Robertson R T, Hanes M A, Yu J
Department of Anatomy and Neurobiology, College of Medicine, University of California, Irvine 92717.
Brain Res. 1988 Jun 1;469(1-2):1-23. doi: 10.1016/0165-3806(88)90165-4.
Transient acetylcholinesterase (AChE) activity is characteristic of cortical area 17 of the developing laboratory rat during the second and third postnatal weeks of life. This AChE activity is most intense in a band that corresponds to cortical layer IV and the deep part of layer III, but also is found in the outer half of cortical layer I and in layer VI. The morphology of the pattern of the histochemical reaction product indicates that the transient AChE is characteristic of an axonal terminal field. The present report describes results of 3 sets of experiments aimed at determining the source of transient AChE in cortical area 17. First, placement of lesions in portions of the basal forebrain or in the cingulate bundle results in a decrease in the general pattern of AChE throughout occipital cortex and especially in layer I, but the transient bands of AChE in layers III-IV of cortical area 17 are not eliminated. Second, kainic acid or cobalt chloride injections in cortical area 17 result in the loss of many AChE-positive neuronal somata but do not eliminate the transient pattern of AChE in thalamo-recipient layers of cortical area 17. Similarly, treatment of fetuses with mitotic inhibitors that eliminate many of the neurons destined for granular and supragranular layers does not eliminate transient patterns of AChE. Third, lesions that include the lateral geniculate nucleus of the thalamus or geniculocortical projections result in a marked loss of the pattern of AChE in thalamo-recipient layers of cortical area 17, without significant loss in other layers of area 17 or in other regions of occipital cortex. These data support the hypothesis that the transient AChE found in thalamo-recipient layers of cortical area 17 is contained within geniculocortical axon terminals.
在出生后第二和第三周的发育过程中，瞬态乙酰胆碱酯酶（AChE）活性是实验大鼠17区皮质的一个特征。这种AChE活性在对应于皮质第IV层和第III层深部的条带中最为强烈，但在皮质第I层的外半层和第VI层中也有发现。组织化学反应产物模式的形态表明，瞬态AChE是轴突终末场的一个特征。本报告描述了3组实验的结果，旨在确定17区皮质瞬态AChE的来源。首先，在基底前脑部分或扣带束中造成损伤，会导致整个枕叶皮质尤其是第I层的AChE总体模式减少，但17区皮质第III - IV层中的瞬态AChE条带并未消除。其次，在17区皮质注射红藻氨酸或氯化钴会导致许多AChE阳性神经元胞体丢失，但不会消除17区皮质丘脑接受层中的瞬态AChE模式。同样，用有丝分裂抑制剂处理胎儿，消除许多注定要进入颗粒层和颗粒上层的神经元，也不会消除瞬态AChE模式。第三，包括丘脑外侧膝状体核或膝状体 - 皮质投射的损伤，会导致17区皮质丘脑接受层中AChE模式明显丧失，而17区的其他层或枕叶皮质的其他区域没有明显损失。这些数据支持这样的假设，即在17区皮质丘脑接受层中发现的瞬态AChE包含在膝状体 - 皮质轴突终末内。
