A5045444914- Neural dynamics and brain function
- Neuroscience and Neural Engineering
- Visual perception and processing mechanisms
- Photoreceptor and optogenetics research
- Neuroscience and Neuropharmacology Research
- EEG and Brain-Computer Interfaces
- Neurobiology and Insect Physiology Research
- Functional Brain Connectivity Studies
- Spaceflight effects on biology
- Memory and Neural Mechanisms
- Advanced Memory and Neural Computing
- Electrochemical Analysis and Applications
- Heart Rate Variability and Autonomic Control
- Neural Networks and Applications
- Tactile and Sensory Interactions
- Olfactory and Sensory Function Studies
- stochastic dynamics and bifurcation
- Retinal Development and Disorders
- Neural and Behavioral Psychology Studies
- Advanced Sensor and Energy Harvesting Materials
- Control Systems and Identification
- Visual Attention and Saliency Detection
- Image Processing Techniques and Applications
- Advanced Vision and Imaging
- Neurological disorders and treatments
Georgia Institute of Technology
2016-2025
The Wallace H. Coulter Department of Biomedical Engineering
2016-2025
Emory University
2008-2024
Emory and Henry College
2022-2024
Harvard University
2000-2008
Massachusetts Institute of Technology
2003-2008
Harvard University Press
2007
Los Angeles Pierce College
2004-2006
Harvard–MIT Division of Health Sciences and Technology
2006
University of California, Berkeley
1997-2002
The hippocampus is essential for learning complex spatial relationships, but little known about how hippocampal neural activity changes as animals learn a novel environment. We studied the formation of new place representations in rats by examining place-specific firing neurons CA1 region and relationship between these behavioral change across multiple days exposure to places. found that many showed very rapid on first day place, including cases which previously silent neuron developed field...
A major challenge in studying sensory processing is to understand the meaning of neural messages encoded spiking activity neurons. From recorded responses a circuit, what information can we extract about outside world? Here used linear decoding technique reconstruct spatiotemporal visual inputs from ensemble lateral geniculate nucleus (LGN) cat. 177 cells, have reconstructed natural scenes with recognizable moving objects. The quality reconstruction depends on number cells. For each point...
The role of the lateral geniculate nucleus (LGN) thalamus in visual encoding remains an open question. Here, we characterize function tonic and burst spikes cat LGN X-cells signaling features natural stimuli. A significant increase bursting was observed during stimulation (relative to white noise stimulation) linked strong correlation structure scene movies. Burst responses were triggered by specific stimulus events consisting a prolonged inhibitory stimulus, followed excitatory such as...
Optogenetic techniques enable precise excitation and inhibition of firing in specified neuronal populations artifact-free recording activity. Several studies have suggested that optical stimulation provides the precision dynamic range requisite for closed-loop control, but no approach yet permits feedback control firing. Here we present ‘optoclamp’, a technology continuous, real-time adjustments bidirectional order to lock spiking activity at targets over timescales ranging from seconds...
Soft and magnetic resonance imaging (MRI) compatible neural electrodes enable stable chronic electrophysiological measurements anatomical or functional MRI studies of the entire brain without electrode interference with images. These properties are important for many studies, ranging from a fundamental neurophysiological study signals to neuromodulatory effect investigation therapeutic deep stimulation. Here we develop soft using carbon nanotube (CNT) fibers diameter 20 μm down 5 μm. The CNT...
Cortical compression can be a significant problem in many types of brain injuries, such as trauma, localized edema, hematoma, focal cerebral ischemia, or tumors. Mechanical and cellular alterations result global changes excitation inhibition on the neuronal network level even absence histologically cell injury, often manifesting clinically seizures. Despite importance prevalence this problem, however, precise electrophysiological effects injury have not been well characterized. In study,...
Lateralization is a hallmark of somatosensory processing in the mammalian brain. However, addition to their contralateral representation, unilateral tactile stimuli also modulate neuronal activity cortices ipsilateral hemisphere. The cellular organization and functional role these stimulus responses awake cortices, especially regarding coding, are unknown. Here, we targeted silicon probe recordings vibrissa region primary (S1) secondary (S2) cortex head-fixed mice either sex while delivering...
The feedback projections from cortical layer 6 (L6CT) to the sensory thalamus have long been implicated in playing a primary role gating signaling but remain poorly understood. To causally elucidate full range of effects these projections, we targeted silicon probe recordings whisker thalamocortical circuit awake mice selectively expressing Channelrhodopsin-2 L6CT neurons. Through optogenetic manipulation neurons, multi-site electrophysiological recordings, and modeling circuitry, establish...
In the lateral geniculate nucleus (LGN) of thalamus, visual stimulation produces two distinct types responses known as tonic and burst. Due to dynamics T-type Ca(2+) channels involved in burst generation, type response evoked by a particular stimulus depends on resting membrane potential, which is controlled network modulatory connections from other brain areas. this study, we use simulated natural scene movies describe how stimulus-driven changes LGN potential interact determine luminance...
Thalamic neurons respond to visual scenes by generating synchronous spike trains on the timescale of 10–20 ms that are very effective at driving cortical targets. Here we demonstrate this activity contains unexpectedly rich information about fundamental properties stimuli. We report occurrence firing cat thalamic cells with highly overlapping receptive fields is strongly sensitive orientation and direction motion stimulus. show stimulus selectivity robust, remaining relatively unchanged...
It has been posited that the regulation of burst/tonic firing in thalamus could function as a mechanism for controlling not only how much but what kind information is conveyed to downstream cortical targets. Yet this gating adaptively modulated on fast timescales by ongoing sensory inputs rich environments remains unknown. Using single-unit recordings rat vibrissa (VPm), we found degree bottom-up adaptation thalamic well synchronization bursting across population along continuum which...
Controlling neural activity enables the possibility of manipulating sensory perception, cognitive processes, and body movement, in addition to providing a powerful framework for functionally disentangling circuits that underlie these complex phenomena. Over last decade, optogenetic stimulation has become an increasingly important tool understanding circuit function, owing ability target specific cell types bidirectionally modulate activity. To date, most been provided open-loop or on/off...
Rapid sensory adaptation is observed across all systems, and strongly shapes percepts in complex environments. Yet despite its ubiquity likely necessity for survival, the mechanistic basis poorly understood. A wide range of primarily vitro anesthetized studies have demonstrated emergence at level primary cortex, with only modest signatures earlier stages processing. The nature rapid how it representations during wakefulness, thus potential role perceptual adaptation, underexplored, as are...