Landis S C
Fed Proc. 1983 Apr;42(6):1633-8.
Most principal neurons in sympathetic ganglia are noradrenergic. A small population, especially those that innervate sweat glands in rat footpads, are cholinergic. We have characterized the innervation of the glands in adult and developing rats to determine whether sympathetic neurons undergo a transition from noradrenergic to cholinergic during normal development as has been observed in culture. In adult rats, the fibers innervating sweat glands exhibited strong acetylcholinesterase (AChE) staining and vasoactive intestinal peptide (VIP)-like immunoreactivity. None of the axons contained endogenous catecholamines detectable with formaldehyde-induced fluorescence or permanganate fixation. However, like cholinergic sympathetic neurons in culture, all axons could take up and store exogenous catecholamine. The sweat glands and their innervation develop postnatally. At 7 days, the axons innervating sweat glands possessed endogenous catecholamine histofluorescence and small granular vesicles but not AChE or VIP. By 14 days, AChE and VIP staining was pronounced. In contrast, catecholamine fluorescence and the number of small granular vesicles were reduced, and by 21 days they were absent. Further, neonatal treatment with 6-hydroxydopamine, a toxic norepinephrine congener, resulted in the loss of cholinergic as well as noradrenergic sympathetic innervation. These observations are consistent with a transition from noradrenergic to cholinergic function in vivo.
交感神经节中的大多数主要神经元是去甲肾上腺素能的。一小部分神经元，尤其是那些支配大鼠脚垫汗腺的神经元，是胆碱能的。我们对成年和发育中的大鼠汗腺的神经支配进行了特征描述，以确定交感神经元在正常发育过程中是否会像在培养中观察到的那样经历从去甲肾上腺素能到胆碱能的转变。在成年大鼠中，支配汗腺的纤维表现出强烈的乙酰胆碱酯酶（AChE）染色和血管活性肠肽（VIP）样免疫反应性。没有轴突含有可通过甲醛诱导荧光或高锰酸盐固定检测到的内源性儿茶酚胺。然而，与培养中的胆碱能交感神经元一样，所有轴突都可以摄取和储存外源性儿茶酚胺。汗腺及其神经支配在出生后发育。在7天时，支配汗腺的轴突具有内源性儿茶酚胺组织荧光和小颗粒囊泡，但没有AChE或VIP。到14天时，AChE和VIP染色明显。相比之下，儿茶酚胺荧光和小颗粒囊泡的数量减少，到21天时它们消失了。此外，用有毒的去甲肾上腺素类似物6-羟基多巴胺对新生大鼠进行治疗，导致胆碱能和去甲肾上腺素能交感神经支配丧失。这些观察结果与体内从去甲肾上腺素能功能到胆碱能功能的转变一致。
