Benowitz L I, Apostolides P J, Perrone-Bizzozero N, Finklestein S P, Zwiers H
Mailman Research Center, McLean Hospital, Belmont, Massachusetts 02178.
J Neurosci. 1988 Jan;8(1):339-52. doi: 10.1523/JNEUROSCI.08-01-00339.1988.
GAP-43 (B-50,F1,pp46) is a neuron-specific phosphoprotein that has been implicated in the development and modulation of synaptic relationships. Although most neurons cease expressing high levels of GAP-43 after the completion of synaptogenesis (Jacobson et al., 1986), certain brain regions continue to have considerable amounts of the protein throughout life (Oestreicher et al., 1986); in at least one such area, the phosphorylation of the protein has been linked with the events that underlie synaptic potentiation (Lovinger et al., 1985). In this study, we used the indirect immunoperoxidase method to map the distribution of GAP-43/B-50 in the brains of 8 adult rats with 2 different antibodies: a monospecific, polyclonal antibody prepared in sheep against the purified protein and an affinity-purified IgG prepared in rabbits. Specific immunoreactivity was found primarily in the neuropil and followed a generally increasing caudal-to-rostral gradient along the neuraxis. Densest staining occurred in layer I of the cortex, the CA1 field of the hippocampus, and in a continuum of subcortical structures that included the caudate-putamen, olfactory tubercle, nucleus accumbens, bed nucleus of the stria terminalis, amygdala, and medial preoptic area-hypothalamus. In the brain stem, staining was seen in the central gray and in ascending visceral relay nuclei, but was essentially absent in areas related to ascending somatosensory information (e.g., the cochlear nuclei or vestibular complex) and motor control (e.g., nucleus ruber or the motor nuclei of the cranial nerves). Staining in dorsal thalamus was likewise modest in most somatosensory and somatomotor relay nuclei, but dark in certain other structures (e.g., mediodorsal nucleus, lateral complex). This distributional pattern raises the question of whether synapses in all areas containing high levels of GAP-43/B-50 are capable of undergoing functional plasticity, or whether the protein may function in some of these areas in some other capacity (e.g., general signal transduction).
生长相关蛋白43（GAP - 43，即B - 50、F1、pp46）是一种神经元特异性磷蛋白，与突触关系的发育和调节有关。虽然大多数神经元在突触发生完成后停止高水平表达GAP - 43（雅各布森等人，1986年），但某些脑区在整个生命过程中仍持续含有大量该蛋白（奥斯特赖歇尔等人，1986年）；在至少一个这样的区域，该蛋白的磷酸化与突触增强的基础事件有关（洛温格等人，1985年）。在本研究中，我们使用间接免疫过氧化物酶法，用两种不同抗体绘制了8只成年大鼠脑中GAP - 43/B - 50的分布：一种是用绵羊制备的针对纯化蛋白的单特异性多克隆抗体，另一种是用兔子制备的亲和纯化IgG。特异性免疫反应主要见于神经毡，并沿神经轴从尾端到吻端呈大致递增的梯度。最密集的染色出现在皮质的I层、海马的CA1区，以及包括尾状核 - 壳核、嗅结节、伏隔核、终纹床核、杏仁核和内侧视前区 - 下丘脑在内的连续皮质下结构中。在脑干中，中央灰质和上升的内脏中继核中有染色，但在与上升的躯体感觉信息相关的区域（如耳蜗核或前庭复合体）和运动控制区域（如红核或颅神经运动核）基本没有染色。背侧丘脑的大多数躯体感觉和躯体运动中继核中的染色同样不明显，但在某些其他结构（如背内侧核、外侧复合体）中染色较深。这种分布模式提出了一个问题，即所有含有高水平GAP - 43/B - 50的区域中的突触是否都能够经历功能可塑性，或者该蛋白在其中一些区域是否可能以其他某种能力发挥作用（如一般信号转导）。
