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ENeuro Jun 2024Elevated intraocular pressure (IOP) triggers glaucoma by damaging the output neurons of the retina called retinal ganglion cells (RGCs). This leads to the loss of RGC...
Elevated intraocular pressure (IOP) triggers glaucoma by damaging the output neurons of the retina called retinal ganglion cells (RGCs). This leads to the loss of RGC signaling to visual centers of the brain such as the dorsolateral geniculate nucleus (dLGN), which is critical for processing and relaying information to the cortex for conscious vision. In response to altered levels of activity or synaptic input, neurons can homeostatically modulate postsynaptic neurotransmitter receptor numbers, allowing them to scale their synaptic responses to stabilize spike output. While prior work has indicated unaltered glutamate receptor properties in the glaucomatous dLGN, it is unknown whether glaucoma impacts dLGN inhibition. Here, using DBA/2J mice, which develop elevated IOP beginning at 6-7 months of age, we tested whether the strength of inhibitory synapses on dLGN thalamocortical relay neurons is altered in response to the disease state. We found an enhancement of feed-forward disynaptic inhibition arising from local interneurons along with increased amplitude of quantal inhibitory synaptic currents. A combination of immunofluorescence staining for the GABA-α1 receptor subunit, peak-scaled nonstationary fluctuation analysis, and measures of homeostatic synaptic scaling pointed to an approximately 1.4-fold increase in GABA receptors at post-synaptic inhibitory synapses, although several pieces of evidence indicate a non-uniform scaling across inhibitory synapses within individual relay neurons. Together, these results indicate an increase in inhibitory synaptic strength in the glaucomatous dLGN, potentially pointing toward homeostatic compensation for disruptions in network and neuronal function triggered by increased IOP. Elevated eye pressure in glaucoma leads to loss of retinal outputs to the dorsolateral geniculate nucleus (dLGN), which is critical for relaying information to the cortex for conscious vision. Alterations in neuronal activity, as could arise from excitatory synapse loss, can trigger homeostatic adaptations to synaptic function that attempt to maintain activity within a meaningful dynamic range, although whether this occurs uniformly at all synapses within a given neuron or is a non-uniform process is debated. Here, using a mouse model of glaucoma, we show that dLGN inhibitory synapses undergo non-uniform upregulation due to addition of post-synaptic GABA receptors. This is likely to be a neuronal adaptation to glaucomatous pathology in an important sub-cortical visual center.
PubMed: 38937109
DOI: 10.1523/ENEURO.0263-24.2024 -
PloS One 2024To evaluate structural alterations and healing responses in the trabecular meshwork region with optical coherence tomography (AS-OCT) following after gonioscopy assisted...
PURPOSE
To evaluate structural alterations and healing responses in the trabecular meshwork region with optical coherence tomography (AS-OCT) following after gonioscopy assisted transluminal trabeculotomy (GATT) and microincisional trabeculectomy (MIT).
METHODS
73 eyes of 67 patients (M:F = 45:22) with ≥6 months of follow-up after MIT (n = 41) or GATT (n = 32) with or without combined cataract surgery were included for this prospective study. The angle as seen on AS-OCT at 1, 3, 6 months after surgery were evaluated for structural alterations like peripheral anterior synechiae (PAS), hyphema, and hyperreflective scarring responses. The scarring was graded according to the linear extent measured from the centre of the trabecular meshwork (TM) gutter to the sclera/cornea as mild (<250μ), moderate (250-500μ), and severe(˃500μ), while the pattern of scarring was graded as open saucer/gutter, closed gutter, and trench pattern. The association of the need for medication or surgical outcome and clinical variables and AS-OCT parameters including the pattern and severity of scarring were analysed using multivariate regression.
RESULTS
All eyes achieved significant reduction of IOP and number of medications with a final IOP of 15±3.2mm Hg at a mean follow-up of 8±32. months. While mild scarring was seen more common in MIT, severe scarring was seen in >65% of GATT eyes compared to 31% of MIT eye, p<0.001. An open saucer was equally seen in MIT and GATT while the trench pattern was more commonly seen in GATT eyes (>50%). Severe scarring in a trench pattern seemed to predict the need for medications for IOP control, though they independently did not seem to influence the final IOP or surgical outcome.
