Investigation of retinal neurochemistry in a well-defined chick model form-deprivation myopia indicated that dopamine and its metabolite 3,4-dihydroxyphenylacetic acid are reduced myopic as compared to control eyes. The reduction is evident only during light adaptation accompanied by decreased rate biosynthesis. To test whether the alteration metabolism related eye growth, agents known interact with receptors were administered locally deprived Remarkably, expected growth axial dimension was...

Parkinson9s disease (PD) is a progressive neurodegenerative disorder that characterized by the loss of dopamine neurons in substantia nigra pars compacta, culminating severe motor symptoms, including resting tremor, rigidity, bradykinesia, and postural instability. In addition to deficits, there are variety nonmotor symptoms associated with PD. These generally precede onset sometimes years, include anosmia, problems gastrointestinal motility, sleep disturbances, sympathetic denervation,...

Dopamine is a key neuromodulator in the retina and brain that supports motor, cognitive, visual function. Here, we developed mouse model on C57 background which expression of rate-limiting enzyme for dopamine synthesis, tyrosine hydroxylase, specifically disrupted retina. This enabled assessment overall role retinal vision using electrophysiological (electroretinogram), psychophysical (optokinetic tracking), pharmacological techniques. Significant disruptions were observed high-resolution,...

Rat fibroblasts were infected with a retroviral vector containing the cDNA for rat tyrosine hydroxylase [TH; 3-monooxygenase; L-tyrosine, tetrahydropteridine:oxygen oxidoreductase (3-hydroxylating), EC 1.14.16.2]. A TH-positive clone was identified by biochemical assay and immunohistochemical staining. When supplemented in vitro pterin cofactors required TH activity, these cells produced L-dopa released it into cell culture medium. Uninfected control grafted separately to caudate of rats...

Abstract The avian retina and pineal gland contain autonomous circadian oscillators photo‐entrainment pathways, but the photopigment(s) that mediate entrainment have not been definitively identified. Melanopsin ( Opn4 ) is a novel opsin involved in of rhythms mammals. Here, we report cDNA cloning chicken melanopsin show its expression retina, brain gland. Like melanopsins identified amphibians mammals, more similar to invertebrate retinaldehyde‐based photopigments than typically found...

Abstract The normal postnatal development, the influence of age, and effects visual deprivation on dopamine system in retina rhesus monkeys were examined. lowest level retinal was found at birth. By 3–4 weeks concentration had more than doubled. This remained relatively constant retinas older infants adult up to 34 yr age. metabolite 3,4-dihydroxyphenylacetic acid (DOPAC) activity tyrosine hydroxylase did not significantly change as a function age during life span. Monocular occlusion...

Dopamine (DA) functions as an essential neuromodulator in the brain and retina such that disruptions dopaminergic system are associated with common neurologic disorders Parkinson's disease. Although a reduction DA content has been observed diabetes, its effects development of diabetes-induced neuropathy remains unknown. Because is rich well known pathology (diabetic retinopathy or DR), this study was designed to examine role retinal deficiency early visual defects DR. Using rodent models...

A clear demonstration of the role melatonin and its receptors in specific retinal functions is lacking. The present study investigated distribution MT1 within retina, scotopic photopic electroretinograms (ERG) morphology wild-type (WT) receptor-deficient mice. receptor transcripts were localized photoreceptor cells some inner neurons. diurnal rhythm dark-adapted ERG responses was observed WT mice, with higher a- b-wave amplitudes at night, but this absent mice lacking receptors. Injection...

Purpose: Exposure to high-intensity or outdoor lighting has been shown decrease the severity of myopia in both human epidemiological studies and animal models. Currently, it is not fully understood how light interacts with visual signaling impact myopia. Previous work performed mouse retina demonstrated that functional rod photoreceptors are needed develop experimentally-induced myopia, alluding an essential role for refractive development. Methods: To determine whether dim rod-dominated...

Abstract In mammals a subpopulation of retinal ganglion cells are intrinsically photosensitive (ipRGCs), express the photopigment melanopsin, and play an important role in regulation nonimage‐forming visual system. We have recently reported that melanopsin mRNA protein levels rat retina under photic circadian control. The aim present work was to investigate mechanisms control expression retina. discovered dopamine (DA) is involved mRNA, possibly via D 2 receptors located on these ipRGCs....

Clock genes are known to be the molecular core of biological clocks vertebrates. They expressed not only in those tissues considered central pacemakers, but also peripheral tissues. In present study, partial cDNAs for 6 principal clock (Period 1-3 and Cryptochrome 1-3) were cloned from a teleost fish, goldfish (Carassius auratus ). These showed high homology (approximately 90%) with respective zebrafish (Danio rerio), other which have been cloned. The daily expression pattern each gene...

Melatonin modulates many important functions within the eye by interacting with a family of G-protein-coupled receptors that are negatively coupled adenylate cyclase. In mouse, Receptors type 1 (MT1) mRNAs have been localized to photoreceptors, inner retinal neurons, and ganglion cells, thus suggesting MT1 may play an role in physiology. Indeed, we recently reported absence has dramatic effect on regulation daily rhythm visual processing, cell viability during aging. We also shown removal...

Atropine, a muscarinic antagonist, is known to inhibit myopia progression in several animal models and humans. However, the mode of action not established yet. In this study, we compared quantitative iTRAQ proteomic analysis retinas collected from control lens-induced myopic (LIM) mouse eyes treated with atropine. The group received (−15D) spectacle lens over right eye on postnatal day 10 or without atropine drops starting 24. Axial length was measured by optical low coherence interferometry...

Dopamine is a retinal neuromodulator that has been implicated in many aspects of physiology. Photoreceptor cells express dopamine D4 receptors regulate cAMP metabolism. To assess the effects on photoreceptor physiology, we examined morphology, electrophysiology, and regulation metabolism mice with targeted disruption receptor gene. morphology outer segment disc shedding after light onset were normal knock-out (D4KO) mice. Quinpirole, D2/D3/D4 agonist, decreased synthesis retinas wild-type...

Abstract Many aspects of photoreceptor metabolism are regulated as diurnal or circadian rhythms. The nature the signals that drive rhythms in mouse photoreceptors is unknown. Dopamine amacrine cells retina express core clock genes, leading us to test hypothesis dopamine regulates protein phosphorylation cells. To this end we investigated phosducin, an abundant photoreceptor‐specific phosphoprotein. In mice exposed a daily light–dark cycle, robust phosducin and retinal were observed....

Because of the retina's role in refractive development, this study was conducted to analyze retinal transcriptome chicks wearing a spectacle lens, well-established means inducing errors, identify gene expression alterations and develop novel mechanistic hypotheses about development.One-week-old white Leghorn wore unilateral lens +15 or -15 D for 6 hours 3 days. With total RNA from retina/(retinal pigment epithelium, RPE), chicken microarrays were used compare levels between lens-wearing...