156 research outputs found
RURAL DEVELOPMENT PROGRAMS IN THE NEXT FARM BILL
Community/Rural/Urban Development,
Richard Wagner\u27s Jesus von Nazareth
In addition to his renowned musical output, Richard Wagner produced a logorrhoeic prose oeuvre, including a dramatic sketch of the last weeks of the life of Jesus Christ entitled Jesus von Nazareth. Though drafted in 1848-1849, it was published only posthumously, and has therefore been somewhat neglected in the otherwise voluminous Wagnerian literature. This thesis first examines the origins of Jesus von Nazareth amidst the climate of revolution wherein it was conceived, ascertaining its place within Wagner’s own internal development and amongst the radical thinkers who influenced it. While Ludwig Feuerbach has traditionally been seen as the most prominent of these, this thesis examines Wagner’s sources more broadly. The thesis then summarizes and analyzes Jesus von Nazareth itself, particularly in terms of Wagner’s use of biblical scripture. The thesis demonstrates how his not infrequent misuse thereof constitutes one way in which Wagner transmogrifies Jesus as mutable lens through which his own ideology of social revolution is reflected. It also attempts to provide a critical assessment of the relative dramatic merits of Jesus von Nazareth and looks into Wagner’s ultimate decision not to complete the work. The thesis then briefly summarizes the changes that occurred in Wagner’s mature Christological outlook subsequent to his drafting of Jesus von Nazareth, attempting to concisely demonstrate some developments beyond Wagner’s well-known encounter with the philosophy of Arthur Schopenhauer. The thesis concludes with an evaluation of how Jesus von Nazareth informed Wagner’s general religious outlook and the extent to which this worldview is a productive one
Boosting of Synaptic Potentials and Spine Ca Transients by the Peptide Toxin SNX-482 Requires Alpha-1E-Encoded Voltage-Gated Ca Channels
The majority of glutamatergic synapses formed onto principal neurons of the mammalian central nervous system are associated with dendritic spines. Spines are tiny protuberances that house the proteins that mediate the response of the postsynaptic cell to the presynaptic release of glutamate. Postsynaptic signals are regulated by an ion channel signaling cascade that is active in individual dendritic spines and involves voltage-gated calcium (Ca) channels, small conductance (SK)-type Ca-activated potassium channels, and NMDA-type glutamate receptors. Pharmacological studies using the toxin SNX-482 indicated that the voltage-gated Ca channels that signal within spines to open SK channels belong to the class CaV2.3, which is encoded by the Alpha-1E pore-forming subunit. In order to specifically test this conclusion, we examined the effects of SNX-482 on synaptic signals in acute hippocampal slices from knock-out mice lacking the Alpha-1E gene. We find that in these mice, application of SNX-482 has no effect on glutamate-uncaging evoked synaptic potentials and Ca influx, indicating that that SNX-482 indeed acts via the Alpha-1E-encoded CaV2.3 channel
Developmental mapping of small-conductance calcium-activated potassium channel expression in the rat nervous system
Early electrical activity and calcium influx regulate crucial
aspects of neuronal development. Small-conductance calcium-
activated potassium (SK) channels regulate action
potential firing and shape calcium influx through feedback
regulation in mature neurons. These functions, observed in
the adult nervous system, make them ideal candidates to
regulate activity- and calcium-dependent processes in neurodevelopment.
However, to date little is known about the
onset of expression and regions expressing SK channel subunits
in the embryonic and postnatal development of the
central nervous system (CNS). To allow studies on the contribution
of SK channels to different phases of development
of single neurons and networks, we have performed a
detailed in situ hybridization mapping study, providing comprehensive
distribution profiles of all three SK subunits
(SK1, SK2, and SK3) in the rat CNS during embryonic and
postnatal development. SK channel transcripts are
expressed at early stages of prenatal CNS development.
The three SK channel subunits display different developmental
expression gradients in distinct CNS regions, with time
points of expression and up- or downregulation that can be
associated with a range of diverse developmental events.