CONCLUSION
A severe form of scarring in a trench pattern on AS-OCT predicted the need for glaucoma medications after MIGS surgery. Regular monitoring of the scarring responses by AS-OCT and clinical examination are necessary to identify those at need for medications after MIGS.
Topics: Humans; Male; Tomography, Optical Coherence; Female; Aged; Trabeculectomy; Middle Aged; Glaucoma; Prospective Studies; Trabecular Meshwork; Wound Healing; Intraocular Pressure; Gonioscopy; Treatment Outcome
PubMed: 38935644
DOI: 10.1371/journal.pone.0305740 -
PLoS Biology Jun 2024Throughout history, humans have relied on plants as a source of medication, flavoring, and food. Plants synthesize large chemical libraries and release many of these...
Throughout history, humans have relied on plants as a source of medication, flavoring, and food. Plants synthesize large chemical libraries and release many of these compounds into the rhizosphere and atmosphere where they affect animal and microbe behavior. To survive, nematodes must have evolved the sensory capacity to distinguish plant-made small molecules (SMs) that are harmful and must be avoided from those that are beneficial and should be sought. This ability to classify chemical cues as a function of their value is fundamental to olfaction and represents a capacity shared by many animals, including humans. Here, we present an efficient platform based on multiwell plates, liquid handling instrumentation, inexpensive optical scanners, and bespoke software that can efficiently determine the valence (attraction or repulsion) of single SMs in the model nematode, Caenorhabditis elegans. Using this integrated hardware-wetware-software platform, we screened 90 plant SMs and identified 37 that attracted or repelled wild-type animals but had no effect on mutants defective in chemosensory transduction. Genetic dissection indicates that for at least 10 of these SMs, response valence emerges from the integration of opposing signals, arguing that olfactory valence is often determined by integrating chemosensory signals over multiple lines of information. This study establishes that C. elegans is an effective discovery engine for determining chemotaxis valence and for identifying natural products detected by the chemosensory nervous system.
Topics: Caenorhabditis elegans; Animals; Chemotaxis; High-Throughput Screening Assays; Smell; Behavior, Animal; Software
PubMed: 38935621
DOI: 10.1371/journal.pbio.3002672 -
PLoS Biology Jun 2024Loss of synapses between spiral ganglion neurons and inner hair cells (IHC synaptopathy) leads to an auditory neuropathy called hidden hearing loss (HHL) characterized...
Loss of synapses between spiral ganglion neurons and inner hair cells (IHC synaptopathy) leads to an auditory neuropathy called hidden hearing loss (HHL) characterized by normal auditory thresholds but reduced amplitude of sound-evoked auditory potentials. It has been proposed that synaptopathy and HHL result in poor performance in challenging hearing tasks despite a normal audiogram. However, this has only been tested in animals after exposure to noise or ototoxic drugs, which can cause deficits beyond synaptopathy. Furthermore, the impact of supernumerary synapses on auditory processing has not been evaluated. Here, we studied mice in which IHC synapse counts were increased or decreased by altering neurotrophin 3 (Ntf3) expression in IHC supporting cells. As we previously showed, postnatal Ntf3 knockdown or overexpression reduces or increases, respectively, IHC synapse density and suprathreshold amplitude of sound-evoked auditory potentials without changing cochlear thresholds. We now show that IHC synapse density does not influence the magnitude of the acoustic startle reflex or its prepulse inhibition. In contrast, gap-prepulse inhibition, a behavioral test for auditory temporal processing, is reduced or enhanced according to Ntf3 expression levels. These results indicate that IHC synaptopathy causes temporal processing deficits predicted in HHL. Furthermore, the improvement in temporal acuity achieved by increasing Ntf3 expression and synapse density suggests a therapeutic strategy for improving hearing in noise for individuals with synaptopathy of various etiologies.
Topics: Animals; Hair Cells, Auditory, Inner; Synapses; Neurotrophin 3; Mice; Auditory Threshold; Evoked Potentials, Auditory; Reflex, Startle; Auditory Perception; Spiral Ganglion; Female; Male; Hearing Loss, Hidden
PubMed: 38935589
DOI: 10.1371/journal.pbio.3002665 -
Indian Journal of Public Health Oct 2023Because of COVID's impact on social behavior, students have become more reliant on computer-facilitated communication to continue their studies and interact with...
