A5082805309- Neural dynamics and brain function
- Neuroscience and Neuropharmacology Research
- Neuroscience and Neural Engineering
- Memory and Neural Mechanisms
- Photoreceptor and optogenetics research
- Zebrafish Biomedical Research Applications
- Sleep and Wakefulness Research
- Neurobiology and Insect Physiology Research
- Functional Brain Connectivity Studies
- Receptor Mechanisms and Signaling
- Neurotransmitter Receptor Influence on Behavior
- Neuroscience of respiration and sleep
- Visual perception and processing mechanisms
- Action Observation and Synchronization
- Neurological disorders and treatments
- EEG and Brain-Computer Interfaces
- Olfactory and Sensory Function Studies
- Motor Control and Adaptation
- Advanced Chemical Sensor Technologies
- Neuroinflammation and Neurodegeneration Mechanisms
- Vestibular and auditory disorders
- Retinal Development and Disorders
- Neuroendocrine regulation and behavior
- Bat Biology and Ecology Studies
- Adipose Tissue and Metabolism
Humboldt-Universität zu Berlin
2015-2025
University of Sussex
2023-2024
Charité - Universitätsmedizin Berlin
2016-2023
Yale University
2007-2015
Salk Institute for Biological Studies
2007
Vanderbilt University
1997-2006
The University of Texas at San Antonio
2002-2004
John F. Kennedy Center for the Performing Arts
1997
University of Michigan
1989-1991
The responsiveness of cortical neurons is strongly and rapidly influenced by changes in the level local network activity. In rodent somatosensory cortex, increases activity increase neuronal to intracellular injection brief conductance stimuli but paradoxically decrease whisker deflections. However, stimulation frequently evokes long-lasting circuit ability successfully evoke prolonged associated with both an amount evoked a stimulus action potential stimulation. addition, presented during...
Marking functionally distinct neuronal ensembles with high spatiotemporal resolution is a key challenge in systems neuroscience. We recently introduced CaMPARI, an engineered fluorescent protein whose green-to-red photoconversion depends on simultaneous light exposure and elevated calcium, which enabled marking active populations single-cell subsecond resolution. However, CaMPARI (CaMPARI1) has several drawbacks, including background low slow kinetics reduced fluorescence after chemical...
Changes in spontaneous activity within the cortex recognized by subthreshold fluctuations of membrane potential cortical neurons modified response to sensory stimuli. Sensory stimuli occurring hyperpolarized "down" state evoked a larger depolarization and were more effective evoking action potentials than depolarized "up" state. Direct electrical stimulation thalamus showed same dependence on cell's at time stimulus, ruling out strictly thalamic mechanism. Stimuli triggering down even during...
Activity in neocortex is often characterized by synchronized oscillations of neurons and networks, resulting the generation a local field potential (LFP) electroencephalogram. Do neuronal networks cerebellum also generate are they under influence those neocortex? Here we show that, absence any overt external stimulus, cerebellar cortex generates slow oscillation that correlated with neocortex. Disruption neocortical abolishes oscillation, whereas blocking activity has no effect on We provide...
Sniffing, a high-frequency, highly rhythmic inhalation and exhalation of air through the nose, plays an important role in rodent olfaction. Similarly, whisking, active movement whiskers, tactile sensation. Rodents whisk sniff during exploratory behavior to sample odorants surfaces. Whisking is thought be coordinated with sniffing normal respiratory behavior, but precise temporal relationships between these movements are not known. Here, using direct measurements whisking movements, we...
Respiration produces rhythmic activity in the entire olfactory system, driving neurons epithelium, bulb (OB), and cortex. The nature of this is believed to be a critical component sensory processing. OB projection neurons, mitral tufted cells exhibit both spiking subthreshold membrane potential oscillations rhythmically coupled respiration. However, network synaptic mechanisms that produce respiration-coupled activity, effects respiration on lateral inhibition, major processing circuits, are...
Layer 6b (L6b), the deepest neocortical layer, projects to cortical targets and higher-order thalamus is only layer responsive wake-promoting neuropeptide orexin/hypocretin. These characteristics suggest that L6b can strongly modulate brain state, but projections their influence remain unknown. Here, we examine inputs ex vivo in mouse primary somatosensory cortex with rabies-based retrograde tracing channelrhodopsin-assisted circuit mapping slices. We find receives its strongest excitatory...
