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Updated: Jun 10, 2026

Functional Interrogation of Adult Hypothalamic Neurogenesis with Focal Radiological Inhibition
Published on: November 14, 2013
Mitotic figures in the median eminence of the hypothalamus
Seymour Levine1, Arthur Saltzman, Stephen D Ginsberg
1Center for Dementia Research, Nathan Kline Institute, NYU Langone Medical Center, Orangeburg, NY 10962, USA.
Abstract:
The median eminence of the hypothalamus is part of the avenue by which neurosecreted hormones from the hypothalamic nuclei reach the pars nervosa (neural lobe) of the pituitary and eventually the bloodstream. Lithium treatment and osmotic stress increases the transport of neurosecretory hormones to the pituitary in the adult rat. Specialized astrocytes termed pituicytes in the pars nervosa of the pituitary participate in the secretory process and also develop considerable mitotic activity. The present work reveals similar mitotic figures in cells within the median eminence following 3 days of lithium treatment. The location and appearance of these mitoses add to the evidence that pituicytes are present in the median eminence. Moreover, mitoses occur within the ependymal (tanycyte) layer of the median eminence. Thus, the present results suggest that the tanycyte layer may contain pituicytes, indicating that the hypothalamus possesses specialized cells for modulating neurosecretion in response to osmotic challenges.
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