A5026654708- Neural dynamics and brain function
- Visual perception and processing mechanisms
- Neuroscience and Neuropharmacology Research
- Neurobiology and Insect Physiology Research
- Photoreceptor and optogenetics research
- Neuroscience and Neural Engineering
- Memory and Neural Mechanisms
- Retinal Development and Disorders
- EEG and Brain-Computer Interfaces
- Olfactory and Sensory Function Studies
- Neural and Behavioral Psychology Studies
- Neuroscience, Education and Cognitive Function
- Neural Networks and Applications
- Receptor Mechanisms and Signaling
- Functional Brain Connectivity Studies
- Cell Image Analysis Techniques
- Color Science and Applications
- Multisensory perception and integration
- Advanced Fluorescence Microscopy Techniques
- Advanced Memory and Neural Computing
- Molecular Communication and Nanonetworks
- Visual and Cognitive Learning Processes
- Cognitive Science and Education Research
- Color perception and design
- Optical Imaging and Spectroscopy Techniques
University College London
2016-2025
Institute of Ophthalmology
2012-2025
UniNettuno University
2025
ORCID
2022
University College Hospital
2012-2014
UCL Australia
2014
Smith-Kettlewell Eye Research Institute
2003-2012
Imperial College London
2012
New York University
1994-2007
ETH Zurich
2002-2007
Neuron activity across the brain How is it that groups of neurons dispersed through interact to generate complex behaviors? Three papers in this issue present brain-scale studies neuronal and dynamics (see Perspective by Huk Hart). Allen et al. found thirsty mice, there widespread neural related stimuli elicit licking drinking. Individual encoded task-specific responses, but every area contained with different types response. Optogenetic stimulation thirst-sensing one reinstated drinking...
Abstract Two-photon microscopy of calcium-dependent sensors has enabled unprecedented recordings from vast populations neurons. While the and microscopes have matured over several generations development, computational methods to process resulting movies remain inefficient can give results that are hard interpret. Here we introduce Suite2p: a fast, accurate complete pipeline registers raw movies, detects active cells, extracts their calcium traces infers spike times. Suite2p runs on standard...
Simple cells in the primary visual cortex often appear to compute a weighted sum of light intensity distribution stimuli that fall on their receptive fields. A linear model these has advantage simplicity and captures number basic aspects cell function. It, however, fails account for important response nonlinearities, such as decrease gain latency observed at high contrasts effects masking by fail elicit responses when presented alone. To nonlinearities we have proposed normalization model,...
Measuring the dynamics of neural processing across time scales requires following spiking thousands individual neurons over milliseconds and months. To address this need, we introduce Neuropixels 2.0 probe together with newly designed analysis algorithms. The has more than 5000 sites is miniaturized to facilitate chronic implants in small mammals recording during unrestrained behavior. High-quality recordings long were reliably obtained mice rats six laboratories. Improved site density...
Abstract Advances in silicon probe technology mean that vivo electrophysiological recordings from hundreds of channels will soon become commonplace. To interpret these we need fast, scalable and accurate methods for spike sorting, whose output requires minimal time manual curation. Here introduce Kilosort, a sorting framework meets criteria, show it allows rapid large-scale data. Kilosort models the recorded voltage as sum template waveforms triggered on times, allowing overlapping spikes to...
Recordings from monkey primary visual cortex (V1) were used to test a model for the visually driven responses of simple cells. According model, cells compute linear sum lateral geniculate nucleus (LGN) neurons. In addition, each cell's response is divided by pooled activity large number other The cell membrane performs both operations; synaptic currents are summed and then total conductance. Current conductance decoupled (by complementary arrangement excitation inhibition) so that current...
The input conductance of cells in the cat primary visual cortex (V1) has been shown recently to grow substantially during stimulation. Because increasing can have a divisive effect on synaptic input, theoretical proposals ascribed it specific functions. According veto model, increases would serve sharpen orientation tuning by most at off-optimal orientations. normalization control cell's gain, being independent stimulus and growing with contrast. We set out test these determine properties...
We have investigated the relationship between membrane potential and firing rate in cat visual cortex found that spike threshold contributes substantially to sharpness of orientation tuning. The half-width at half-height tuning responses was 23 +/- 8 degrees, compared with 38 15 degrees for responses. Direction selectivity also greater (direction index, 0.61 0.35) than (0.28 0.21). Threshold increased distinction simple complex cells, which is commonly based on linearity drifting sinusoidal...
The firing rate responses of neurons in the primary visual cortex grow with stimulus contrast, variation luminance an image relative to mean luminance. These responses, however, are reduced after a cell is exposed for prolonged periods high-contrast stimuli. This phenomenon, known as contrast adaptation, occurs and not present at earlier stages processing. To investigate cellular mechanisms underlying cortical intracellular recordings were performed cats, effects stimulation studied....