Polylactide-glycolide (PLGA) nanoparticles have been developed as pulmonary drug delivery carriers. To investigate their behavior, small- (d50 = 74 nm) and large-sized (d50 = 250 nm) FITC-conjugated PLGA nanoparticles were intratracheally administered to rats and were traced for 5, 30 and 60 minutes and 24 hours after administration (HAT). Immunohistochemically, a, FITC-positive ...

AIMS: To evaluate, immunohistochemically, the presence and distribution of lubricin in human temporomandibular joint (TMJ) discs without any degenerative changes, obtained from autopsies, in order to elucidate the TMJ lubrication system and disc tribology. METHODS: Immunohistochemistry for lubricin detection was carried out on 34 TMJ discs. Any disc had signs ...

Disulfiram is an aldehyde dehydrogenase inhibitor used for the treatment of alcohol dependence and of cocaine addiction. It has been demonstrated that subchronic administration of disulfiram or N,N-diethyldithiocarbamate (DEDTC), the main derivative of disulfiram, to rats can produce central-peripheral distal axonopathy. However, few data regarding the axonal effects of these ...

The establishment and maintenance of cell polarity requires targeted recruitment of polarity regulators to the plasma membrane. Phosphatidylserine is now shown to have a key role in polarization of yeast cells and the localization of the central polarity regulator Cdc42.

In Digelasinus diversipes, spermatozoa are maintained in bundles, with 74 spermatozoa on average, in the seminal vesicle. These spermatozoa are very short (20 μm) and consist of a head and flagellum. The head includes an acrosome (perforatorium covered by the acrosomal vesicle) and a nucleus. A regular electron-lucent region separates ...

Regeneration of myelin sheaths (remyelination) after central nervous system demyelination is important to restore saltatory conduction and to prevent axonal loss. In multiple sclerosis, the insufficiency of remyelination leads to the irreversible degeneration of axons and correlated clinical decline. Therefore, a regenerative strategy to encourage remyelination may protect axons and ...

STUDY OBJECTIVE: To better understand the precise role of sensory corpuscles within the female external genitalia. DESIGN: After IRB approval, waste tissue samples were obtained from 10 normal girls (aged 2-9 years) who underwent surgery for labial fusion. Immunocytochemistry against protein gene product 9.5 (PGP 9.5), neuron-specific enolase (NSE), vasoactive ...

Myelinated axons are a beautiful example of symbiotic interactions between two cell types: Myelinating glial cells organize axonal membranes and build their myelin sheaths to allow fast action potential conduction, while axons regulate myelination and enhance the survival of myelinating cells. Axonal demyelination, occurring in neurodegenerative diseases or after a ...

SummaryThe selection of competent oocytes for in vitro maturation is still a major problem during bovine in vitro embryo production. Markers for in vitro cytoplasmic maturation, based on the organization of cortical granule and mitochondria, are lacking. We examined the pre-selection of immature bovine oocytes by brilliant cresyl blue stain ...

The actin cytoskeleton in the mature female gametophyte of angiosperms has been examined in only a few dicot and monocot species. The main purposes of this study were to identify how the actin cytoskeleton is arranged in the mature extra-ovular embryo sac in Utricularia nelumbifolia (Lentibulariaceae). We found that the ...

Assembly of a cytokinetic contractile ring is a form of cell polarization in which the equatorial cell cortex becomes differentiated from the polar regions. Microtubules direct cytokinetic polarization via the central spindle and astral microtubules. The mechanism of central spindle-directed furrow formation is reasonably well understood, but the aster-directed pathway ...

Many primary vestibular afferents form large cup-shaped postsynaptic terminals (calyces) that envelope the basolateral surfaces of type I hair cells. The calyceal terminals both respond to glutamate released from ribbon synapses in the type I cells and initiate spikes that propagate to the afferent's central terminals in the brainstem. The ...

