The Mechanism for Formation and Maintenance of Synapses in the Prefrontal Cortex by Biogenic Amines

5-HT2a受体在发育和成熟的大脑中介导5-羟色胺形成和维持突触的功能。我们提出了针对5-HT2A受体蛋白的特异性抗体。利用5-HT2A型受体抗体，观察了5-HT2A型受体在大鼠大脑皮质的分布规律。5-HT2a受体免疫反应广泛分布于大脑皮层。大脑皮层几乎所有神经元都有免疫反应，尤其是胞体轮廓和顶树突有较强的免疫反应。经抗GFAP鉴定的星形胶质细胞与5-HT2A型受体呈强阳性反应。尽管在常规的形态和功能研究中，5-HT2A受体在小脑中的存在存在差异，但我们的免疫组织化学研究表明，浦肯野细胞中有强烈的免疫反应。利用免疫电子显微镜技术，5-HT2a受体位于非对称性突触的突触后膜厚度的正下方，可能是谷氨酸能突触。为阐明5-羟色胺对谷氨酸受体的调节机制，本实验观察了6周龄大鼠大脑皮质5-羟色胺缺乏1周后谷氨酸受体结合的变化。AMPA受体，特别是GluR2表达上调。5-羟色胺似乎通过两种方式调节突触可塑性：通过改变羽毛羽毛受体亚型的组成来调节突触数目和钙通透性。

5-HT2A receptor has been shown to mediate the function of 5-HT for formation and maintenance of synapses in the developing and mature brain. We raised specific antibodies against receptor protein of 5-HT2A receptor. By using the antibodies distribution pattern of 5-HT2A receptor was examined in the cerebral cortex of the rat. Immunoreaction of 5-HT2A receptor was located diffusely in the cerebral cortex. Virtually all the neurons in the cerebral cortex had the immunoreactivity, and specially somal profiles and apical dendrites had strong immunoreaction. Astrocyte identified by using an antibody GF AP showed a strong immunoreaction of 5-HT2A receptors. Although discrepancies in terms of exsistence of 5-HT2A receptors in the cerebellum between conventional morphological and functional studies, our immunohistochemical study has shown a strong immunoreaction in the Purkinje cells. By using an immuno- electron microscopical technique 5-HT2A receptor was located just beneath the postsynaptic membrane thicknings of asymmetrical synapses, possibly glutamatergic ones. To clarify regulatory mechanism for glutamatergic receptors by 5-HT changes in receptor bindings of glutamate were examined in the cerebral cortex 6 week-old rat after 5-HT depletion for a week. AMPA receptor, specially GluR2 was upregulated. 5-HT appears to regulate synaptic plasticity into two way : regulating the number of synapses and Ca permeability by changing composition of Quill receptor suntypes.