Department of Neuroscience, Psychology, Division of Pharmacology and Toxicology, Drug Research and Child Health (NEUROFARBA), Firenze, Italy.
Department of Experimental and Clinical Medicine, Section of Human Anatomy and Histology, University of Florence, Florence, Italy.
J Neurochem. 2021 May;157(4):1182-1195. doi: 10.1111/jnc.15209. Epub 2020 Oct 27.
The Nucleus Basalis of Meynert (NBM) is the main source of cholinergic neurons in the basal forebrain to be crucially involved in cognitive functions and whose degeneration correlates with cognitive decline in major degenerative pathologies as Alzheimer's and Parkinson's diseases. However, knowledge concerning NBM neurons derived from human brain is very limited to date. We recently characterized a primary culture of proliferating neuroblasts isolated from the human fetal NBM (hfNBM) as immature cholinergic neurons expressing the machinery to synthetize and release acetylcholine. Here we studied in detail electrophysiological features and cholinergic effects in this cell culture by patch-clamp recordings. Our data demonstrate that atropine-blocked muscarinic receptor activation by acetylcholine or carbachol enhanced I and reduced I currents by stimulating G -coupled M2 or phospholipase C-coupled M3 receptors, respectively. Inhibition of acetylcholine esterase activity by neostigmine unveiled a spontaneous acetylcholine release from hfNBM neuroblasts that might account for an autocrine/paracrine signaling during human brain development. Present data provide the first description of cholinergic effects in human NBM neurons and point to a role of acetylcholine as an autocrine/paracrine modulator of voltage-dependent channels. Our research could be of relevance in understanding the mechanisms of cholinergic system development and functions in the human brain, either in health or disease.
基底前脑核(NBM)是基底前脑胆碱能神经元的主要来源,对认知功能至关重要,其退化与阿尔茨海默病和帕金森病等主要退行性疾病的认知能力下降相关。然而,目前关于源自人类大脑的 NBM 神经元的知识非常有限。我们最近对从人胎脑 NBM(hfNBM)中分离出的增殖神经母细胞的原代培养进行了表征,发现其为表达合成和释放乙酰胆碱的机制的未成熟胆碱能神经元。在这里,我们通过膜片钳记录详细研究了该细胞培养物中的电生理特征和胆碱能效应。我们的数据表明,毒蕈碱受体激动剂乙酰胆碱或卡巴胆碱通过刺激 G 偶联 M2 或磷脂酶 C 偶联 M3 受体,分别增强了 I 和降低了 I 电流,从而阻断了毒蕈碱受体的激活。新斯的明抑制乙酰胆碱酯酶的活性揭示了 hfNBM 神经母细胞中自发的乙酰胆碱释放,这可能解释了人类大脑发育过程中的自分泌/旁分泌信号。目前的数据首次描述了人 NBM 神经元中的胆碱能效应,并指出乙酰胆碱作为电压依赖性通道的自分泌/旁分泌调节剂的作用。我们的研究可能有助于理解人类大脑中胆碱能系统发育和功能的机制,无论是在健康还是疾病状态下。