Falk Lena, Nordberg Agneta, Seiger Ake, Kjaeldgaard Anders, Hellström-Lindahl Ewa
Department of Clinical Neuroscience, Occupational Therapy and Elderly Care Research, Karolinska Institutet, Huddinge University Hospital, Stockholm, Sweden.
J Neurochem. 2002 Feb;80(3):457-65. doi: 10.1046/j.0022-3042.2001.00714.x.
The alpha7 nicotinic acetylcholine receptor subtype is believed to be involved in the regulation of neuronal growth, differentiation and synapse formation during the development of the human brain. In this study the expression of the alpha7 nicotinic acetylcholine receptor was investigated in human fetal brain and spinal cord of 5-11 weeks gestational age. Both the specific binding of [125I]alpha-bungarotoxin to prenatal brain membranes and the expression of alpha7 mRNA were significantly higher in the pons, medulla oblongata, mesencephalon and spinal cord of 9-11 weeks gestational age compared with cerebellum, cortex and subcortical forebrain. A significant positive correlation between gestational age and the expression of alpha7 mRNA was observed in all brain regions except cortex. A positive correlation was also observed between the gestational age and the [125I]alpha-bungarotoxin binding in the pons, medulla oblongata, mesencephalon, and cerebellum. Consequently, a significant relationship between the alpha7 mRNA levels and the binding sites for [125I]alpha-bungarotoxin was found in the fetal brain. The increasing levels of the alpha7 nicotinic acetylcholine receptor during the first trimester support the important role of nAChRs for the development of the central nervous system.
α7烟碱型乙酰胆碱受体亚型被认为在人类大脑发育过程中参与神经元生长、分化及突触形成的调节。在本研究中，对孕龄5 - 11周的人类胎儿脑和脊髓中α7烟碱型乙酰胆碱受体的表达进行了研究。与小脑、皮质及皮质下前脑相比，孕龄9 - 11周的脑桥、延髓、中脑和脊髓中，[125I]α - 银环蛇毒素与产前脑膜的特异性结合以及α7 mRNA的表达均显著更高。除皮质外，在所有脑区均观察到孕龄与α7 mRNA表达之间存在显著正相关。在脑桥、延髓、中脑和小脑中，也观察到孕龄与[125I]α - 银环蛇毒素结合之间存在正相关。因此，在胎儿脑中发现α7 mRNA水平与[125I]α - 银环蛇毒素结合位点之间存在显著关系。孕早期α7烟碱型乙酰胆碱受体水平的升高支持了烟碱型乙酰胆碱受体对中枢神经系统发育的重要作用。