Sachdev, Robert N. S., Shao-Ming Lu, Ron G. Wiley, and Ford F. Ebner. Role of the basal forebrain cholinergic projection in somatosensory cortical plasticity. J. Neurophysiol. 79: 3216–3228, 1998. Trimming all but two whiskers adult rats produces a predictable change cell-evoked responses characterized by increased responsiveness to intact decreased trimmed whiskers. This type synaptic plasticity rat somatic sensory cortex, called “whisker pairing plasticity,” first appears cells above below...
The current view of whisker movement is that ∼25 whiskers on each side the face move in synchrony. To determine whether are constrained to together, we trained rats use two same simple behavioral tasks and videotaped during task. Here report adjacent usually synchronous but can diverge: 1) distance between vary dramatically movement; 2) one while second remains stationary; 3) simultaneously opposite directions; 4) be maintained contact with an object other retracted protracted. frequency...
During natural vision the entire retina is stimulated. Likewise, during tactile behaviors, spatially extensive regions of somatosensory surface are co-activated. The large spatial extent naturalistic stimulation means that surround suppression, a phenomenon whose neural mechanisms remain matter debate, must arise behavior. To identify common motifs might instantiate suppression across modalities, we review models and compare evidence supporting competing ideas has either cortical or...
A widely accepted view is that wakefulness a state in which the entire cortical mantle persistently activated, and therefore desynchronized. Consequently, EEG dominated by low-amplitude, high-frequency fluctuations. This currently under revision because 1–4 Hz delta rhythm often evident during “quiet” rodents nonhuman primates. Here we used intracranial recordings to assess occurrence of 18 awake human beings. Our reveal rhythmic at 10% all recording sites. Delta could be observed single...
Prompt execution of planned motor action is essential for survival. The interactions between frontal cortical circuits and the basal ganglia are central to goal-oriented selection initiation.1Graybiel A.M. ganglia.Curr. Biol. 2000; 10: R509-R511Abstract Full Text PDF PubMed Scopus (391) Google Scholar, 2Hikosaka O. Nakamura K. Sakai Nakahara H. Central mechanisms skill learning.Curr. Opin. Neurobiol. 2002; 12: 217-222Crossref (664) 3Middleton F.A. Strick P.L. Basal cerebellar loops:...
Flexible learning relies on integrating sensory and contextual information to adjust behavioral output in different environments. The anterolateral motor cortex (ALM) is a frontal area critical for action selection rodents. Here we show that inputs decision-making converge the apical tuft dendrites of L5b pyramidal neurons ALM. We therefore investigated role these rule-switching paradigm. Activation dendrite-inhibiting layer 1 interneurons impaired relearning, without affecting previously...
Abstract Neocortical layer 1 has been proposed to be at the center for top-down and bottom-up integration. It is a locus interactions between long-range inputs, interneurons, apical tuft dendrites of pyramidal neurons. While input studied intensively, level effect this still not completely characterized. Here we examined mouse somatosensory cortex with retrograde tracing optogenetics. Our assays reveal that local predominantly from layers 2/3 5 neurons subtypes 6b project different...
Electromyographic recordings from the mystacial pad of rats were used to assess effect unilateral vibrissa contact on bilateral movement vibrissae. A first group animals was trained whisk freely in air and served establish baseline variability symmetry. We observed that electromyogram (EMG) activity across two pads rhythmic synchronous within 2 ms a whisk-by-whisk basis; this value is small comparison with ˜50 required for protraction during cycle. second use their vibrissae sensor located...
Brain signaling requires energy. The cost of maintaining and supporting energetically demanding neurons is the key constraint on brain size. dramatic increase in size among mammals birds cannot be understood without solving this conundrum: larger brains, with more neurons, consume energy.Here we examined intrinsic relationships between metabolism, body-brain ratios neuronal densities both endothermic ectothermic animals. We formulated a general model to elucidate factors that correlate...
The genetically encoded fluorescent calcium integrator calcium-modulated photoactivatable ratiobetric (CaMPARI) reports influx induced by synaptic and neural activity. Its fluorescence is converted from green to red in the presence of violet light calcium. rate conversion - sensitivity activity tunable depends on intensity light. Synaptic action potentials can independently initiate significant CaMPARI conversion. level subthreshold inputs correlated strength input, enabling optical readout...
Abstract Here, we describe an automated optical method for tracking animal behavior in both head-fixed and freely moving animals, real time offline. It takes advantage of off-the-shelf camera system, the Pixy camera, designed as a fast vision sensor robotics that uses color-based filtering algorithm at 50 Hz to track objects. Using customized software, demonstrate versatility our approach by first rostro-caudal motion individual adjacent row (D1, D2) or arc whiskers (β, γ), single whisker...