Koh S, Loy R
Department of Neurobiology and Anatomy, University of Rochester Medical Center, NY 14642.
Brain Res. 1988 Feb 9;440(2):396-401. doi: 10.1016/0006-8993(88)91015-3.
Nerve growth factor (NGF) has recently been implicated as a trophic agent in the survival and maintenance of basal forebrain cholinergic neurons. To test the hypothesis that NGF may play a role in the age-related degeneration of basal forebrain neurons and decline of cerebral cholinergic function, we have used a monoclonal antibody to the NGF receptor, 192 IgG, to immunocytochemically visualize and compare rat basal forebrain neurons responsive to NGF in aged (30 months) and young adult (10 months) rats. In a subpopulation of aged rats, NGF receptor-immunoreactive cells in the basal forebrain appear vacuolated and shrunken, and the neuropil staining is markedly reduced. While no substantial decline in cell density is apparent in Nissl-stained sections, the number of NGF receptor-positive cell profiles within the vertical limb of diagonal band nuclei is reduced by an average of 32% in aged rats. Marked reduction in the expression of NGF receptors in aged rats may signify loss of capacity of the basal forebrain neurons to bind and transport NGF from their terminals in the hippocampus and cortex, subsequent decrease in NGF delivered to the cell bodies, and eventual cellular dysfunction and death of neurons in aging.
神经生长因子（NGF）最近被认为是一种营养因子，对基底前脑胆碱能神经元的存活和维持起作用。为了验证NGF可能在基底前脑神经元的年龄相关性退变及脑胆碱能功能衰退中发挥作用这一假说，我们使用了一种针对NGF受体的单克隆抗体192 IgG，通过免疫细胞化学方法来可视化并比较老年（30个月）和年轻成年（10个月）大鼠中对NGF有反应的基底前脑神经元。在一部分老年大鼠中，基底前脑内NGF受体免疫反应阳性细胞出现空泡化和萎缩，神经毡染色明显减少。虽然在尼氏染色切片中细胞密度没有明显下降，但老年大鼠中斜角带核垂直支内NGF受体阳性细胞轮廓的数量平均减少了32%。老年大鼠中NGF受体表达的显著降低可能意味着基底前脑神经元从海马体和皮质的终末结合并转运NGF的能力丧失，随后输送到细胞体的NGF减少，最终导致衰老过程中神经元的细胞功能障碍和死亡。