INTRODUCTION
Because of COVID's impact on social behavior, students have become more reliant on computer-facilitated communication to continue their studies and interact with friends. While it is known that the association between screen exposure and psychological well-being is both harmful and stronger among adolescents than younger children, what is less studied are the causal factors that may mediate the relationship.
OBJECTIVES
The objectives of this study were to analyze the relationship between screen exposure and two psychological outcomes, sleep quality and loneliness, using digital eye strain as a mediating factor. Eye strain is expected to have a direct and harmful influence on psychological well-being.
MATERIALS AND METHODS
A structured and validated questionnaire was transcribed and administered online. A nonrepresentative sample of 497 female college students in a North Indian city participated in the study. Digital eye strain, quality of sleep, and feeling of loneliness scores were assessed using latent class analysis.
RESULTS
The selected latent model suggested that Class 2 had a high percentage of students with network issues, the problem with space and noise, and various financial hardships, which had almost doubled the rate of loneliness (53.28%) and sleep-wake difficulties (75.41%) among the students affected with computer vision syndrome (89.75%).
CONCLUSION
There is an urgent need to examine the implications of digital exposure across gender and age to prevent future complications. Further, awareness for improving holistic well-being in the digital era should be promoted through various platforms.
Topics: Humans; Female; India; Loneliness; Students; Young Adult; COVID-19; Adolescent; Prevalence; Universities; Sleep Quality; Surveys and Questionnaires; Adult; Asthenopia
PubMed: 38934830
DOI: 10.4103/ijph.ijph_1761_22 -
Emerging Microbes & Infections Jun 2024, a group of multi-drug resistant, Gram-positive, aerobic and partially acid-fast bacteria, are emerging causes of bacterial conjunctivitis and keratitis. However, the...
, a group of multi-drug resistant, Gram-positive, aerobic and partially acid-fast bacteria, are emerging causes of bacterial conjunctivitis and keratitis. However, the pathogenesis of keratitis is largely unknown. To address this, we used New Zealand White rabbits to develop the first eye infection model and conducted tests to study the pathogenesis mechanisms of . There is increasing evidence that biofilms play a significant role in ocular infections, leading us to hypothesize that biofilm formation is crucial for effective infection. In order to look for potential candidate genes which are important in biofilm formation and keratitis. We performed genome sequencing of two ocular isolates, -PW1004 and -PW899, to identify potential virulence factors. Through and studies, we characterized their biological roles in mediating keratitis. Our findings confirmed that is an ocular pathogen by fulfilling the Koch's postulates, and using genome sequence data, we identified encoding a mycolyltransferase, as a crucial gene in biofilm formation and causing keratitis in the rabbit model. This is the first report demonstrating the novel role of mycolyltransferase in causing ocular infections. Overall, our findings contribute to a better understanding of pathogenesis and provide a potential target for treatment. Specific inhibitors targeting TmytC could serve as an effective treatment option for infections.
PubMed: 38934251
DOI: 10.1080/22221751.2024.2373317 -
European Journal of Histochemistry : EJH Jun 2024Artificial light can affect eyeball development and increase myopia rate. Matrix metalloproteinase 2 (MMP-2) degrades the extracellular matrix, and induces its...
Effects of artificial light with different spectral compositions on refractive development and matrix metalloproteinase 2 and tissue inhibitor of metalloproteinases 2 expression in the sclerae of juvenile guinea pigs.
