Characterization Of Somatosensation In The Brainstem And The Development Of A Sensory Neuroprosthesis
Neuroscience and Neurobiology
Innovations in neuroprosthetics have restored sensorimotor function to paralysis patients and amputees. However, to date there is a lack of solutions available to adequately address the needs of spinal cord injury patients (SCI). In this dissertation we develop a novel sensor-brain interface (SBI) that delivers electric microstimulation to the cuneate nucleus (CN) to restore somatosensory feedback in patients with intact limbs. In Chapter II, we develop a fully passive liquid metal antenna using gallium-indium (GaIn) alloy injected in polydimethylsiloxane (PDM) channels to measure forces within the physiological sensitivity of a human fingertip. In Chapter III, we present the first chronic neural interface with the CN in primates to provide access to long-term unit recordings and stimulation. In Chapter IV, we demonstrate that microstimulation to the CN is detectable in a Three Alternative Force Choice Oddity task in awake behaving primates. In Chapter V, we explore the downstream effects of CN stimulation on primary somatosensory cortex, in the context of spontaneous and evoked spindles under sedation. In summary, these findings constitute a proof-of-concept for the sensory half of a bidirectional sensorimotor prosthesis in the CN.