Search results for "Median Eminence"
showing 5 items of 5 documents
Young neurons from medial ganglionic eminence disperse in adult and embryonic brain.
1999
In this study, we identified neuronal precursors that can disperse through adult mammalian brain tissue. Transplanted neuronal precursors from embryonic medial ganglionic eminence (MGE), but not from lateral ganglionic eminence (LGE) or neocortex, dispersed and differentiated into neurons in multiple adult brain regions. In contrast, only LGE cells were able to migrate efficiently from the adult subventricular zone to the olfactory bulb. In embryonic brain slices, MGE cells migrated extensively toward cortex. Our results demonstrate that cells in different germinal regions have unique migratory potentials, and that adult mammalian brain can support widespread dispersion of specific populati…
Perineuronal Net Formation and the Critical Period for Neuronal Maturation in the Hypothalamic Arcuate Nucleus
2019
In leptin-deficient ob/ob mice, obesity and diabetes are associated with abnormal development of neurocircuits in the hypothalamic arcuate nucleus (ARC)1, a critical brain area for energy and glucose homoeostasis2,3. Because this developmental defect can be remedied by systemic leptin administration, but only if given before postnatal day 28, a critical period for leptin-dependent development of ARC neurocircuits has been proposed4. In other brain areas, critical-period closure coincides with the appearance of perineuronal nets (PNNs), extracellular matrix specializations that restrict the plasticity of neurons that they enmesh5. Here we report that in humans and rodents, subsets of neurons…
The LepR-mediated leptin transport across brain barriers controls food reward
2018
Objective Leptin is a key hormone in the control of appetite and body weight. Predominantly produced by white adipose tissue, it acts on the brain to inhibit homeostatic feeding and food reward. Leptin has free access to circumventricular organs, such as the median eminence, but entry into other brain centers is restricted by the blood–brain and blood–CSF barriers. So far, it is unknown for which of its central effects leptin has to penetrate brain barriers. In addition, the mechanisms mediating the transport across barriers are unclear although high expression in brain barriers suggests an important role of the leptin receptor (LepR). Methods We selectively deleted LepR in brain endothelia…
Morphological and electrophysiological evidence for habenular influence on the guinea-pig pineal gland
1981
The central innervation of the guinea-pig pineal gland was investigated by histological and electrophysiological methods: Staining the pineal gland and the epithalamus, a double route of central innervation could be shown in the anterior part of the organ: (a) Fibres from the habenular nuclei, mainly from the lateral part, penetrate the organ via the pineal stalk. (b) Other fibres join the striae medullares and running in the habenulae reach the organ more dorsally. The fibres end in the intercellular space where they form a dense network. In 15 male guinea-pigs under urethane anesthesia, two series of unit recording experiments were performed: (a) Recordings were made from 128 units in the…
MR IMAGING AND HORMONAL FINDINGS IN PATIENTS WITH IDIOPATHIC GROWTH HORMONU DEFICIENCY
1993
Until the introduction of MR imaging in neuroradiological diagnostic, diagnosis of the ecotopic posterior pituitary lobe, first described by the pathologist Priesel in 1920, was rare. Recently it has increasingly been diagnosed by MR in patients whose anamnesis showed birth trauma. We performed MR of the hypothalamic-pituitary region in 17 patients with idiopathic growth hormone deficiency. 8 patients had additional deficiencies of the anterior pituitary lobe whereas the function of the posterior lobe of the hypophysis was normal in all patients. Indications of birth trauma were present in only 2 patients. The cause of anterior lobe insufficiency was determined by MR in 8 patients with panh…