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Medial Hypothalamus (medial + hypothalamus)
Selected AbstractsImmunolesion of Hindbrain Catecholaminergic Projections to the Medial Hypothalamus Attenuates Penile Reflexive Erections and Alters Hypothalamic Peptide mRNAJOURNAL OF NEUROENDOCRINOLOGY, Issue 5 2002G. S. Fraley Abstract The central mechanisms underlying diabetes-associated impotence are currently unknown. This study utilized immunolesion techniques to eliminate hindbrain catecholaminergic projections to the medial hypothalamus which have been reported to be glucoresponsive. The immunolesioned male rats had an attenuated feeding response to glucoprivic challenge. Furthermore, these lesioned rats had significantly attenuated penile reflexes. Northern blot analyses of hypothalamic oxytocin mRNA expression showed a significant increase; however, neuropeptide Y mRNA expression did not. These results suggest that hindbrain catecholaminergic neurones may alter the expression of hypothalamic neuropeptides that stimulate penile erections based upon glucoregulatory signals from the periphery. [source] Different Electroclinical Manifestations of the Epilepsy Associated with Hamartomas Connecting to the Middle or Posterior HypothalamusEPILEPSIA, Issue 9 2003Alberto J. R. Leal Summary:,Purpose: The epilepsy associated with hypothalamic hamartomas (HHs) has typical clinical, electrophysiologic, and behavioral manifestations refractory to drug therapy and with unfavorable evolution. It is well known that only sessile lesions produce epilepsy, but no correlation has been established between the different types of sessile hamartomas and the diverse manifestations of the epilepsy. We correlate anatomic details of the hamartoma and the clinical and neurophysiologic manifestations of the associated epilepsy. Methods: HHs of seven patients with epilepsy (ages 2, 25 years) were classified as to lateralization and connection to the anteroposterior axis of the hypothalamus by using high-resolution brain magnetic resonance imaging. We correlated the anatomic classification with the clinical and neurophysiologic manifestations of the epilepsy as evaluated in long-term (24 h) video-EEG recordings. Results: HHs ranged in size from 0.4 to 2.6 cc, with complete lateralization in six of seven patients. Ictal manifestations showed good correlation with the lobar involvement of ictal/interictal EEGs. These manifestations suggest the existence of two types of cortical involvement, one associated with the temporal lobe, produced by hamartomas connected to the posterior hypothalamus (mamillary bodies), and the other associated with the frontal lobe, seen in lesions connecting to the middle hypothalamus. Conclusions: A consistent clinical and neurophysiologic pattern of either temporal or frontal lobe cortical secondary involvement was found in the patients of our series. It depends on whether the hamartoma connects to the mamillary bodies (temporal lobe cases) or whether it connects to the medial hypothalamus (frontal lobe cases). [source] Genetic mapping of Foxb1-cell lineage shows migration from caudal diencephalon to telencephalon and lateral hypothalamusEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 10 2008Tianyu Zhao Abstract The hypothalamus is a brain region with vital functions, and alterations in its development can cause human disease. However, we still do not have a complete description of how this complex structure is put together during embryonic and early postnatal stages. Radially oriented, outside-in migration of cells is prevalent in the developing hypothalamus. In spite of this, cell contingents from outside the hypothalamus as well as tangential hypothalamic migrations also have an important role. Here we study migrations in the hypothalamic primordium by genetically labeling the Foxb1 diencephalic lineage. Foxb1 is a transcription factor gene expressed in the neuroepithelium of the developing neural tube with a rostral expression boundary between caudal and rostral diencephalon, and therefore appropriate for marking migrations from caudal levels into the hypothalamus. We have found a large, longitudinally oriented migration stream apparently originating in the thalamic region and following an axonal bundle to end in the anterior portion of the lateral hypothalamic area. Additionally, we have mapped a specific expansion of the neuroepithelium into the rostral diencephalon. The expanded neuroepithelium generates abundant neurons for the medial hypothalamus at the tuberal level. Finally, we have uncovered novel diencephalon-to-telencephalon migrations into septum, piriform cortex and amygdala. [source] Immunolesion of Hindbrain Catecholaminergic Projections to the Medial Hypothalamus Attenuates Penile Reflexive Erections and Alters Hypothalamic Peptide mRNAJOURNAL OF NEUROENDOCRINOLOGY, Issue 5 2002G. S. Fraley Abstract The central mechanisms underlying diabetes-associated impotence are currently unknown. This study utilized immunolesion techniques to eliminate hindbrain catecholaminergic projections to the medial hypothalamus which have been reported to be glucoresponsive. The immunolesioned male rats had an attenuated feeding response to glucoprivic challenge. Furthermore, these lesioned rats had significantly attenuated penile reflexes. Northern blot analyses of hypothalamic oxytocin mRNA expression showed a significant increase; however, neuropeptide Y mRNA expression did not. These results suggest that hindbrain catecholaminergic neurones may alter the expression of hypothalamic neuropeptides that stimulate penile erections based upon glucoregulatory signals from the periphery. [source] | ||||||||||