To present cytokeratin (CK)7 (OV-TL 12/30 clone) as a newly identified, reliable marker for distinguishing between the conjunctival and corneal surface epithelia, which will contribute to the precise diagnosis of limbal stem cell deficiency (LSCD). Corneal and conjunctival epithelial imprints from 12 cadaveric bulbi and from 9 patients with clinically ...

After glutaraldehyde fixation followed by osmium tetroxide postfixing, the secretory granules of acinar cells in male hamster submandibular glands (SGs) exhibit a characteristic bipartite substructure, with an electron-lucid rim and a more electron-dense central core. In female hamsters, the reverse is seen, with the larger portion of the granules forming ...

• Premise of the study: Oaks are dominant trees and key species in many temperate and subtropical forests in the world. In this study, we analyzed patterns of distribution of red oaks (Quercus, section Lobatae) occurring in Mexico and Central America to determine areas of species richness and endemism to ...

Background/Aims:D-aspartate is an important candidate for retinal neurotransmitter or neuromodulator. The purpose of this study was to investigate the cells type and distribution of the D-aspartate-immunopositive cells in the ganglion cell layer. Methods: Wister rats were fixed by perfusion with 5% glutaraldehyde. Paraffin sections of the retina were immunohistochemically double-labeled ...

The TonoPen applanation tonometry is an established method for intraocular pressure (IOP) measurement. The IOP is one of the main variables affecting retinal ganglion cell (RGC) loss in experimental animal models in ophthalmology and the main risk factor for human glaucoma. In this study, we examined if IOP measurements with ...

The failure of the adult mammalian retina to regenerate can be partly attributed to the barrier formed by inhibitory extracellular matrix (ECM) and cell adhesion molecules, such as CD44 and neurocan, after degeneration. These molecules act to separate a sub-retinal graft from integrating into the host retina. It has been ...

Crocetin is a carotenoid that is the aglicone of crocin, which are found in saffron stigmas (Crocus sativus L.) and gardenia fruit (Gardenia jasminoides Ellis). In this study, we investigated the effects of crocetin on retinal damage. To examine whether crocetin affects stress pathways, we investigated intracellular oxidation induced by ...

Retinal ganglion cells exhibit substantial correlated firing: a tendency to fire nearly synchronously at rates different from those expected by chance. These correlations suggest that network interactions significantly shape the visual signal transmitted from the eye to the brain. This study describes the degree and structure of correlated firing among ...

Here we review evidence that loss of photoreceptors due to degenerative retinal disease causes an increase in the rate of spontaneous ganglion spike discharge. Information about persistent spike activity is important since it is expected to add noise to the communication between the eye and the brain and thus impact ...

Retinal ganglion cells that respond selectively to a dark spot on a brighter background (OFF cells) have smaller dendritic fields than their ON counterparts and are more numerous. OFF cells also branch more densely, and thus collect more synapses per visual angle. That the retina devotes more resources to processing ...

The heterozygous mutation B6;C3-Opa1(Q285STOP), which models autosomal dominant optic atrophy, leads to a 50% reduction in Opa1 transcript and protein in the mouse retina and neural tissues and is associated with visual dysfunction and structural changes in the murine retina and optic nerve. In this article we use this model ...

Retinal ischemia-reperfusion causes capillary degeneration but the mechanisms of damage are not well understood. The NMDA receptor plays an important role in neuronal damage after ischemia-reperfusion. Therefore, we determined whether retinal blood vessels are damaged structurally and functionally in a rat model of retinal degeneration induced by NMDA. At 7 ...

We examined the degeneration of post-mitotic ganglion cells in ex-vivo neonatal retinal explants following axon damage. Ultrastructural features of both apoptosis and autophagy were detected. Degenerating cells reacted with antibodies specific for activated caspase-3 or -9, consistent with the presence of caspase activity. Furthermore, peptidic inhibitors of caspase-9, -6 or ...

