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Acute Brain Slices (acute + brain_slice)
Selected AbstractsDynamics of a Transgene Expression in Acute Rat Brain Slices Transfected with Adenoviral VectorsEXPERIMENTAL PHYSIOLOGY, Issue 4 2003C. E. L. Stokes We present a quantitative account of the expression dynamics of a transgene (enhanced green fluorescent protein, EGFP) in acute brain slices transfected with an adenoviral vector (AVV) under control of the human cytomegalovirus (HCMV) promoter. Micromolar concentrations of EGFP could be detected in brainstem and hippocampal slices as early as 7 h after in vitro transfection with a viral titre of 4.4 × 109 plaque-forming units (pfu) ml,1. Although initially EGFP appeared mainly in glia, it could be detected in neurones with longer incubation times of 10-12 h. However, fluorescence was never detected within some populations of neurones, such as hippocampal pyramidal cells, or within the hypoglossal motor nucleus. The density of cells expressing EGFP peaked at 10 h and then decreased, possibly suggesting that high concentrations of EGFP are toxic. The age of the animal significantly affected the speed of EGFP accumulation: after 10 h of incubation in 30-day-old rats only 4.88 ± 0.51 cells/10 000 ,m2 were fluorescent compared to 7.28 ± 0.39 cells/10 000 ,m2 in 12-day-old rats (P < 0.05). HCMV promoter-driven transgene expression depended on the activity of protein kinase A, and was depressed with a cAMP/protein kinase A antagonist (20 ,M Rp-cAMPS; P < 0.0005). This indicates that expression of HCMV-driven constructs is likely to be skewed towards cellular populations where cAMP-dependent signalling pathways are active. We conclude that acute transfection of brain slices with AVVs within hours causes EGFP expression in micromolar concentrations and that such transfected cells may remain viable for use in physiological experiments. [source] Neuroprotective role of bradykinin because of the attenuation of pro-inflammatory cytokine release from activated microgliaJOURNAL OF NEUROCHEMISTRY, Issue 2 2007Mami Noda Abstract Bradykinin (BK) has been reported to be a mediator of brain damage in acute insults. Receptors for BK have been identified on microglia, the pathologic sensors of the brain. Here, we report that BK attenuated lipopolysaccharide (LPS)-induced release of tumor necrosis factor-alpha (TNF-,) and interleukin-1, from microglial cells, thus acting as an anti-inflammatory mediator in the brain. This effect was mimicked by raising intracellular cAMP or stimulating the prostanoid receptors EP2 and EP4, while it was abolished by a cAMP antagonist, a prostanoid receptor antagonist, or by an inhibitor of the inducible cyclooxygenase (cyclooxygenase-2). BK also enhanced formation of prostaglandin E2 and expression of microsomal prostaglandin E synthase. Expression of BK receptors and EP2/EP4 receptors were also enhanced. Using physiological techniques, we identified functional BK receptors not only in culture, but also in microglia from acute brain slices. BK reduced LPS-induced neuronal death in neuron,microglia co-cultures. This was probably mediated via microglia as it did not affect TNF-,-induced neuronal death in pure neuronal cultures. Our data imply that BK has anti-inflammatory and neuroprotective effects in the central nervous system by modulating microglial function. [source] Methodological aspects of in vitro sensing of L -glutamate in acute brain slicesTHE CHEMICAL RECORD, Issue 6 2007Masao Sugawara Abstract L -Glutamate is a major amino acid neurotransmitter in the central neuronal system of the mammalian brain and plays a vital role in brain development, synaptic plasticity, neurotoxicity, and neuropathological disorders. Despite technical limitations, progress is being made in sensing L -glutamate in vivo and in vitro. Sophisticated microsensors with the necessary spatial and temporal resolution have recently been emerging, which enable us to discern regional distribution, concentration levels, and temporal changes of L -glutamate in acute brain slices. The L -glutamate sensors for in vitro sensing have different structures and sizes, such as glass capillary-based enzyme sensors, polymer-coated enzyme sensors, and patch sensors based on natural sensing probes. The concentration of L -glutamate released in brain slices by chemical stimulation is markedly dependent on neuronal regions, types of stimulation, and sensing methods. Real- and long-time monitoring of L -glutamate in acute hippocampal slices is beginning to shed light on L -glutamate release related to the molecular mechanisms of long-term potentiation. Progress is also being made toward the visualization of L -glutamate release in acute hippocampal slices. The methodological aspects of in vitro sensing of L -glutamate are discussed. © 2007 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 7: 317,325; 2007: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20126 [source] | ||||||||||