A5049719969- Neural dynamics and brain function
- Photoreceptor and optogenetics research
- Neuroscience and Neural Engineering
- Visual perception and processing mechanisms
- Retinal Development and Disorders
- Neuroscience and Neuropharmacology Research
- Advanced Fluorescence Microscopy Techniques
- Neuroinflammation and Neurodegeneration Mechanisms
- Transcranial Magnetic Stimulation Studies
- Neurological disorders and treatments
- Memory and Neural Mechanisms
- Vestibular and auditory disorders
- Stress Responses and Cortisol
- Nicotinic Acetylcholine Receptors Study
- Functional Brain Connectivity Studies
- Treatment of Major Depression
- Biofield Effects and Biophysics
- Barrier Structure and Function Studies
- Neonatal and fetal brain pathology
- CRISPR and Genetic Engineering
- Olfactory and Sensory Function Studies
- Pharmacological Effects and Toxicity Studies
- EEG and Brain-Computer Interfaces
- Primate Behavior and Ecology
- Epilepsy research and treatment
Bruker (United States)
2023-2024
Inscopix (United States)
2016-2024
Research Network (United States)
2024
Salk Institute for Biological Studies
2006-2023
Palo Alto Institute
2020
Janssen (United States)
2019
Harvard University
2009-2016
University of California, San Diego
2010
Feedback connections are prevalent throughout the cerebral cortex, yet their function remains poorly understood. Previous studies in anesthetized monkeys found that inactivating feedback from extrastriate visual cortex produced effects striate were relatively weak, generally suppressive, largest for stimuli confined to receptive field center, and detectable only at low stimulus contrast. We studied influence of corticocortical alert using cortical cooling reversibly inactivate areas 2 (V2) 3...
Optogenetics combines optics and genetics to control neuronal activity with cell-type specificity millisecond temporal precision. Its use in model organisms such as rodents, Drosophila, Caenorhabditis elegans is now well-established. However, application of this technology nonhuman primates (NHPs) has been slow develop. One key challenge the delivery viruses light brain through thick dura mater NHPs, which can only be penetrated large-diameter devices that damage brain. The opacity NHP...
Normalization has been proposed as a canonical computation that accounts for variety of nonlinear neuronal response properties associated with sensory processing and higher cognitive functions. A key premise normalization is the excitability neuron inversely proportional to overall activity level network. We tested this by optogenetically activating excitatory neurons in alert macaque primary visual cortex measuring changes function stimulation intensity, or without variable-contrast...
Hierarchical organization is a common feature of mammalian neocortex. Neurons that send their axons from lower to higher areas the hierarchy are referred as "feedforward" (FF) neurons, whereas those projecting in opposite direction called "feedback" (FB) neurons. Anatomical, functional, and theoretical studies suggest these different classes projections play fundamentally roles perception. In primates, laminar differences projection patterns often distinguish two streams. rodents, however,...
Microendoscopic calcium imaging with one-photon miniature microscopes enables unprecedented readout of neural circuit dynamics during active behavior in rodents. In this study, we describe successful application technology the rhesus macaque, demonstrating plug-and-play, head-mounted recordings cellular-resolution from large populations neurons simultaneously bilateral dorsal premotor cortices performance a naturalistic motor reach task. Imaging is stable over several months, allowing us to...
Parallel pathways in the primate visual system parse sensory signal into magnocellular (M), parvocellular (P), and koniocellular (K) streams. These remain anatomically separate distinct from their origination different retinal ganglion cell types, through layers of lateral geniculate nucleus, primary cortex (V1), with M pathway terminating primarily layer 4Cα, P 4Cβ, K cytochrome oxidase blobs 2/3. Recent studies indicate that outputs V1 are less compartmental than previously thought, making...
Normalization has been proposed as a canonical computation operating across different brain regions, sensory modalities, and species. It provides good phenomenological description of non-linear response properties in primary visual cortex (V1), including the contrast function surround suppression. Despite its widespread application throughout system, underlying neural mechanisms remain largely unknown. We recently observed that corticocortical feedback contributes to suppression V1, raising...
Here we describe the development and application of miniature integrated microscopes (miniscopes) paired with microendoscopes that allow for visualization manipulation neural circuits in superficial subcortical brain regions freely behaving animals. Over past decade miniscope platform has expanded to include simultaneous optogenetic capabilities, electrically-tunable lenses enable multi-plane imaging, color-corrected optics, an data acquisition streamlines multimodal experiments. Miniscopes...
Deployment of covert attention to a spatial location can cause large decreases in low-frequency correlated variability among neurons macaque area V4 whose receptive-fields lie at the attended location. It has been estimated that this reduction accounts for substantial fraction attention-mediated improvement sensory processing. These estimates depend on assumptions about how population signals are decoded and conclusion impairs perception, is purely hypothetical. Here we test proposal...
Abstract Objective . After decades of study in humans and animal models, there remains a lack consensus regarding how the action electrical stimulation on neuronal non-neuronal elements—e.g. neuropil, cell bodies, glial cells, etc.—leads to therapeutic effects neuromodulation therapies. To further our understanding therapies, is critical need for novel methodological approaches using state-of-the-art neuroscience tools therapy preclinical models disease. Approach In this manuscript we...
Prolonged exposure to abnormally high calcium concentrations is thought be a core mechanism underlying hippocampal damage in epileptic patients; however, no prior study has characterized activity during seizures the live, intact hippocampus. We have directly investigated this possibility by combining whole-brain electroencephalographic (EEG) measurements with microendoscopic imaging of pyramidal cells CA1 region freely behaving mice treated pro-convulsant kainic acid (KA). observed that KA...
The hippocampus, a structure essential for spatial navigation and memory undergoes anatomical functional changes during chronic stress. Here, we investigate the effects of stress on ability place cells to encode neural representation linear track. To model physiological conditions hippocampal function, transgenic mice expressing genetically encoded calcium indicator GCaMP6f in CA1 pyramidal neurons were chronically administered with 40 µg/ml cortisol 8 weeks. Cortisol-treated exhibited...
Optogenetics has become an important tool for perturbing neural circuitry with unparalleled temporal precision and cell-type specificity. However, direct activation of a specific subpopulation neurons can rapidly modulate the activity other within network may lead to unexpected complex downstream effects. Here, we have developed biologically-constrained computational model that exploits these non-intuitive responses in order gain insight into underlying properties network. We apply this data...
SUMMARY The study of motor cortices in non-human primates is relevant to our understanding human control, both healthy conditions and movement disorders. Calcium imaging miniature microscopes allow the multiple genetically identified neurons with excellent spatial resolution. We used this method examine activity patterns projection deep layers supplementary (SMA) primary areas (M1) four rhesus macaques. implanted gradient index lenses expressed GCaMP6f image calcium transients while animals...
Abstract Optical methods for studying the brain offer powerful approaches understanding how neural activity underlies complex behavior. These typically rely on genetically encoded sensors and actuators to monitor control activity. For microendoscopic calcium imaging, injection of a virus followed by implantation lens probe is required express sensor enable optical access target region. This two‐step process poses several challenges, chief among them being risks associated with mistargeting...