades the lateral tegmentum, where it becomes closely intermingled with the CA-containing neurons of the locus coeruleus and subcoeruleus. All of these 5 HT-containing neurons display a moderate to high AChE activity. In the medulla the number of MA-containing neurons is much smaller than in the upper brain stem. Nevertheless, 5HT-containing cells are present within the raphe region, particularly in the upper two-thirds of the medulla, and CA-containing perikarya can be found along the lateral border of the medulla and within the confines of the nucleus solitarius. The findings of the present study reveal that the MA-containing neuronal systems in the avian brain stem are organized according to a pattern that is much more complex than the one disclosed in reptiles or in other nonmammalian vertebrates. This complexity arises in large part from the fact that the 5HT-containing systems undergo a prominent lateralization in birds, which leads to a close intermingling of 5HT-containing and CA-containing neuronal elements at various levels of the neuraxis.
采用多聚甲醛和乙醛酸荧光组织化学方法，研究了家鸡（Gallus domesticus）脑干中含单胺（MA）神经细胞体的分布情况。在用于显示乙酰胆碱酯酶（AChE）的材料中，对MA神经元进行了进一步的形态学和组织化学特征分析。在家鸡的中脑前部，发现了两大群含儿茶酚胺（CA）的细胞：一群位于被盖腹内侧部，另一群位于被盖背外侧部（脚桥核）。根据它们的地形位置、CA含量和纤维连接，这些腹内侧和背外侧细胞群可分别初步与哺乳动物腹侧被盖区和黑质致密部的含CA神经元群体相关联。在家鸡的中脑后部，大量含CA的细胞与含5-羟色胺（5HT）的核周体在小脑上脚交叉下方及交叉内相互交织。在峡部水平，沿中央灰质外侧缘可见大量紧密排列的含CA细胞。这些神经元显示出非常高的AChE活性，似乎等同于哺乳动物的蓝斑神经元。在峡部缝际区有大量中等大小的含5HT神经元胞体。其中一些胞体紧密围绕内侧纵束。这个含5HT细胞群也大量侵入外侧被盖区，在那里它与蓝斑和蓝斑下核的含CA神经元紧密交织在一起。所有这些含5HT的神经元都显示出中度到高度的AChE活性。在延髓中，含MA的神经元数量比上脑干中的要少得多。然而，含5HT的细胞存在于缝际区，特别是在延髓的上三分之二部分，含CA的核周体可在延髓外侧缘和孤束核范围内找到。本研究结果表明，鸟类脑干中含MA的神经元系统的组织模式比爬行动物或其他非哺乳动物脊椎动物中所揭示的模式要复杂得多。这种复杂性在很大程度上源于这样一个事实，即含5HT的系统在鸟类中发生了显著的侧向化，这导致在神经轴的不同水平上，含5HT和含CA的神经元成分紧密交织在一起。
