Leptin is a critical neurotrophic factor for the development of neuronal pathways and synaptogenesis in the hypothalamus. Leptin receptors are also found in other brain regions, including the hippocampus, and a postnatal surge in leptin correlates with a time of rapid growth of dendritic spines and synapses in the hippocampus. Leptin is critical for normal hippocampal dendritic spine formation ...

Hypoxic pulmonary vasoconstriction (HPV) is an important homeostatic mechanism in which increases of [Ca2+]i are primary events. In this study, primary cultured, human pulmonary artery smooth muscle cells (hPASMC) were used to examine the role of TRPC channels in mediating [Ca2+]i elevations during hypoxia. Hypoxia (PO2) about 20 mm Hg) evoked a transient [Ca2+]i elevation that was reduced by r...

BACKGROUND Ca(2+) is essential for vesicle fusion with the plasma membrane in virtually all types of regulated exocytoses. However, in contrast to the well-known effects of a high cytoplasmic Ca(2+) concentration ([Ca(2+)](c)) in the prefusion phase, the occurrence and significance of Ca(2+) signals in the postfusion phase have not been described before. METHODOLOGY/PRINCIPAL FINDINGS We stud...

Intracellular Ca(2+) signals have been associated with cell polarization and locomotion. As cell motility underlies metastasis, we have sought to better characterize the Ca(2+) signaling events in HT1080 fibrosarcoma cells. We have tested the hypothesis that low voltage-activated (LVA) and nonvoltage-gated (NVG) channels of HT1080 cells participate in dynamic Ca(2+)-signaling events leading to ...

In the main olfactory bulb, activation of group I metabotropic glutamate receptors (mGluRs) by olfactory nerve stimulation generates slow (2 Hz) oscillations near the basal respiratory frequency. These oscillations arise in the glomerular layer and may be generated, in part, by the intrinsic neurons, the juxtaglomerular neurons. We investigated the physiological effects of group I mGluR agonist...

Orexin A and B are neuropeptides implicated in the regulation of sleep/wakefulness and energy homeostasis. The regulatory mechanism of the activity of orexin neurons is not precisely understood. Using transgenic mice in which orexin neurons specifically express yellow cameleon 2.1, we screened for factors that affect the activity of orexin neurons (a total of 21 peptides and six other factors w...

Synaptic transmission at central synapses has usually short latency and graded amplitude, thereby regulating threshold crossing and the probability of action potential generation. In the granular layer of the vestibulo-cerebellum, unipolar brush cells (UBCs) receive a giant synapse generating a stereotyped excitatory postsynaptic potential (EPSP)-burst complex with early-onset (∼2 ms) and high ...

Ca(+) signaling plays a crucial role in control of cell cycle progression, but the understanding of the dynamics of Ca(2+) influx and release of Ca(2+) from intracellular stores during the cell cycle is far from complete. The aim of the present study was to investigate the role of the free extracellular Ca(2+) concentration ([Ca(2+)](o)) in cell proliferation, the pattern of changes in the free...

The effect of 3-¿1-(p-chlorobenzyl)-5-(isopropyl)-3-tert-butylthioindol-2-yl-2, 2-dimethylpropanoic acid (MK-886), a leukotriene biosynthesis inhibitor, on Ca(2+) mobilization in Madin- Darby canine kidney cells has been examined by fluorimetry using fura-2 as a Ca(2+) indicator. MK-886 at 0.5 to 25 microM concentration dependently increased ¿Ca(2+)(i). The ¿Ca(2+)(i) increase comprised an imme...

The injury phase after myocardial infarcts occurs during reperfusion and is a consequence of calcium release from internal stores combined with calcium entry, leading to cell death by apoptopic and necrotic processes. The mechanism(s) by which calcium enters cells has(ve) not been identified. Here, we identify canonical transient receptor potential channels (TRPC) 3 and 6 as the cation channels...