Robertson R T, Mostamand F, Kageyama G H, Gallardo K A, Yu J
Department of Anatomy, College of Medicine, University of California, Irvine 91717.
Brain Res Dev Brain Res. 1991 Jan 15;58(1):81-95. doi: 10.1016/0165-3806(91)90240-j.
A characteristic pattern of acetylcholinesterase (AChE) activity is expressed transiently in primary auditory cortex (cortical area 41) of developing laboratory rats during early postnatal life. This AChE activity occurs as a dense plexus in cortical layer IV and the deep part of layer III. This transient band of AChE activity is first detected by histochemical techniques on postnatal day (P) 3, reaches peak intensity at approximately P8-10, and declines to form the adult pattern by P23. The ventral nucleus of the medial geniculate body of the thalamus also displays prominent, and transient, staining for AChE. This intense staining for AChE, found within neuronal somata and neuropil, is detected at the time of birth, reaches peak intensity around P8, and declines to adult levels by P16. The areal and laminar patterns of the transient band of AChE activity in temporal cortex correspond to the patterns of anterograde transneuronal labeling of geniculocortical terminals following injection of wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP) into the inferior colliculus. Placement of lesions that include the medial geniculate nucleus or the geniculocortical axons results in a marked decrease in AChE staining in thalamorecipient layers of auditory cortex. Placement of lesions that include the medial globus pallidus reduce AChE staining of some axons in temporal cortex of developing rats, but the dense band of AChE in layers III and IV remains. Placement of lesions in the inferior colliculus in newborn animals results in marked decrease in AChE staining in cells of the ipsilateral ventral medial geniculate nucleus and in ipsilateral auditory cortex of developing pups. These data indicate that transiently expressed AChE activity is characteristic of geniculocortical neurons, including their somata in the medial geniculate body and their terminal axons in primary auditory cortex. This AChE activity is expressed early in postnatal development, probably during the time when thalamocortical axons are proliferating in cortical layer IV and forming synaptic contacts with cortical neurons.
在出生后的早期生活中，发育中的实验大鼠初级听觉皮层（第41区皮层）会短暂表达一种特征性的乙酰胆碱酯酶（AChE）活性模式。这种AChE活性以密集的神经丛形式出现在皮层IV层和III层深部。这种AChE活性的短暂条带最早在出生后第3天（P3）通过组织化学技术检测到，在大约P8 - 10时达到峰值强度，并在P23时下降形成成年模式。丘脑内侧膝状体腹侧核也显示出明显的、短暂的AChE染色。这种在神经元胞体和神经毡内发现的强烈AChE染色在出生时就被检测到，在P8左右达到峰值强度，并在P16时下降到成年水平。颞叶皮层中AChE活性短暂条带的区域和层状模式与将与辣根过氧化物酶结合的小麦胚芽凝集素（WGA - HRP）注入下丘后膝状体 - 皮层终末的顺行跨神经元标记模式相对应。包括内侧膝状体核或膝状体 - 皮层轴突的损伤会导致听觉皮层丘脑接受层中AChE染色显著减少。包括内侧苍白球的损伤会减少发育中大鼠颞叶皮层中一些轴突的AChE染色，但III层和IV层中AChE的密集条带仍然存在。新生动物下丘的损伤会导致发育中小鼠同侧腹内侧膝状体核细胞和同侧听觉皮层中AChE染色显著减少。这些数据表明，短暂表达的AChE活性是膝状体 - 皮层神经元的特征，包括它们在内侧膝状体中的胞体以及它们在初级听觉皮层中的终末轴突。这种AChE活性在出生后发育早期表达，可能是在丘脑 - 皮层轴突在皮层IV层增殖并与皮层神经元形成突触联系的时候。
