Unlabelled: Electrophysiological experiments in the partial cortical isolation ("undercut" or "UC") model of injury-induced neocortical epileptogenesis have shown alterations in GABAergic synaptic transmission attributable to abnormalities in presynaptic terminals. To determine whether the decreased inhibition was associated with structural abnormalities in GABAergic interneurons, we used immunocytochemical techniques, confocal microscopy and EM in UC and control sensorimotor rat cortex to analyze structural alterations in fast-spiking parvalbumin-containing interneurons and pyramidal (Pyr) cells of layer V. Principle findings were: 1) there were no decreases in counts of parvalbumin (PV)- or GABA-immunoreactive interneurons in UC cortex, however there were significant reductions in expression of VGAT and GAD-65 and -67 in halos of GABAergic terminals around Pyr somata in layer V.
View Article and Find Full Text PDFSystemic inflammatory response syndrome (SIRS) is a potentially lethal condition, as it can progress to shock, multi-organ failure, and death. It can be triggered by infection, tissue damage, or hemorrhage. The role of tissue injury in the progression from SIRS to shock is incompletely understood.
View Article and Find Full Text PDFIdiopathic interstitial pneumonias are a group of idiopathic interstitial lung diseases of which idiopathic pulmonary fibrosis (IPF) is the lesion of usual interstitial pneumonia. Although the pathogenic mechanisms remain incompletely understood, disease-specific changes in blood, a readily accessible biospecimen, have not been fully characterized. To identify biomarkers from blood and sera, the immune status of IPF patients and control subjects without structural lung disease was quantified by measuring cell surface markers, mRNA levels, and serum proteins.
View Article and Find Full Text PDFThe sequelae of traumatic brain injury, including posttraumatic epilepsy, represent a major societal problem. Significant resources are required to develop a better understanding of the underlying pathophysiologic mechanisms as targets for potential prophylactic therapies. Posttraumatic epilepsy undoubtedly involves numerous pathogenic factors that develop more or less in parallel.
View Article and Find Full Text PDFAMPA receptors (AMPARs) mediate the bulk of fast synaptic excitation in the CNS. We have recently shown that AMPAR-dependent synaptic transmission in immature neocortical pyramidal neurons is mediated by GluR2-deficient receptors that can be modulated by intra- or extracellular polyamines (PAs). Phosphorylation of AMPARs, e.
View Article and Find Full Text PDFClassification of inhibitory interneurons is critical in determining their role in normal information processing and pathophysiological conditions such as epilepsy. Classification schemes have relied on morphological, physiological, biochemical, and molecular criteria; and clear correlations have been demonstrated between firing patterns and cellular markers such as neuropeptides and calcium-binding proteins. This molecular diversity has allowed generation of transgenic mouse strains in which GFP expression is linked to the expression of one of these markers and presumably a single subtype of neuron.
View Article and Find Full Text PDFEpiscleral vein cauterization (EVC) is used in rats to generate a glaucoma model with high intraocular pressure (IOP). The long-term retinal damage in this glaucoma model, however, has not been accurately quantified. We report the location and amount of retinal ganglion cell (RGC) damage caused by (EVC) induced IOP elevation in two rat strains.
View Article and Find Full Text PDFAlpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptors (AMPARs) mediate the majority of fast excitation in the CNS. Receptors lacking GluR2 exhibit inward rectification and paired-pulse facilitation (PPF) due to polyamine (PA)-dependent block and unblock, respectively. In this study, we tested whether rectification and PPF in immature, but not mature, pyramidal neurons depend not only on the absence of functional GluR2 but also on the level of endogenous PAs.
View Article and Find Full Text PDFInvest Ophthalmol Vis Sci
September 2004
Purpose: To determine the effect of intraocular pressure (IOP) elevation on glutamate-induced expression of glutamine synthetase (GS) in retinal Müller cells of rat eyes.
Methods: Six groups of three rats each were studied. Group I was a normal control group.
Extracellular levels of glutamate are thought to be increased in glaucoma and thus contribute to retinal damage. An increase in glutamate concentration or duration in the extracellular retinal space is expected to impact glutathione content in Müller cells since glutamate is the rate-limiting constituent in glutathione synthesis. We have investigated whether glutathione content is changed in retinal Müller cells of monkeys with experimental glaucoma using immunocytochemistry and image analysis.
View Article and Find Full Text PDFPurpose: To quantify the extent and pattern of retinal ganglion cell (RGC) loss in the DBA2/NNia glaucomatous mouse strain as a function of age and compare it with ganglion cell loss in a nonglaucomatous strain.
Methods: All the ganglion cells in retinas of DBA/2NNia and C57/BL6 mice of various ages (five eyes per age group in 3-month intervals from 3 to 18 months of age) were counted. A novel counting method that does not rely on sampling and that uses retrograde labeling of RGCs with Fluorogold (Fluorochrome; Englewood, CO) was used.
Invest Ophthalmol Vis Sci
August 2002
Purpose: To investigate the hypothesis that the pathophysiology for the death of retinal ganglion cells in glaucoma involves excitotoxic effects from elevated concentrations of vitreal glutamate.
Methods: Experimental glaucoma was induced in the right eyes of 18 rhesus monkeys by argon laser treatments to the trabecular meshwork. After significant visual field defects and/or typical clinical glaucomatous changes had developed (1.
Purpose: To determine the number and cytoarchitecture of retinal ganglion cells (RGCs) in the female Wistar rat, by using a newly devised procedure for rapid RGC counting in the entire retina that avoids assumptions about RGC spatial arrangement.
Methods: RGCs of normal female Wistar rats were retrogradely labeled with a fluorescent tracer. Automated counting was accomplished by applying standard imaging software to analysis of all labeled cells in retinal flatmounts.