Defocused Images Change Multineuronal Firing Patterns in the Mouse Retina

Abstract

Myopia is a major public health problem, affecting one third of the population over 12 years old in the United States and more than 80% of people in Hong Kong. Myopia is attributable to elongation of the eyeball in response to defocused images that alter eye growth and refraction. It is known that the retina can sense the focus of an image, but the effects of defocused images on signaling of population of retinal ganglion cells (RGCs) that account either for emmetropization or refractive errors has still to be elucidated. Thorough knowledge of the underlying mechanisms could provide insight to understanding myopia. In this study, we found that focused and defocused images can change both excitatory and inhibitory conductance of ON alpha, OFF alpha and ON-OFF retinal ganglion cells in the mouse retina. The firing patterns of population of RGCs vary under the different powers of defocused images and can be affected by dopamine receptor agonists/antagonists' application. OFF-delayed RGCs or displaced amacrine cells (dACs) with time latency of more than 0.3 s had synchrony firing with other RGCs and/or dACs. These spatial synchrony firing patterns between OFF-delayed cell and other RGCs/dACs were significantly changed by defocused image, which may relate to edge detection. The results suggested that defocused images induced changes in the multineuronal firing patterns and whole cell conductance in the mouse retina. The multineuronal firing patterns can be affected by dopamine receptors' agonists and antagonists. Synchronous firing of OFF-delayed cells is possibly related to edge detection, and understanding of this process may reveal a potential therapeutic target for myopia patients.

Increased Connexin36 Phosphorylation in AII Amacrine Cell Coupling of the Mouse Myopic Retina

“…Recent research has shown ON activity tends to inhibit myopia, and OFF activity tends to inhibit development of hyperopia in mice (Chakraborty et al, 2015) and chicken (Crewther and Crewther, 2003). Our research has also shown that defocused images change the signaling of some ON and OFF α RGCs and ON-OFF RGCs in the mouse retina (Pan, 2019;Banerjee et al, 2020). From its already recognized biological effects, retinal signaling is a strong candidate for mediating the retina-to-sclera signaling pathway in refractive development and may be involved in the development of human myopia.…”

Defocus Incorporated Multiple Segments Spectacle Lenses Changed the Relative Peripheral Refraction: A 2-Year Randomized Clinical Trial

“…Recently, Pan 43 reported that the signaling of ON-OFF retinal ganglion cells (RGCs) in the mouse retina could be changed by a defocused image, and showed different responses to varied powers of defocus image. 44 We assumed the signaling of RGCs might be altered by the defocus power in the DIMS lens and resulting in a uniform and symmetrical pattern change in the peripheral refraction. Nevertheless, further animal studies will be needed.…”

Effects of screen-based retinal light stimulation measured with a novel contrast sensitivity test

“…Along this line, animal models that were exposed to light of different wavelengths indicated inconclusive results regarding axial elongation. In mice [11,[15][16][17][18][19], chicks [20][21][22][23][24] and fish [25,26] short-wavelength light promote hyperopic shifts, whereas the eyes of rhesus monkeys [27][28][29][30] and guinea pigs [11,[30][31][32][33][34][35] reacted oppositely. Hypotheses on light-induced shifts in refractive error are commonly based on the longitudinal chromatic aberration [36], creating myopic and hyperopic defocus as growth stimulus for the retina [10,12,37].…”