What is relationship between the medial preoptic area, the organum vasculosum of the lamina terminalis and Kallmann syndrome?

The medial preoptic area is a structure located in the hypothalamic anteroventral third ventricle region, and is closely related to the olfactory brain development and sexual differentiation of the brain. The medial preoptic area surrounds the organum vasculosum of the lamina terminalis, and both structures are the main areas where synthesis of gonadotropin-releasing hormone occurs in the brain. Neurons synthesizing gonadotropin-releasing hormone migrate from the medial nasal epithelium to the rostral brain and reach the organum vasculosum of the lamina terminalis and the medial preoptic area. Kallmann syndrome is a genetic disorder which combines hypogonadotropic hypogonadism and anosmia. Hypogonadism is characterized by the absence or reduced levels of gonadotropin-releasing hormone and anosmia due to olfactory bulb aplasia. This paper speculates on the connection between the development of the medial preoptic area, the organum vasculosum of the lamina terminalis and olfactory bulbs with Kallmann syndrome, since the anteroventral third ventricle region is crucial for the normal development of these structures and its connection with the olfactory nerves and sexual maturation.

Immunohistochemical study of Pax6 and Reissner fibre expression in the prenatal development of the mouse subcommissural organ

The subcommissural organ (SCO) releases glycoproteins into the ventricular cerebrospinal fluid (CSF), where they form Reissner's fibre (RF) and also secretes a CSF-soluble material different from RF-material. Pax6 is a transcription factor important for the regulation of cell proliferation, migration and differentiation in the developing brain. In the present work, we studied wild-type, heterozygous and homozygous Sey mice to compare the expression of RF-antibody and Pax6 in the SCO and adjacent structures. In wild-type mice between E15 to E18, we observed Pax6 expression in cells surrounding the secretory cells of the SCO, and RF-immunoreactive material only in the SCO ependymal cell layer and its basal process. In the heterozygous mice, the neuroanatomical structure of the SCO was present, but RF-antibody staining and Pax6 expression was scarce or almost undetectable; in the homozygous mice neither SCO nor other epithalamic structures were found. We suggest that Pax6 expression at the periphery of the SCO is essential for the development and activity of the organ (AU)

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