Abstract：
We examined the presence/absence and parcellation of cholinergic neurons in the hypothalami of five birds: a Congo grey parrot (Psittacus erithacus), a Timneh grey parrot (P. timneh), a pied crow (Corvus albus), a common ostrich (Struthio camelus), and an emu (Dromaius novaehollandiae). Using immunohistochemistry to an antibody raised against the enzyme choline acetyltransferase, hypothalamic cholinergic neurons were observed in six distinct clusters in the medial, lateral, and ventral hypothalamus in the parrots and crow, similar to prior observations made in the pigeon. The expression of cholinergic nuclei was most prominent in the Congo grey parrot, both in the medial and lateral hypothalamus. In contrast, no evidence of cholinergic neurons in the hypothalami of either the ostrich or emu was found. It is known that the expression of sleep states in the ostrich is unusual and resembles that observed in the monotremes that also lack hypothalamic cholinergic neurons. It has been proposed that the cholinergic system acts globally to produce and maintain brain states, such as those of arousal and rapid-eye-movement sleep. The hiatus in the cholinergic system of the ostrich, due to the lack of hypothalamic cholinergic neurons, may explain, in part, the unusual expression of sleep states in this species. These comparative anatomical and sleep studies provide supportive evidence for global cholinergic actions and may provide an important framework for our understanding of one broad function of the cholinergic system and possible dysfunctions associated with global cholinergic neural activity.
摘要：
我们检查了五只鸟下丘脑中胆碱能神经元的存在/不存在和分裂：刚果灰鹦鹉（Psittacuserithacus），一只Timneh灰色鹦鹉(P.timneh),一只斑驳的乌鸦（Corvusalbus），一种常见的鸵鸟（Struthiocamelus），和emu（Dromaiusnovaehollandiae）。使用免疫组织化学对针对胆碱乙酰转移酶产生的抗体，下丘脑胆碱能神经元在中间观察到六个不同的簇，横向,鹦鹉和乌鸦的腹侧下丘脑，类似于先前对鸽子的观察。胆碱能核的表达在刚果灰鹦鹉中最为突出，在下丘脑内侧和外侧。相比之下,在鸵鸟或emu的下丘脑中没有发现胆碱能神经元的证据。众所周知，鸵鸟中睡眠状态的表达是不寻常的，并且类似于在也缺乏下丘脑胆碱能神经元的单调中观察到的表达。有人提出胆碱能系统在全球范围内产生和维持大脑状态，例如唤醒和快速眼动睡眠。鸵鸟胆碱能系统的裂口，由于下丘脑胆碱能神经元的缺乏，可以解释，在某种程度上,该物种睡眠状态的不寻常表达。这些比较解剖学和睡眠研究为全球胆碱能作用提供了支持性证据，并且可能为我们了解胆碱能系统的一种广泛功能以及与全球胆碱能神经活动相关的可能功能障碍提供了重要框架。
