Purpose: The authors investigated whether trigeminal sensitization occurs in response to bright light with the retina disconnected from the rest of the central nervous system by optic nerve section.
Methods: In urethane-anesthetized rats, trigeminal reflex blinks were evoked with air puff stimuli directed at the cornea in darkness and at three different light intensities. After normative data were collected, the optic nerve was lesioned and the rats were retested. In an alert rat, reflex blinks were evoked by stimulation of the supraorbital branch of the trigeminal nerve in the dark and in the light.
Results: A 9.1 × 10(3) μW/cm(2) and a 15.1 × 10(3) μW/cm(2) light significantly enhanced the magnitude of reflex blinks relative to blinks evoked by the same trigeminal stimulus when the rats were in the dark. In addition, rats exhibited a significant increase in spontaneous blinking in the light relative to the blink rate in darkness. After lesioning of the optic nerve, the 15.1 × 10(3) μW/cm(2) light still significantly increased the magnitude of trigeminal reflex blinks.
Conclusions: Bright lights increase trigeminal reflex blink amplitude and the rate of spontaneous blinking in rodents. Light can modify trigeminal activity without involving the central visual system.
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http://dx.doi.org/10.1167/iovs.11-7604 | DOI Listing |
Surg Radiol Anat
January 2025
Department of Ophthalmology & Visual Sciences, University of Adelaide, North Terrace, Adelaide, SA, 5000, Australia.
Purpose: To report the normative dimensions of the frontal nerve (FN) on fat-suppressed suppressed gadolinium (fs-gad) enhanced magnetic resonance imaging (MRI).
Method: A retrospective cohort study of patients who underwent coronal fs-gad T1-weighted MRI. Orbits were excluded if there was unilateral or bilateral pathology of the FN or optic nerve sheath (ONS), incomplete MRI sequences, poor image quality or indiscernible FN on radiological assessment.
J Glaucoma
January 2025
Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI.
Precis: Current optical coherence tomography normative sample data may not represent diverse human optic nerve anatomy to accurately classify all individuals with true glaucomatous optic neuropathy.
Purpose: To compare optic nerve head (ONH) measurements between published values from an optical coherence tomography (OCT) normative database and a more diverse cohort of healthy individuals.
Patients And Methods: ONH parameters from healthy participants of the Michigan Screening and Intervention for Glaucoma and Eye Health through Telemedicine (MI-SIGHT) program and the Topcon Maestro-1 normative cohort were compared.
The visual system of teleost fish grows continuously, which is a useful model for studying regeneration of the central nervous system. Glial cells are key for this process, but their contribution is still not well defined. We followed oligodendrocytes in the visual system of adult zebrafish during regeneration of the optic nerve at 6, 24, and 72 hours post-lesion and at 7 and 14 days post-lesion via the sox10:tagRFP transgenic line and confocal microscopy.
View Article and Find Full Text PDFJ Neuroinflammation
January 2025
Department of Neurology, Division of Neuroimmunology, School of Medicine, Johns Hopkins University, Baltimore, MD, 21287, USA.
Chronic innate immune activation in the central nervous system (CNS) significantly contributes to neurodegeneration in progressive multiple sclerosis (MS). Using multiple experimental autoimmune encephalomyelitis (EAE) models, we discovered that NLRX1 protects neurons in the anterior visual pathway from inflammatory neurodegeneration. We quantified retinal ganglion cell (RGC) density and optic nerve axonal degeneration, gliosis, and T-cell infiltration in Nlrx1 and wild-type (WT) EAE mice and found increased RGC loss and axonal injury in Nlrx1 mice compared to WT mice in both active immunization EAE and spontaneous opticospinal encephalomyelitis (OSE) models.
View Article and Find Full Text PDFJ Glaucoma
January 2025
Department of Ophthalmology, Hospital Clínico San Carlos, Instituto de Investigación Sanitaria Hospital Clínico San Carlos (IdISSC), Universidad Complutense. Madrid, Spain.
Prcis: The discriminant function of glaucoma, obtained by the Laguna ONhE colorimetric program, significantly correlates with the BMO-MRW. Furthermore, the diagnostic capacity was inferior to other structural tests in POAG patients.
Purpose: To evaluate the diagnostic capability for glaucoma and the correlation between peripapillary and macular parameters using spectral domain optical coherence tomography (SD-OCT) and optic nerve head hemoglobin (OHN Hb) levels assessed by the Laguna ONhE® software using colorimetric analysis.
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