Arai Y, Mizuguchi M, Takashima S
Department of Mental Retardation and Birth Defect Research, National Institute of Neuroscience, Tokyo, Japan.
Pediatr Neurol. 1996 Oct;15(3):203-6. doi: 10.1016/s0887-8994(96)00167-1.
We studied the immunohistochemical localization of the glutamate receptor subunits GluR1, GluR2/3, and GluR4 in brains of Down syndrome patients and of normal controls. In cerebral cortex of both the control and Down syndrome patients, weak GluR1 immunoreactivity was observed in the cytoplasm of neurons, especially pyramidal neurons, after 34 weeks of gestation. In Down syndrome patients, the staining of the neurons became more distinct after 21 years of age. After 32 years of age in Down syndrome patients, GluR1 immunoreactivity was also observed in the senile plaques, including the diffuse, primitive, and classic plaques. The immunoreactivity was observed in a cluster of several small swollen neurites in the senile plaques. GluR2/3 and GluR4 immunoreactivity was also observed in the cytoplasm of neurons, especially pyramidal neurons, after 34 weeks of gestation in controls and Down syndrome patients, but not in senile plaques. GluR4 immunoreactivity was also observed in the cell processes of astrocytes in both the normal and the Down syndrome brains. Excessive immunoreactivity of GluR1 may be involved in degeneration of neurons and the early formation of senile plaques in Down syndrome.
我们研究了唐氏综合征患者和正常对照者大脑中谷氨酸受体亚基GluR1、GluR2/3和GluR4的免疫组织化学定位。在对照者和唐氏综合征患者的大脑皮质中，妊娠34周后，在神经元尤其是锥体神经元的细胞质中观察到微弱的GluR1免疫反应性。在唐氏综合征患者中，21岁后神经元的染色变得更加明显。在唐氏综合征患者32岁后，在老年斑（包括弥漫性、原始性和典型性斑块）中也观察到了GluR1免疫反应性。在老年斑中几个小的肿胀神经突的簇中观察到了免疫反应性。在对照者和唐氏综合征患者妊娠34周后，在神经元尤其是锥体神经元的细胞质中也观察到了GluR2/3和GluR4免疫反应性，但在老年斑中未观察到。在正常和唐氏综合征大脑的星形胶质细胞的细胞突起中也观察到了GluR4免疫反应性。GluR1的过度免疫反应性可能与唐氏综合征中神经元的退化和老年斑的早期形成有关。
