We have studied the effect of the purified toxin from the funnel-web spider venom (FTX) and its synthetic analog (sFTX) on transmitter release and presynaptic currents at the mouse neuromuscular junction. FTX specifically blocks the a-conotoxin-and dihydropyridine-insensitive P-type voltage-dependent Ca2+ channd (VDCC) in cerebellar Purkinje cells. Mammalian neuromuscular transmission, which is insensitive to N-or L-type Ca2+ channel blockers, was effectively abolished by FTX and sFTX. These substances blocked the muscle contraction and the neurotransmitter release evoked by nerve stimulation. Moreover, presynaptic Ca2+ currents recorded extracellularly from the interior of the perineural sheaths of nerves innervating the mouse levator auris muscle were specifically blocked by both natural toxin and synthetic analogue. In a parallel set of experiments, K+-induced Ca'5 uptake by brain synaptosomes was also shown to be blocked or greatly diminished by FIX and sFVX. These results indicate that the predominant VDCC in the motor nerve terminals, and possibly in a significant percentage of brain synapses, is the P-type channel.Ca2' influx through voltage-dependent Ca2' channels (VDCCs) is the trigger for the release of neurotransmitters from the nerve terminals (1, 2). Three major types ofVDCC named T, L, and N were described in neuronal cells (3). The high-threshold L and N VDCCs are sensitive to the blocking effect of o-conotoxin (c-CgTX), and only the L type is affected by Ca2`channel antagonists of the 1,4-dihydropyridine (DHP) class. An intermediate-threshold VDCC channel called the P channel was identified in the; Purkinje cells of mammalian cerebellum and found to be insensitive to DHP and w-CgTX, but very sensitive to a low molecular weight fraction of the venom of the funnel-web spider Agelenopsis aperta (4). This funnel-web spider toxin (FTX) was also effective in blocking Ca2+ conductance and synaptic transmission at the squid giant synapse (4). Evoked release of neurotransmitter was shown to be dependent on Ca2+ influx through the N-type VDCC in sympathetic neurons by the inhibitory effect of w-CgTX and the lack of effect of DHP (5). By contrast, substance P release from dorsal root ganglia neurons (6, 7) and catecholamine release from chromaffin cells (8) are strongly inhibited by DHP, consistent with a major participation of L-type channels. However, mammalian motor nerve terminals are normally insensitive to either w-CgTX or DHP (9-11). Furthermore, in brain synaptosomes, K+-evoked Ca2' uptake and transmitter release are only partially sensitive to c-CgTX and DHP (12, 13). Thus the identity of the VDCC involved in transmitter release in the majority of the synapses at the mammalian central and peripheral nervous system has not been defined. The experiments presented here were designed to study the effect of FTX on transmitter release and Ca2+ influx at the mammalian neuromuscular junction and on Ca2+ uptake by cerebral cortex synaptosomes in order to determine whether a particular type of VDCC ...

Conversion to dementia is significantly higher in patients with neuropsychiatric symptoms. The MBI concept generates a new milestone in the refining of diagnosis of neurodegenerative diseases and the possibility of creating neuropsychiatric profiles. Its earlier identification will allow new possibilities for therapeutic intervention.

25Aim/hypothesis: Placenta of women with gestational diabetes mellitus (GDM) exhibits an 26 altered lipid metabolism. The mechanism by which GDM is linked to alterations in placental lipid 27 metabolism remains obscure. We hypothesized that high-glucose levels reduce mitochondrial fatty 28 acid oxidation (FAO) and increase triglyceride accumulation in human placenta. 29 Methods:To test this hypothesis, we measured FAO, fatty acid esterification, de novo fatty 30 acid synthesis, triglyceride levels and carnitine palmitoyltransferase activities (CPT) in placental 31 explants of women with GDM or with no pregnancy complication. 32 Results:In women with GDM, FAO was reduced by ~30% without change in mitochondrial 33 content, and triglyceride content was 3-fold higher than control group. Likewise, in placental 34

Development is often described as temporal sequences of developmental stages (DSs). When tables of DS are defined exclusively in the time domain they cannot discriminate histogenetic differences between different positions along a spatial reference axis. We introduce a table of DSs for the developing chick optic tectum (OT) based on time- and space-dependent changes in quantitative morphometric parameters, qualitative histogenetic features and immunocytochemical pattern of several developmentally active molecules (Notch1, Hes5, NeuroD1, β-III-Tubulin, synaptotagmin-I and neurofilament-M). Seven DSs and four transitional stages were defined from ED2 to ED12, when the basic OT cortical organization is established, along a spatial developmental gradient axis extending between a zone of maximal and a zone of minimal development. The table of DSs reveals that DSs do not only progress as a function of time but also display a spatially organized propagation along the developmental gradient axis. The complex and dynamic character of the OT development is documented by the fact that several DSs are simultaneously present at any ED or any embryonic stage. The table of DSs allows interpreting how developmental cell behaviors are temporally and spatially organized and explains how different DSs appear as a function of both time and space. The table of DSs provides a reference system to characterize the OT corticogenesis and to reliably compare observations made in different specimens.