Working at the nanoscale means to completely rethink how to approach engineering in the body in general and in the eye in particular. In nanomedicine, tissue engineering is the ability to influence an environment either by adding, subtracting or manipulating that environment to allow it to be more conducive for ...

Mutations in ANT, a mitochondrial ATP transporter, are typically associated with myopathy. Because of the high metabolic demands of the retina, the authors examined whether elimination of the Ant1 isoform in a transgenic mouse affects retinal function or morphology. RT-PCR was used to confirm Ant1 expression in retinas of wild-type ...

Primary open-angle glaucoma (POAG) is one of the three principal subtypes of glaucoma and among the leading cause of blindness worldwide. POAG is defined by cell death of the retinal ganglion cells (RGCs) and surrounding neuronal cells at higher or normal intraocular pressure (IOP). Coded by one of the three ...

Melanopsin is the photopigment of intrinsically photosensitive retinal ganglion cells (ipRGCs). Melanopsin immunoreactivity reveals two dendritic plexuses within the inner plexiform layer (IPL) and morphologically heterogeneous retinal ganglion cells. Using enhanced immunohistochemistry, we provide a fuller description of murine cell types expressing melanopsin, their contribution to the plexuses of melanopsin ...

BACKGROUND: Retinal diseases such as age-related macular degeneration and retinitis pigmentosa remain major causes of severe vision loss in humans. Clinical trials for treatment of retinal degenerations are underway and advancements in our understanding of retinal biology in health/disease have implications for novel therapies. METHODS: A review of retinal biology ...

Melanopsin is the photopigment of intrinsically photosensitive retinal ganglion cells (ipRGCs). Melanopsin immunoreactivity reveals two dendritic plexuses within the inner plexiform layer (IPL) and morphologically heterogeneous retinal ganglion cells. Using enhanced immunohistochemistry, we provide a fuller description of murine cell types expressing melanopsin, their contribution to the plexuses of melanopsin ...

The retina is constantly exposed to ultraviolet (UV) light with different wavelengths, which may lead to chronic UV-induced retinal injury. In our previous studies, we have shown the protective effects of pituitary adenylate cyclase activating polypeptide (PACAP) in toxic and ischemic retinal injuries. The aim of the present study was ...

Converting inner retinal neurons to photosensitive cells by expressing channelrhodopsin-2 (ChR2) offers a novel approach for treating blindness caused by retinal degenerative diseases. In the present study, the recombinant adeno-associated virus serotype 2 (rAAV2)-mediated expression and function of a fusion construct of channelopsin-2 (Chop2) and green fluorescent protein (GFP) (Chop2-GFP) ...

Wolfberry (fruit of Lycium barbarum Linn) has been known for balancing 'Yin' and 'Yang' in the body, nourishing the liver and kidney, improving visual acuity for more than 2,500 years in oriental countries. The active components in wolfberry include L. barbarum polysaccharide (LBP), zeaxanthine, betaine, cerebroside and trace amounts of ...

There has been growing interest in the use of retinal imaging for tracking disease progression in multiple sclerosis. However, systematic and detailed pathological descriptions of retinal tissue in multiple sclerosis are lacking. Graded, histological evaluations on eyes from 82 patients with multiple sclerosis and 10 subjects with other neurological diseases, ...

The retinal ganglion cell layer of the eye comprises a subtype of cells characterized by their intrinsic photosensitivity and expression of melanopsin (ipRGCs). These cells regulate a variety of non-image-forming (NIF) functions such as light entrainment of circadian rhythms, acute suppression of locomotor activity (masking), and pupillary light reflex. Two ...

Natriuretic peptides (NPs) exert their actions through three membrane-bound receptors, which are known as NP receptors (NPRs: NPR-A, NPR-B and NPR-C). In this work we examined the expression of three NPRs in rat retinal ganglion cells (GCs), retrogradely labeled and intracellularly dye-injected, by double immunofluorescence labeling. In vertical sections, almost ...

