Switch-like PKA responses in the nucleus of striatal neurons.

Although it is known that protein kinase A (PKA) in the nucleus regulates gene expression, the specificities of nuclear PKA signaling remain poorly understood. Here, we combined computational modeling and live-cell imaging of PKA-dependent phosphorylation in mouse brain slices to investigate how transient dopamine signals are translated into nuclear PKA activity in cortical pyramidal neurons and striatal medium spiny neurons. We observed that the nuclear PKA signal in striatal neurons featured an ultrasensitive responsiveness, associated with fast all-or-none responses, which is not consistent with the commonly accepted theory of a slow and passive diffusion of catalytic PKA in the nucleus.

[Physiopathology of cAMP/PKA signaling in neurons].

Cyclic adenosine monophosphate (cAMP) and the cyclic-AMP dependent protein kinase (PKA) regulate a plethora of cellular functions in virtually all eukaryotic cells. In neurons, the cAMP/PKA signaling cascade controls a number of biological properties such as axonal growth, synaptic transmission, regulation of excitability or long term changes in the nucleus. Genetically-encoded optical biosensors for cAMP or PKA considerably improved our understanding of these processes by providing a real-time measurement in living neurons.

Oatp1a4 and an L-thyroxine-sensitive transporter mediate the mouse blood-brain barrier transport of amyloid-β peptide.

The influx of amyloid-β peptide (Aβ) across the blood-brain barrier is partly mediated by the receptor for advanced glycation end products (RAGE). But other transporters, like Oatp (organic anion transporter polypeptide, SLC21) transporters, could also be involved. We used in situ brain perfusion to show that rosuvastatin and taurocholate, two established Oatp1a4 substrates, decreased (5-fold) the Clup of [3H]Aβ while L-thyroxine increased it (5.

[Epidemiological profile of the schistosomiasis in school children in the Agneby Region (south-east of Côte-d'Ivoire)].

A parasitological survey was conducted in the Agnéby region (south-east Côte-d'Ivoire) from November 2000 to February 2001 in order to establish the epidemiological profile of schistosomiasis in school children in this region. Stools and urines of 724 school children were examined. Faeces were examined by direct analysis completed by Kato and Ritchie methods.