Developmental expression of monocyte chemoattractant protein-1 in the human cerebellum and brainstem

The developmental expression of monocyte chemoattractant protein-1 (MCP-1) in the cerebellum, medulla oblongata and pons was investigated in 26 normal human brains, ranging from 20 weeks of gestation (GW) to adulthood by means of an immunohistochemical method. Immunoreactivity to MCP-1 was observed in neurons of the cerebellum and brainstem, and was mainly distributed in the cytoplasm and dendrites. MCP-1-positive Purkinje cells appeared at 27 GW, reached a peak at 36 GW, and then decreased after 1 month of age, almost completely disappearing by 1-2 years of age. MCP-1-reactive neurons in the dentate nucleus and inferior olivary nucleus showed temporal increases similar to that of Purkinje cells. In the pons, however, MCP-1 reactivity was low in neurons of the pontine nuclei persisting from the fetal to the adult period, and was very low and short in the reticular formation and cranial nerve nuclei during the fetal and/or neonatal period. MCP-1 Western blotting of the cerebellar cortex confirmed the specificity of the immunohistochemistry. Our results suggest that MCP-1 may be related to the maturation of Purkinje cells, the dentate nucleus, the inferior olivary nucleus, and their network, promoting the growth of dendrites and synapses. Furthermore, MCP-1 may also be useful for the study of abnormal neuron development and ischemic damage.