In addition to action potential-evoked exocytotic release at neurohypophysial nerve terminals, the neurohormones arginine vasopressin (aVP) and oxytocin (OT) undergo Ca(2+)-dependent somatodendritic release within the supraoptic and paraventricular hypothalamic nuclei. However, the cellular and molecular mechanisms that underlie this release have not been elucidated. In the present study, the whole-cell patch-clamp technique was utilized in combination with high-time-resolved measurements of membrane capacitance (C(m)) and microfluorometric measurements of cytosolic free Ca(2+) concentration ([Ca(2+)](i)) to examine the Ca(2+) and stimulus dependence of exocytosis in the somata of magnocellular neurosecretory cells (MNCs) isolated from rat supraoptic nucleus (SON).
View Article and Find Full Text PDFOrexin (hypocretin)-containing projections from lateral hypothalamus (LH) are thought to play an important role in the regulation of feeding behaviour and energy balance. In rodent studies, central administration of orexin peptides increases food intake, and orexin neurones in the LH are activated by hypoglycaemia during fasting. In addition, administration of orexins into the fourth ventricle or the dorsal motor nucleus of the vagus (DMV) has been shown to stimulate gastric acid secretion and motility, respectively, via vagal efferent pathways.
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