PROJECT SUMMARY/ABSTRACT Mechanosensitive ion channels were shown to drive mechanically induced inflammatory signaling in the central and peripheral nervous systems and to exacerbate pathology in neuropathies, skeletal diseases, traumatic brain injury and other neurodegenerative conditions. Suppressing their activation with gene knockdown and pharmacology reduces inflammatory neuropathy and neuronal injury yet despite this knowledge their role in neuroinflammation is little understood, and their contribution to pressure-associated retinal diseases such as glaucoma has never been investigated. The goal of the proposed project is to resolve this major gap in knowledge by defining the molecular targets of intraocular pressure in the principal retinal macroglia, the Müller cell, and establish the significance of Müller pressure sensing for neuroinflammation, glia-neuronal interactions and neurodegeneration. The overall hypothesis of this project is that mechanosensitive TRP and piezo channels trigger and drive inflammatory activation in the presence of mechanical stressors such as intraocular pressure and strain and that this process can be targeted by pharmacological/genetic methods to alleviate neuronal injury. We will address this hypothesis in two specific aims. Aim 1 focuses on the characterization of properties of mechanoactivated ion channels that mediate pressure signaling in Müller cells. In Aim 2 we propose to take advantage of new conditional mouse models to elucidate how pressure elevations induce reactive gliosis, the role of mechanotransduction in glia-glia and glia-neuronal circuits, and significance of this mechanism for ganglion cell stress and survival. Successful completion of these multidisciplinary, thematically related yet independent approaches may help define new diagnostic and treatment strategies in hypertensive glaucoma.