Artificial light can affect eyeball development and increase myopia rate. Matrix metalloproteinase 2 (MMP-2) degrades the extracellular matrix, and induces its remodeling, while tissue inhibitor of matrix MMP-2 (TIMP-2) inhibits active MMP-2. The present study aimed to look into how refractive development and the expression of MMP-2 and TIMP-2 in the guinea pigs' remodeled sclerae are affected by artificial light with varying spectral compositions. Three weeks old guinea pigs were randomly assigned to groups exposed to five different types of light: natural light, LED light with a low color temperature, three full spectrum artificial lights, i.e. E light (continuous spectrum in the range of ~390-780 nm), G light (a blue peak at 450 nm and a small valley 480 nm) and F light (continuous spectrum and wavelength of 400 nm below filtered). A-scan ultrasonography was used to measure the axial lengths of their eyes, every two weeks throughout the experiment. Following twelve weeks of exposure to light, the sclerae were observed by optical and transmission electron microscopy. Immunohistochemistry, Western blot and RT-qPCR were used to detect the MMP-2 and TIMP-2 protein and mRNA expression levels in the sclerae. After four, six, eight, ten, and twelve weeks of illumination, the guinea pigs in the LED and G light groups had axial lengths that were considerably longer than the animals in the natural light group while the guinea pigs in the E and F light groups had considerably shorter axial lengths than those in the LED group. Following twelve weeks of exposure to light, the expression of the scleral MMP-2 protein and mRNA were, from low to high, N group, E group, F group, G group, LED group; however, the expression of the scleral TIMP-2 protein and mRNA were, from high to low, N group, E group, F group, G group, LED group. The comparison between groups was statistically significant (p<0.01). Continuous, peaks-free or valleys-free artificial light with full-spectrum preserves remodeling of scleral extracellular matrix in guinea pigs by downregulating MMP-2 and upregulating TIMP-2, controlling eye axis elongation, and inhibiting the onset and progression of myopia.
Topics: Animals; Guinea Pigs; Matrix Metalloproteinase 2; Tissue Inhibitor of Metalloproteinase-2; Sclera; Light; Myopia; Refraction, Ocular
PubMed: 38934084
DOI: 10.4081/ejh.2024.3982 -
Molecular Therapy. Methods & Clinical... Jun 2024Mucolipidosis IV (MLIV) is a rare, autosomal recessive, lysosomal disease characterized by intellectual disability, motor deficits, and progressive vision loss. Using...
Mucolipidosis IV (MLIV) is a rare, autosomal recessive, lysosomal disease characterized by intellectual disability, motor deficits, and progressive vision loss. Using adeno-associated vector 9 (AAV9) and AAV-PHP.B as delivery vectors, we previously demonstrated the feasibility of modifying disease course in a mouse model of MLIV by the human gene transfer. Here, using a primate-enabling capsid AAV.CPP.16 (CPP16), we constructed a new, clinic-oriented gene expression vector and demonstrated its efficacy in the preclinical model of MLIV. Systemic administration of CPP16-MCOLN1 in adult symptomatic mice at a dose of 1e12 vg per mouse resulted in expression in the brain and peripheral tissues, alleviated brain pathology, rescued neuromotor function, and completely prevented paralysis. Notable expression of transcripts was also detected in the retina of the mouse, which had exhibited significant degeneration at the time of the treatment. However, no increase in retinal thickness was observed after gene therapy treatment. Our results suggest a new AAV-based systemic gene replacement therapy for the treatment of MLIV that could be translated into clinical studies.
PubMed: 38934011
DOI: 10.1016/j.omtm.2024.101269 -
Food Chemistry: X Oct 2024In the present study, the comprehensive quality of Congou black tea (CBT) including aroma, taste, and liquid color was investigated by a combination of gas...
In the present study, the comprehensive quality of Congou black tea (CBT) including aroma, taste, and liquid color was investigated by a combination of gas chromatography electronic nose (GC--Nose), electronic tongue (-tongue), and electronic eye (-eye). An excellent discrimination of different quality grades of CBT was accomplished through the fusion of GC--Nose, -tongue, and -eye combined with orthogonal partial least squares discriminant analysis, with parameters of RY = 0.803 and Q = 0.740. Moreover, the quantitative evaluation of CBT quality was successfully achieved by partial least squares regression analysis, with the absolute error within 1.39 point, and the relative error within 1.62%. Additionally, 12 key variables were screened out by stepwise multiple linear regression analysis, which significantly contributed to the comprehensive quality score of CBT. Our results suggest that the fusion of multiple intelligent sensory technologies offers great potential and practicability in the quality evaluation of black tea.
PubMed: 38933990
DOI: 10.1016/j.fochx.2024.101519