March 2021

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Vinken K, Op de Beeck H. Using deep neural networks to evaluate object vision tasks in rats. PLoS Comput Biol 2021;17(3):e1008714.Abstract
In the last two decades rodents have been on the rise as a dominant model for visual neuroscience. This is particularly true for earlier levels of information processing, but a number of studies have suggested that also higher levels of processing such as invariant object recognition occur in rodents. Here we provide a quantitative and comprehensive assessment of this claim by comparing a wide range of rodent behavioral and neural data with convolutional deep neural networks. These networks have been shown to capture hallmark properties of information processing in primates through a succession of convolutional and fully connected layers. We find that performance on rodent object vision tasks can be captured using low to mid-level convolutional layers only, without any convincing evidence for the need of higher layers known to simulate complex object recognition in primates. Our approach also reveals surprising insights on assumptions made before, for example, that the best performing animals would be the ones using the most abstract representations-which we show to likely be incorrect. Our findings suggest a road ahead for further studies aiming at quantifying and establishing the richness of representations underlying information processing in animal models at large.
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Wendt S, Abdullah Z, Barrett S, Daruwalla C, Go JA, Le B, Li E, Livingston C, Miller M, Nakhleh L, Pecha J, Pothula S, Pradhan S, Sathappan V, Shah A, Sonuyi A-M, Ugoh P, Wang Q, Weber N, Succar T, Blieden L, Mortensen P, Elkin Z, Sun G, Lee AG. A virtual COVID-19 ophthalmology rotation. Surv Ophthalmol 2021;66(2):354-361.Abstract
The coronavirus (COVID-19) pandemic temporarily suspended medical student involvement in clinical rotations, resulting in the need to develop virtual clinical experiences. The cancellation of clinical ophthalmology electives and away rotations reduces opportunities for exposure to the field, to network with faculty, conduct research, and prepare for residency applications. We review the literature and discuss the impact and consequences of COVID-19 on undergraduate medical education with an emphasis on ophthalmic undergraduate medical education. We also discuss innovative learning modalities used from medical schools around the world during the COVID-19 pandemic such as virtual didactics, online cases, and telehealth. Finally, we describe a novel, virtual neuro-ophthalmology elective created to educate medical students on neuro-ophthalmology foundational principles, provide research and presentation opportunities, and build relationships with faculty members. These innovative approaches represent a step forward in further improving medical education in ophthalmology during COVID-19 pandemic and beyond.
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Xie L, Yin Y, Benowitz L. Chemokine CCL5 promotes robust optic nerve regeneration and mediates many of the effects of CNTF gene therapy. Proc Natl Acad Sci U S A 2021;118(9)Abstract
Ciliary neurotrophic factor (CNTF) is a leading therapeutic candidate for several ocular diseases and induces optic nerve regeneration in animal models. Paradoxically, however, although CNTF gene therapy promotes extensive regeneration, recombinant CNTF (rCNTF) has little effect. Because intraocular viral vectors induce inflammation, and because CNTF is an immune modulator, we investigated whether CNTF gene therapy acts indirectly through other immune mediators. The beneficial effects of CNTF gene therapy remained unchanged after deleting CNTF receptor alpha (CNTFRα) in retinal ganglion cells (RGCs), the projection neurons of the retina, but were diminished by depleting neutrophils or by genetically suppressing monocyte infiltration. CNTF gene therapy increased expression of C-C motif chemokine ligand 5 (CCL5) in immune cells and retinal glia, and recombinant CCL5 induced extensive axon regeneration. Conversely, CRISPR-mediated knockdown of the cognate receptor (CCR5) in RGCs or treating wild-type mice with a CCR5 antagonist repressed the effects of CNTF gene therapy. Thus, CCL5 is a previously unrecognized, potent activator of optic nerve regeneration and mediates many of the effects of CNTF gene therapy.

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