Wednesday, May 21, 2025
5/21/2025
Longitudinal neuronal and behavioral responses to microstimulation of LGN by ultraflexible electrodes - Project summary Approximately 40 million people across the world suffer from blindness, a condition severely impacting their autonomy and quality of life. Restoration of visual function in these blind individuals is an important scientific goal with large societal benefits. Current visual prosthetic devices interface with the visual pathways at the retina or the visual cortex. Retinal prostheses are relatively safe to implant but are not applicable for most blind patients who have severe eye damage causing a disconnection with the brain. Cortical prostheses could open treatments to a much wider range of diseases and patients, but making such devices applicable to human patients faces significant challenges, particularly in the lack of sufficient visual field coverage and lack of tissue compatibility for long-term implantation. To overcome these limitations, this bioengineering research grant proposes a unique approach for visual prostheses, using large-scale, tissue-integrated, ultraflexible electrodes to interface with the lateral geniculus nucleus (LGN), the relay station between the retina and the visual cortex. The objective of this project is to establish the feasibility and acquire the key knowledge to build a lasting LGN visual prosthesis with an unprecedented visual coverage able to elicit pattern perception. To achieve this goal, we will use NanoElectronic Threads (NETs), currently the thinnest, most flexible, least tissue-invasive indwelling electrodes for stable, long-lasting microstimulation in the LGN. We will implant a large array of 500 – 1000 channels in the relatively small volume of LGN in NHP to attain sufficient coverage of the visual field and resolution of artificial vision. Aim 1 will examine the perceptual properties of phosphenes elicited by microstimulation of LGN in NHP, for which we will determine the receptive field and visual field coverage and establish shape perception. Aim 2 will elucidate neural responses and downstream signaling of LGN stimulation in mice. We will determine the longitudinal stability of LGN and V1 activation as well as the stability of RFs of stimulated LGN neurons in both normal seeing and blind animals. Aim 3 will optimize and determine the long-term stability of phosphene detection in NHP. We will evaluate and optimize charge injection capacity of NETs in vitro and determine the stability of perception in NHP for two years. The project will drive both scientific advancements in visual system neuroscience and technological innovation of flexible prostheses engineering, paving the way for a revolutionary, high-resolution visual prosthesis that can offer unprecedented levels of sight restoration and transform the lives of millions of people suffering from blindness.
HHS’ Tracking Accountability in Government Grants System (TAGGS) website provides access to detailed descriptions of grants, loans, aggregated direct payments and other types of financial assistance awarded by the HHS Operating Divisions (OPDIVs) and the Office of the Secretary Staff Divisions (STAFFDIVs).