Oct 31, 2019
Room 218, Whitaker Hall
Qi Wang, PhD
Department of Biomedical Engineering
Reading and Writing the Neural Code: Initial Steps Towards Restoring and Enhancing Sensory Functions Using Brain-Machine Interfaces
Sensory signals, such as light, sound, and skin deformation, are transduced to neuronal electrical impulses, or spikes, at the periphery. These spikes are subsequently transmitted to the neocortex through the sensory pathways, ultimately forming perception of the sensory world. Information processing along these pathways is heavily dependent upon both the external sensory environment and internal brain state. Therefore, to restore and/or enhance brain sensory functions using brain-machine interfaces, we will need to understand not only how the information is dynamically encoded by populations of neurons, but also how to devise strategies to optimize brain state. My talk will first use sensory adaptation as an example to demonstrate that the sensory pathway adaptively changes the neural code based on the properties of sensory stimuli. Sensory adaptation strongly shaped thalamic synchrony and dictated the window of integration of the recipient cortical targets, effectively switching the nature of what information about the outside world is being conveyed to cortex. Second, I will discuss how to enhance sensory processing and perception through control of the activity of the locus coeruleus – norepinephrine (LC-NE) system, a major neuromodulatory system. Our data demonstrated that LC activation increased the feature sensitivity and thus information transmission for thalamic relay neurons while decreasing their firing rate. Moreover, LC-NE optimization of thalamic sensory processing is also critical to perception as LC activation increased the perceptual sensitivity of animals performing tactile discrimination tasks, and this improvement was blocked when NE effects in the thalamus were pharmacologically precluded. Finally, I will talk about our ongoing work towards using non-invasive vagus nerve stimulation to substitute direct LC stimulation to enhance information processing in the brain. Taken together, an understanding of how to read and write the neural code is not only essential to the development of brain-machine interface technologies for restoring and enhancing sensory perception, but also will provide insights into diagnosis and treatment of neurological/neuropsychiatric disorders involving aberrant information processing.
Organizer / Host: Barani Raman