ARTICLE | doi:10.20944/preprints201904.0107.v2
Subject: Biology And Life Sciences, Neuroscience And Neurology Keywords: evolution; eyes; stress; UV; plasticity
Online: 15 May 2019 (07:47:16 CEST)
Eyes are quintessential complex traits and our understanding of their evolution guides models of trait evolution in general. A long-standing account of eye evolution argues natural selection favors morphological variations that allow increased functionality for sensing light (Darwin 1859; v. Salvini-Plawen and Mayr 1977; Nilsson and Pelger 1994; Nilsson 2013). While certainly true in part, this focus on visual performance does not entirely explain why diffuse photosensitivity persists even after eyes evolve, or why eyes evolved many times, each time using similar building blocks. Here we briefly review a vast literature indicating most genetic components of eyes historically responded to stress caused directly by light, including UV damage of DNA, oxidative stress, and production of aldehydes. We propose light-induced stress had a direct and prominent role in the evolution of eyes by bringing together genes to repair and prevent damage from light-stress, both before and during the evolution of eyes themselves. Stress-repair and stress-prevention genes were perhaps originally deployed as plastic responses to light and/or as beneficial mutations genetically driving expression where light was prominent. These stress-response genes sense, shield, and refract light but only as reactions to ongoing light stress. Once under regulatory-genetic control, they could be expressed before light stress appeared, evolve as a module, and be influenced by natural selection to increase functionality for sensing light, ultimately leading to complex eyes and behaviors. Recognizing the potentially prominent role of stress in eye evolution invites discussions of plasticity and assimilation and provides a hypothesis for why similar genes are repeatedly used in convergent eyes. Broadening the drivers of eye evolution encourages consideration of multi-faceted mechanisms of plasticity/assimilation and mutation/selection for complex novelties and innovations in general.
ARTICLE | doi:10.20944/preprints202109.0346.v1
Subject: Medicine And Pharmacology, Ophthalmology Keywords: goniopuncture; ab interno trabeculectomy; porcine eyes; glaucoma; predictive test
Online: 20 September 2021 (16:34:00 CEST)
Purpose: To investigate trabeculopuncture (TP) for predicting the outcome of ab interno trabeculectomy (AIT). AIT is an effective, low-risk procedure for open angle glaucoma. Despite widespread utilization, it fails in patients with an unidentified distal outflow resistance. Methods: We bisected 81 enucleated porcine eyes and perfused them for 72 hours. They were assigned to two groups: trial (n=42) and control (n=39). Intraocular pressure (IOP) was measured continuously. At 24 hours, four YAG-laser trabeculopunctures on the nasal trabecular meshwork were performed, followed by a 180° AIT at the same site at 48 hours. Eyes were divided into TP and AIT responders and non-responders; the proportion of TP responders between both AIT groups was compared. Results: Both post-TP and post-AIT IOPs were lower than baseline IOP (p=0.015 and p<0.01, respectively). The success rates of TP and AIT were 69% and 85.7%, respectively. The proportion of TP responders among AIT responders was greater than that of AIT non-responders (p<0.01). Sensitivity and specificity values of TP as predictive test for AIT success were 77.7% and 83.3%, respectively. The positive and negative predictive values were 96.6% and 38.5%, respectively. Conclusion: A 10% reduction in IOP after TP can be used as predictor for the success (>20% IOP decrease) of 180° AIT in porcine eyes.
ARTICLE | doi:10.20944/preprints202308.0689.v1
Subject: Engineering, Bioengineering Keywords: Electroencephalogram (EEG); Mobile EEG, Bluetooth; Resting State; Eyes Open/Closed
Online: 8 August 2023 (14:38:10 CEST)
Electroencephalography (EEG) is a crucial tool in cognitive neuroscience, enabling the study of neurophysiological function by measuring the brain's electrical activity. Its applications are included perception, learning, memory, language, decision-making and neural network mapping. Recently, interest has surged in extending EEG measurements to domestic environments. However, the high costs associated with traditional laboratory EEG systems have hindered accessibility for many individuals and researchers in education, research, and medicine. To tackle this, a mobile-EEG device named "DreamMachine” was developed. A more affordable alternative to both lab-based EEG systems and existing mobile-EEG devices. This system boasts 24-channels, 24-bit resolution, up to 6 hours of battery life, portability and a low price. Our open-source and open-hardware approach empowers cognitive neuroscience, especially in education, learning, and research, opening doors to more accessibility. This paper introduces the DreamMachine's design and compares it with the lab-based EEG system "asalabTM" in an eyes-open and eyes-closed experiment. The Alpha band exhibited higher power in the power spectrum during eyes-closed conditions, whereas the eyes-open condition showed increased power specifically within the Delta frequency range. Our analysis confirms that the DreamMachine accurately records brain activity, meeting the necessary standards when compared to the asalabTM system.
