Colocalization And Expression Of ErbB4 And PV In The Cerebral Cortex And Hippocampus Of Wild Type And Reeler Mice

Reelin is an extracellular matrix protein, which is mainly synthesized and secreted by Cajal-Retzius cells(CR cells), and is short-lived in the cerebral cortex. Reelin gene deficient mice, was named reeler mice. Studies have showed that Reelin is associated with many neurological diseases. ErbB4 is one of the neuregulin( NRG) receptor proteins, belonging to the receptor tyrosine protein kinase family, and is expressed in GABA interneurons, and closely with the development of neurological disorders such as schizophrenia. Parvalbumin(PV) is a kind of calcium binding protein with small molecular weight, which is a marker of GABA interneurons, and the axonal endings of PV-positive cells can form the inhibitory synapses with the axons of pyramidal cells in the beginning section, or cell body. And the abnormal activity of interneuron is closely related to the neurological diseases.In order to comparative study on the expression and co-localization of ErbB4 and PV in cerebral cortex and hippocampus of the adult wild type mice and reeler mice, immunofluorescence histochemistry for ErbB4 and PV was performed and the structured illumination microscope was used for observation, photograph and quantitative analysis, and the western blot was used to compare the expression level of ErbB4 and PV in cerebral cortex and hippocampus among three genotypes of mouse. The results are as follows:1. Immunofluorescence staining showed that ErbB4 and PV positive cells were distributed in the cerebral cortex and hippocampus of the adult wild type mice, heterozygous reeler mice and homozygous reeler mice. The ErbB4 and PV were mainly expressed in the intermediate cortical plate(ICP) and deeper cortical plate(DCP) of the wild type mice and heterozygous reeler mice, whereas ErbB4 and PV positive cells were mainly located in the upper cortical plate(UCP) and DCP of the homozygous reeler mice. And the proportion of ErbB4 and PV positive cells in the UCP of homozygous reeler mice were increased significantly, whereas the proportion of ErbB4 and PV positive cells in DCP of homozygous reeler mice were decreased significantly. The ErbB4 and PV positive cells were mainly located in the pyramidal cells layer of CA1 region and CA3 region and in granular cell layer and subgranular cell layer of DG region in the three genotypes mice.2. Statistical analysis showed that the expression level of ErbB4 in the cerebral cortex of heterozygous reeler mice and homozygous reeler mice is below the normal wild-type mice, but there was no significant difference. And the expression level of Erb B4 in the hippocampus of homozygous reeler mice and heterozygous reeler mice were higher than that in wild type mice, and only homozygous reeler mice showed significant difference. And the expression level of PV in cerebral cortex and hippocampus of the heterozygous reeler mice and homozygous reeler mice were lower than that in normal wild-type mice, and only the expression level in hippocampus showed significant difference.3. Double immunofluorescence histochemical staining showed that the co-localization of ErbB4 and PV in cerebral cortex and hippocampus of wild type mice, heterozygous reeler mice and homozygous reeler mice was normal, and the ErbB4/PV positive cell were co-located in cell membrane.In summary, ErbB4 and PV express and co-locate in cerebral cortex and hippocampus of adult wild type, heterozygous reeler mice and homozygous reeler mice. And the expression level of ErbB4 and PV in cerebral cortex and different parts of hippocampus of the three different genotypes mice was different, these results suggested that Reelin affect the expression of ErbB4 and PV in cerebral cortex and hippocampus, and its effects on the expression ErbB4 and PV showed tissue specificity, but it did not affect the co-localization of ErbB4 and PV in the cerebral cortex and hippocampus.