Immunocytochemical localization of reelin in the olfactory bulb of the heterozygous reeler mouse: an animal model for schizophrenia.

Because heterozygous reeler (HR) mice share some abnormal traits with schizophrenic patients, and schizophrenia is often accompanied by impairment of olfactory function, this study examines reelin in the olfactory bulb of the HR mouse. In the WT mouse, reelin immunoreactivity is found in the extracellular matrix, and in the cytoplasm of olfactory nerve fibers, GABAergic interneurons, and glutamatergic mitral cells. Western blot analysis reveals that reelin immunoreactivity in the HR mouse is reduced by 45% compared to WT mouse.

Proliferation of a subpopulation of reactive astrocytes following needle-insertion lesion in rat.

It is well known that traumatic injuries of the CNS induce a gliotic reaction, characterized by the presence of reactive astrocytes. Reactive astrocytes exhibit enhanced expression of the astrocyte-specific intermediate filament, glial fibrillary acidic protein (GFAP), hypertrophy, and thickened processes. Recently, we have demonstrated that injuries of the CNS induce a re-expression of an embryonic intermediate filament-associated protein, IFAP-70/280 kDa.

Reelin in the extracellular matrix and dendritic spines of the cortex and hippocampus: a comparison between wild type and heterozygous reeler mice by immunoelectron microscopy.

Reelin is a glycoprotein ( approximately 400 kDa) secreted by GABAergic neurons into the extracellular matrix of the neocortex and hippocampus as well as other areas of adult rodent and nonhuman primate brains. Recent findings indicate that the heterozygote reeler mouse (haploinsufficient for the reeler gene) shares several neurochemical and behavioral abnormalities with schizophrenia and bipolar disorder with mania. These include (1) a downregulation of both reelin mRNA and the translated proteins, (2) a decrease in the number of dendritic spines in cortical and hippocampal neurons, (3) a concomitant increase in the packing density of cortical pyramidal neurons, and (4) an age-dependent decrease in prepulse inhibition of startle.

Reelin function in neural stem cell biology.

In the adult brain, neural stem cells (NSC) must migrate to express their neuroplastic potential. The addition of recombinant reelin to human NSC (HNSC) cultures facilitates neuronal retraction in the neurospheroid. Because we detected reelin, alpha3-integrin receptor subunits, and disabled-1 immunoreactivity in HNSC cultures, it is possible that integrin-mediated reelin signal transduction is operative in these cultures.

Colocalization of integrin receptors and reelin in dendritic spine postsynaptic densities of adult nonhuman primate cortex.

The expression of telencephalic reelin (Reln) and glutamic acid decarboxylase mRNAs and their respective cognate proteins is down-regulated in postmortem brains of schizophrenia and bipolar disorder patients. To interpret the pathophysiological significance of this finding, immunoelectron microscopic experiments are required, but these cannot be carried out in postmortem human brains. As an alternative, we carried out such experiments in the cortex of rats and nonhuman primates.