Abstract
Retinal neurons process light signals and respond to mechanical signals. mechanosensitive channels (MSCs) have been revealed in all retinal layers in humans, monkeys, mice, rats, porcine, salamanders, goldfish, etc. Some MSCs open in physiological conditions to regulate membrane potential, light responses, and neurotransmitter release, and some MSCs can mediate neurodegenerative effects. Alterations in the intraocular and external pressure critically involve the pathogenesis of glaucoma, traumatic retinal injury (TRI), and other retinal disorders. Our team revealed several MSCs in the outer and inner retinal neurons and first reported the pressure-evoked current and voltage response in salamander photoreceptors and primate bipolar cells. It is still unclear how retinal light pathways deal with endogenous and exogenous mechanical stimulation, and the physiological and pathological significance for retinal neurons to express multiple types of MSCs is not fully understood. This chapter will focus on the variety and functions of MSCs permeable to K+, Na+, and Ca2+, primarily including the big potassium channel (BK), two-pore domain potassium channel TRAAK and TREK, Piezo, epithelial sodium channel (ENaC), transient receptor potential channel vanilloid (TRPV) TRPV1, TRPV2, TRPV4, etc., in retinal photoreceptors, bipolar cells, horizontal cells, amacrine cells, and ganglion cells.