Beltramo M, Krieger M, Tillet Y, Thibault J, Calas A, Mazzi V, Franzoni M F
Laboratoire de Cytologie, CNRS URA 1488, Université Paris VI, France.
J Comp Neurol. 1994 May 8;343(2):209-27. doi: 10.1002/cne.903430203.
The distribution of monoamines (catecholamines and serotonin) in fishes has been previously studied by immunohistochemistry of both the monoamines themselves and their biosynthetic enzymes. But the distribution of neurons containing aromatic L-amino acid decarboxylase, an enzyme involved in the biosynthesis of both catecholamines and serotonin, has up to now not been investigated. In order to improve knowledge about the localization of aromatic L-amino acid decarboxylase, neurons containing this enzyme were mapped immunohistochemically in the goldfish brain. Furthermore, neurons bearing aromatic L-amino acid decarboxylase immunoreactivity have been compared with those containing tyrosine hydroxylase and serotonin immunoreactivities. Our results show that distribution of aromatic L-amino acid decarboxylase immunoreactivity generally coincides with that of tyrosine hydroxylase and serotonin. Nevertheless, the presence of nine D cell groups (containing aromatic L-amino acid decarboxylase but lacking both catecholamines and serotonin) and six groups of neurons which are aromatic L-amino acid decarboxylase-immunonegative but contain tyrosine hydroxylase, and might produce L-DOPA, have been revealed. The occurrence of both D cell groups and presumptive L-DOPA neurons in goldfish brain is discussed in relation to similar findings in fish and mammalian brain.
此前已通过对单胺类物质（儿茶酚胺和5-羟色胺）自身及其生物合成酶进行免疫组织化学研究，探究了鱼类中单胺类物质的分布情况。但截至目前，尚未对含有芳香族L-氨基酸脱羧酶（一种参与儿茶酚胺和5-羟色胺生物合成的酶）的神经元分布进行研究。为了增进对芳香族L-氨基酸脱羧酶定位的了解，采用免疫组织化学方法对金鱼脑中含有该酶的神经元进行了定位。此外，还将含有芳香族L-氨基酸脱羧酶免疫反应性的神经元与含有酪氨酸羟化酶和5-羟色胺免疫反应性的神经元进行了比较。我们的结果表明，芳香族L-氨基酸脱羧酶免疫反应性的分布通常与酪氨酸羟化酶和5-羟色胺的分布一致。然而，已发现存在9个D细胞群（含有芳香族L-氨基酸脱羧酶，但既缺乏儿茶酚胺也缺乏5-羟色胺）以及6组神经元，这些神经元对芳香族L-氨基酸脱羧酶免疫阴性，但含有酪氨酸羟化酶，可能产生左旋多巴。结合在鱼类和哺乳动物脑中的类似发现，对金鱼脑中D细胞群和假定的左旋多巴能神经元的存在情况进行了讨论。