ARTICLE | doi:10.20944/preprints202306.1624.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: cell penetrating peptide; bioportide; eyes absent protein; neoblast; planarian; confocal microscopy; stem cell
Online: 22 June 2023 (12:29:16 CEST)
Djeya1 (RKLAFRYRRIKELYNSYR), is a very effective cell penetrating peptide (CPP) which mimics the α5 helix of the highly conserved Eya domain (ED) of eyes absent (Eya) proteins. The objective of this study was to bioengineer analogues of Djeya1 that, following effective translocation into planarian tissues, would reduce the ability of neoblasts (totipotent stem cells) and their progeny to regenerate the anterior pole in decapitated S. mediterranea. As a strategy to increase the propensity for helix formation, molecular bioengineering of Djeya1 was achieved by the mono-substitution of the helicogenic aminoisobutyric acid (Aib) at three species variable sites: 10,13,16. CD analyses indicted that Djeya1 is highly helical and that Aib-substitution had little influence on secondary structure. Aib-substituted Djeya1 analogues are highly efficient CPPs, devoid of influence upon cell viability or proliferation. All three peptides increase the migration of PC-3 cells which express high concentrations of Eya. Two peptides, [Aib13]Djeya1 and [Aib16]Djeya1, are bioportides which delay planarian head regeneration. As neoblast are the only cell population capable of division in planaria, these data indicate that bioportide technologies could be utilised to directly manipulate other stem cells in situ, thus negating any requirement for genetic manipulation.
ARTICLE | doi:10.20944/preprints201901.0320.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Acanthamoeba sp.; eyes; toll-like receptor 2 (TLR2); toll-like receptor 4 (TLR4)
Online: 31 January 2019 (07:00:38 CET)
Toll-like receptors (TLRs) play a key role in the innate immune response to numerous pathogens, including Acanthamoeba sp. The aim of this study was to determine the expression of TLR2 and TLR4 in the eyes of mice following intranasal infection with Acanthamoeba sp. Amoebae used in this study were isolated from the bronchial aspirate of a patient with acute myeloid leukemia (AML) and atypical symptoms of pneumonia. We found statistically significant differences in the expression of TLR2 and TLR4 in the eyes of immunocompetent mice at 8, 16, and 24 days post Acanthamoeba sp. infection (dpi) compared to control. Immunosuppressed mice showed significant differences in the expression of TLR2 at 16 and 24 dpi compared to uninfected animals. Our results indicate that TLR2 and TLR4 are upregulated in the eyes of mice in response to Acanthamoeba sp. We suggest that it is possible for trophozoites to migrate through the optic nerve from the brain to the eyes.
REVIEW | doi:10.20944/preprints202207.0118.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: Eyes diseases; Oxidative damage; Antioxidant compounds; Vitamin A; Vitamin C; Lutein; Curcumin; Quercetin; Coenzyme Q10; PUFAs; BPF; Grape seed
Online: 7 July 2022 (09:04:14 CEST)
Abstract Eye health is crucial and the onset of diseases can reduce vision and affect the quality of life of patients. The main causes of progressive and irreversible vision loss include various pathologies such as cataracts, ocular atrophy, corneal opacity, age-related macular degeneration, uncorrected refractive error, posterior capsular opacification, uveitis, glaucoma, diabetic retinopathy, retinal detachment, undetermined disease and other disorders involving oxidative stress and inflammation. The eyes are constantly exposed to the external environment and, for this reason, must be protected from damage from the outside. Many drugs, including cortisonics and antinflammatory drugs have widely been used to counteract eye disorders. However, recent advances have been obtained via supplementation of patients with natural antioxidants and nutraceuticals. In particular, evidence has been accumulated that polyphenols (mostly deriving from Citrus Bergamia) represent a reliable source of antioxidants able to counteract oxidative stress accompanying early stages of eye diseases. Luteolin, in particular, has been found to protect foto-receptors thereby improving vision in many disease states. Moreover, a consistent anti-inflammatory response was found to occur when curcumin is used alone or in combination with other nutraceuticals. On the other hand, CoQ10 has been demonstrated to produce consistent effect in reducing ocular pressure thereby leding to protection in patients undergoing glaucoma. Finally, both grape seed extract rich in anthocyanosides and polynsatured fatty acids (PUFAs) seem to contribute in the prevention of retinal disorders. Thus, combination of nutraceuticals and anti-oxidants may represent the right solution for a multiaction activity in eye protection to be associated to current drug therapies, and this will be of potential interest in early stages of eye disorders.