Morphological study on development of nerve growth factor-positive neurons in the cerebellum of human fetus / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the growth and development of nerve growth factor (NGF)-positive neurons in the cerebellum of midanaphase human fetus.</p><p><b>METHODS</b>The expression of the NGF-positive neurons in the cerebrum of human fetus was observed by immunohistochemical methods, and the integral absorbance (IA) was detected.</p><p><b>RESULTS</b>By the 3rd to 4th month of gestation, neurons was seen in the ependymal, central, and marginal plate of cerebellum; the nucleus was oval and the neurons had short and small processes. By the 5th to 7th month of gestation, the number of NGF-positive neurons increased, the expressions enhanced, the nucleus was round-, oval-, or fusiform-shaped, the neurons grew larger in size, and the Purkinje cells showed NGF-positive expression. By the 8th to 10th month of gestation, the NGF-positive expression was enhanced with deeper dying, the body of Purkinje cells grew larger gradually, and the number of NGF-positive neurons in the granular cell layer and molecular layer increased. IA of the cerebellar cortical neurons of the 3rd, 4th, 5th, 6th, 7th, and 8th month of gestation showed an increasing trend, and significant difference was observed (P < 0. 05).</p><p><b>CONCLUSION</b>NGF-positive neurons in the cerebellum play an important role for differentiation, proliferation, migration, and growth of neurons in the cerebellum.</p>

Morphology of nitric oxide synthase positive neurons in the cerebellar cortex of midanaphase human fetus / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the growth and development of nitric oxide synthase (NOS)-positive neurons in the cerebellum of human fetus in the midanaphase.</p><p><b>METHOD</b>The positive expression of the NOS-positive neurons in the cerebellum of midanaphase human fetus was observed by immunohistochemistry.</p><p><b>RESULTS</b>By the sixth to seventh month of gestation, NOS-positive neurons were seen in the ependymal layer of the cerebellum. The nucleus was oval-shaped and the neurons had short and small processes. By the eighth to ninth month, NOS-positive neurons were found in the central layer of the cerebellum and the nucleus was round-, oval-, or fusiform-shaped; meanwhile, the neurons grew larger in size with richer cytoplast and heavier staining. The beaded nerve fibers reached the marginal layer and the layer became thickened on the tenth month, which generally was composed of 5 to 6 layers of NOS-positive neurons that were tightly aligned. Some NOS-positive neurons were in smaller size with the cell body and the nerve fibers grew well.</p><p><b>CONCLUSION</b>Nitric oxide generated by NOS of the NOS-positive neurons in the cerebellum plays an important role in the differentiation, proliferation, and migration of neurons and gliacytes.</p>

Immunohistochemical study on development of nitric oxide synthase-positive neurons in the frontal lobe of cerebrum of midanaphase human fetus / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the development of nitric oxide synthase (NOS)-positive neurons in the frontal lobe of the cerebrum of human fetus in midanaphase.</p><p><b>METHODS</b>The positive expression of the NOS-positive neurons in the frontal lobe of cerebrum of human fetus was observed by immunohistochemistry.</p><p><b>RESULTS</b>By the 7th to 8th month of gestation, NOS-positive neurons in the cortical plate of frontal lobe demonstrated themselves inequality of sizes and morphological difference in the deeper layers with interspersed distribution and increased NOS response, and the distribution of beaded nerve fiber was observed between neurons of cerebral tissues. By the 9th to 10th month of gestation, NOS-positive neurons in the deeper layers of cortical plate of frontal lobe developed slightly in size of the cell body with richer cytoplast, full shape and deeper dyeing and extrusive beaded nerve fibers, and the NOS-positive neurons scattered in the shallow layer of cortical plate presented with round or oval shape. The nucleus developed bigger but with sparse cytoplasm and clear nerve process.</p><p><b>CONCLUSION</b>NOS-positive neurons in the deeper layer of cortical plate of lobus frontal consist of largely network of neural system and produce micro-environment with higher concentration of NO, which favors the differentiation, proliferation, migration, and development of various neurons.</p>