Their early expression in embryonic development suggests
an involvement of SK channels in the regulation of developmental
processes. Additionally, this study shows how the
postnatal ontogenetic patterns lead to the adult expression
map for each SK channel subunit and how their coexpression
in the same regions or neurons varies throughout
development
Control of Ca2+ Influx and Calmodulin Activation by SK-Channels in Dendritic Spines
© 2016 Griffith et al. The key trigger for Hebbian synaptic plasticity is influx of Ca2+ into postsynaptic dendritic spines. The magnitude of [Ca2+] increase caused by NMDA-receptor (NMDAR) and voltage-gated Ca2+ -channel (VGCC) activation is thought to determine both the amplitude and direction of synaptic plasticity by differential activation of Ca2+ -sensitive enzymes such as calmodulin. Ca2+ influx is negatively regulated by Ca2+ -activated K+ channels (SK-channels) which are in turn inhibited by neuromodulators such as acetylcholine. However, the precise mechanisms by which SK-channels control the induction of synaptic plasticity remain unclear. Using a 3-dimensional model of Ca2+ and calmodulin dynamics within an idealised, but biophysically-plausible, dendritic spine, we show that SK-channels regulate calmodulin activation specifically during neuron-firing patterns associated with induction of spike timing-dependent plasticity. SK-channel activation and the subsequent reduction in Ca2+ influx through NMDARs and L-type VGCCs results in an order of magnitude decrease in calmodulin (CaM) activation, providing a mechanism for the effective gating of synaptic plasticity induction. This provides a common mechanism for the regulation of synaptic plasticity by neuromodulators
Biphasic Synaptic Ca Influx Arising from Compartmentalized Electrical Signals in Dendritic Spines
Dendritic spines compartmentalize synaptically-evoked biochemical signals. The authors show that electrical compartmentalization provided by a spine endows the associated synapse with additional modes of calcium signaling by shaping the kinetics of synaptic calcium currents
Intratumoral virotherapy with 4-1BBL armed modified vaccinia Ankara eradicates solid tumors and promotes protective immune memory
Background Human cancers are extraordinarily heterogeneous in terms of tumor antigen expression, immune infiltration and composition. A common feature, however, is the host ' s inability to mount potent immune responses that prevent tumor growth effectively. Often, naturally primed CD8(+) T cells against solid tumors lack adequate stimulation and efficient tumor tissue penetration due to an immune hostile tumor microenvironment.
Methods To address these shortcomings, we cloned tumor-associated antigens (TAA) and the immune-stimulatory ligand 4-1BBL into the genome of modified vaccinia Ankara (MVA) for intratumoral virotherapy.
Results Local treatment with MVA-TAA-4-1BBL resulted in control of established tumors. Intratumoral injection of MVA localized mainly to the tumor with minimal leakage to the tumor-draining lymph node. In situ infection by MVA-TAA-4-1BBL triggered profound changes in the tumor microenvironment, including the induction of multiple proinflammatory molecules and immunogenic cell death. These changes led to the reactivation and expansion of antigen-experienced, tumor-specific cytotoxic CD8(+) T cells that were essential for the therapeutic antitumor effect. Strikingly, we report the induction of a systemic antitumor immune response including tumor antigen spread by local MVA-TAA-4-1BBL treatment which controlled tumor growth at distant, untreated lesions and protected against local and systemic tumor rechallenge. In all cases, 4-1BBL adjuvanted MVA was superior to MVA.
Conclusion Intratumoral 4-1BBL-armed MVA immunotherapy induced a profound reactivation and expansion of potent tumor-specific CD8(+) T cells as well as favorable proinflammatory changes in the tumor microenvironment, leading to elimination of tumors and protective immunological memory
Selective Phosphorylation Modulates the PIP2 Sensitivity of the CaM-SK Channel Complex
Phosphatidylinositol bisphosphate (PIP2) regulates the activities of many membrane proteins including ion channels through direct interactions. However, the affinity of PIP2 is so high for some channel proteins that its physiological role as a modulator has been questioned. Here we show that PIP2 is an important cofactor for activation of small conductance Ca2+-activated potassium channels (SK) by Ca2+-bound calmodulin (CaM). Removal of the endogenous PIP2 inhibits SK channels. The PIP2-binding site resides at the interface of CaM and the SK C-terminus. We further demonstrate that the affinity of PIP2 for its target proteins can be regulated by cellular signaling. Phosphorylation of CaM T79, located adjacent to the PIP2-binding site, by Casein Kinase 2 reduces the affinity of PIP2 for the CaM-SK channel complex by altering the dynamic interactions among amino acid residues surrounding the PIP2-binding site. This effect of CaM phosphorylation promotes greater channel inhibition by G-protein-mediated hydrolysis of PIP2
- …