PURPOSE. In Old World primates, the retina receives input from histaminergic neurons in the posterior hypothalamus. They are a subset of the neurons that project throughout the central nervous system and fire maximally during the day. The contribution of these neurons to vision, was examined by applying histamine to a ...

Early retinal studies categorized ganglion cell behavior as either linear or nonlinear and rectifying as represented by the familiar X- and Y-type ganglion cells in cat. Nonlinear behavior is in large part a consequence of the rectifying nonlinearities inherent in synaptic transmission. These nonlinear signals underlie many special functions in ...

The anti-epileptic drug vigabatrin induces an irreversible constriction of the visual field, but is still widely used to treat infantile spasms and some forms of epilepsy. We recently reported that vigabatrin-induced cone damage is due to a taurine deficiency. However, optic atrophy and thus retinal ganglion cell degeneration was also ...

Ouabain is both a cardiac glycoside used in therapy of congestive heart failure and an endogenous steroid hormone. It specifically binds to Na(+), K(+)-ATPase (NKA) and blocks its activity. Overdose of ouabain induces retinal damage. In different species ouabain-induced retinal degeneration affects different cell types. In fish and rabbit ouabain ...

The same visual stimulus evokes a different pattern of neural signals each time the stimulus is presented. Because this unreliability reduces visual performance, it is important to understand how it arises from neural circuitry. We asked whether different types of ganglion cell receive excitatory signals with different reliability and frequency ...

Extracellular and whole-cell light-evoked responses of mouse retinal ganglion cells were recorded in the presence of the mGluR8 selective agonist, (S)-3,4-dicarboxy-phenylglycine (DCPG). Off-light responses were reversibly reduced in the presence of DCPG in wild-type but not in mGluR8-deficient retinas. On-responses were only marginally modulated by DCPG. During Off-responses, DCPG suppressed ...

Retinal amacrine cells (ACs) and ganglion cells (GCs) have been shown to display large morphological diversity, and here we show that four types of ACs and three types of GCs exhibit physiologically-distinguishable properties. They are the sustained ON ACs; sustained OFF ACs; transient ON-OFF ACs; transient ON-OFF ACs with wide ...

Regenerative strategies for retinal degenerative diseases are limited by poor cellular survival, distribution and integration after transplantation to the sub-retinal space. To overcome this limitations a stem cell delivery system was developed, taking advantage of the minimally-invasive, injectable and biodegradable properties of a blend of hyaluronan and methylcellulose (HAMC). The ...

Many disabling human retinal disorders involve the central retina, particularly the macula. However, the commonly used rodent models in research, mouse and rat, do not possess a macula. The purpose of this study was to identify small laboratory rodents with a significant central region as potential new models for macular ...

The eyes of three adult male African elephants were examined, the retinas were whole-mounted, stained and analyzed to determine visual acuity. A range of small to large ganglion cell types were observed across the retinas. We observed three regions of high ganglion cell density, one in the upper temporal quadrant, ...

Aging is the greatest risk factor for glaucoma, implying that intrinsic age-related changes to retinal ganglion cells, their supporting tissue or both make retinal ganglion cells susceptible to injury. Changes to the ocular vasculature, connective tissue of the optic nerve head and mitochondria, which have been documented with advancing age ...

A hexagonal electrode configuration has been proposed as an advantageous alternative to conventional electrode arrangements used in retinal prosthesis design. In the present study, the aim was to characterize retinal ganglion cell axonal responses to epiretinal electrical stimulation. 50 and 125 µm disk electrodes, arranged in a hexagonal configuration, were ...

A continuum network model of the retina is presented, consisting of an active implementation of the retinal ganglion cell tissue layer and passive implementation of deeper cell layers. The retinal ganglion cell layer receives excitatory presynaptic inputs from the bipolar layer and inhibitory presynaptic inputs from the amacrine layer. Simulations ...