Hypothalamic astroglial connexins are required for brain glucose sensing-induced insulin secretion.

Hypothalamic glucose detection participates in maintaining glycemic balance, food intake, and thermogenesis. Although hypothalamic neurons are the executive cells involved in these responses, there is increasing evidence that astrocytes participate in glucose sensing (GS); however, it is unknown whether astroglial networking is required for glucose sensitivity. Astroglial connexins 30 and 43 (Cx30 and Cx43) form hexameric channels, which are apposed in gap junctions, allowing for the intercellular transfer of small molecules such as glucose throughout the astroglial networks.

Expression profiling of prospero in the Drosophila larval chemosensory organ: Between growth and outgrowth.

Background: The antenno-maxilary complex (AMC) forms the chemosensory system of the Drosophila larva and is involved in gustatory and olfactory perception. We have previously shown that a mutant allele of the homeodomain transcription factor Prospero (prosVoila1, V1), presents several developmental defects including abnormal growth and altered taste responses. In addition, many neural tracts connecting the AMC to the central nervous system (CNS) were affected.

Spatio-temporal expression of Prospero is finely tuned to allow the correct development and function of the nervous system in Drosophila melanogaster.

Adaptive animal behaviors depend upon the precise development of the nervous system that underlies them. In Drosophila melanogaster, the pan-neural prospero gene (pros), is involved in various aspects of neurogenesis including cell cycle control, axonal outgrowth, neuronal and glial cell differentiation. As these results have been generally obtained with null pros mutants inducing embryonic lethality, the role of pros during later development remains poorly known.

Targeted calretinin expression in granule cells of calretinin-null mice restores normal cerebellar functions.

Ca2 binding proteins such as calretinin, characterized by the presence of EF-hand motifs that bind Ca2+ ions, are involved in the shaping of intraneuronal Ca2+ fluxes. In the cerebellar cortex, information processing tightly relies on variations in intracellular Ca2+ concentration in Purkinje and granule cells. Calretinin-deficient (Cr-/-) mice present motor discoordination, suggesting cellular and network cerebellar dysfunctions.

Expression of Ca(2+) Transport Genes in Platelets and Endothelial Cells in Hypertension.

-Altered Ca(2+) handling is observed in different cells in essential hypertension. We investigated the expression of sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA) and inositol 1,4,5-trisphosphate receptor (IP(3)R) isoforms in platelets and aortic endothelial cells (EC) isolated from spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats by ratio reverse-transcriptase-polymerase chain reaction (RT-PCR) analysis and Western blotting. SERCA2b and SERCA3 were assessed at mRNA (EC and platelets) and at protein level (platelets).