Cognitive reserve is the ability to optimize performance through differential recruitment of brain networks, which may reflect the use of alternative cognitive strategies.ObjectivesTo identify factors related to cognitive reserve associated with progression from mild cognitive impairment (MCI) to degenerative dementia.MethodsA cohort of 239 subjects with MCI (age: 72.2±8.1 years, 58% women, education: 12 years) was assessed and followed for five years (2001 to 2006).ResultsIn the first year, 13.7% of MCI converted to dementia and 34.7% converted within three years (78.3% converted to Alzheimer’s dementia). Risk factors for those who converted were education less than 12 years, MMSE score less than 27, Boston naming test score less than 51, IQ (Intelligence Quotient) less than 111, age over 75 years, lack of occupation at retirement, and presence of intrusions in memory recall (all account for 56% of the variability of conversion).ConclusionsMCI patients are a population at high risk for dementia. The study of risk factors (e.g. IQ, education and occupation), particularly those related to cognitive reserve, can contribute important evidence to guide the decision-making process in routine clinical activity and public health policy.

Background: In the development of the central nervous system (CNS), neuronal migration and neuritogenesis are crucial processes for establishing functional neural circuits. This relies on the regulation exerted by several signaling molecules, which play important roles in axonal growth and guidance. The urokinase-type plasminogen activator (uPA)-in association with its receptor-triggers extracellular matrix proteolysis and other cellular processes through the activation of intracellular signaling pathways. Even though the uPA-uPAR complex is well characterized in nonneuronal systems, little is known about its signaling role during CNS development. Results: In response to uPA, neuronal migration and neuritogenesis are promoted in a dosedependent manner. After stimulation, uPAR interacts with a 5 -and b 1 -integrin subunits, which may constitute an abheterodimer that acts as a uPA-uPAR coreceptor favoring the activation of multiple kinases. This interaction may be responsible for the uPA-promoted phosphorylation of focal adhesion kinase (FAK) and its relocation toward growth cones, triggering cytoskeletal reorganization which, in turn, induces morphological changes related to neuronal migration and neuritogenesis. Conclusions: uPA has a key role during CNS development. In association with its receptor, it orchestrates both proteolytic and nonproteolytic events that govern the proper formation of neural networks. Developmental Dynamics 243:676-689, 2014. V C 2014 Wiley Periodicals, Inc.

Background: Cell proliferation plays an important morphogenetic role. This work analyzes the temporalspatial organization of cell proliferation as an attempt to understand its contribution to the chick optic tectum (OT) morphogenesis. Results: A morphogenetic model based on space-dependent differences in cell proliferation is presented. Step1: a medial zone of high mitotic density (mZHMD) appears at the caudal zone. Step2: the mZHMD expands cephalically forming the dorsal curvature and then duplicates into two bilateral ZHMDs (bZHMD). Step3: the bZHMDs move toward the central region of each hemitectum. Step4: the planar expansion of both bZHMD and a relative decrement in the dorsal midline growth produces a dorsal medial groove separating the tectal hemispheres. Step5: a relative caudal displacement of the bZHMDs produces the OT caudal curvature. Numerical sequences derived from records of mitotic cells spatial coordinates, analyzed as stochastic point processes, show that they correspond to 1/f (b) processes. The spatial organization subsumes deterministic and stochastic components. Conclusions: The deterministic component describes the presence of a long-range influence that installs an asymmetric distribution of cell proliferation, i.e., an asymmetrically located ZHMD that print space-dependent differences onto the tectal corticogenesis. The stochastic component reveals short-range anti-correlations reflecting spatial clusterization and synchronization between neighboring cells. Developmental Dynamics 241:1043-1061, 2012. V C 2012 Wiley Periodicals, Inc.Key words: developing CNS; mitotic cell organization; nonlinear analyses; morphogenesis Key findings:The signals representing the mitotic cell spatial organization display 1/f type spectrum. The signals subsume deterministic components that reveal the existence of long-range influences. The signals subsume stochastic fluctuations revealing short-range anti-correlations between adjacent cells. The differential displacements of zones of high mitotic density regulate planar expansion. The asymmetric proliferation prints space-dependent histogenetic changes to the tectal corticogenesis.

Intercellular communication is one of the most important events in cell population behavior. In the last decade, tunneling nanotubes (TNTs) have been recognized as a new form of long distance intercellular connection. TNT function is to allow molecular and subcellular structure exchange between neighboring cells via the transfer of molecules and organelles such as calcium ions, prions, viral and bacterial pathogens, small lysosomes and mitochondria. New findings support the concept that mesenchymal stem cells (MSCs) can affect cell microenvironment by the release of soluble factors or the transfer of cellular components to neighboring cells, in a way which significantly contributes to cell regulation and tissue repair, although the underlying mechanisms remain poorly understood. MSCs have many advantages for their implementation in regenerative medicine. The TNTs in these cell types are heterogeneous in both structure and function, probably due to their highly dynamic behavior. In this work we report an extensive and detailed description of types, structure, components, dynamics and functionality of the TNTs bridging neighboring human umbilical cord MSCs obtained from Wharton"s jelly. Characterization studies were carried out through phase contrast, fluorescence, electron microscopy and time lapse images with the aim of describing cells suitable for an eventual regenerative medicine.