A5047156095- Genetics, Aging, and Longevity in Model Organisms
- Circadian rhythm and melatonin
- Spaceflight effects on biology
- Neurobiology and Insect Physiology Research
- Photoreceptor and optogenetics research
- Neuroscience and Neural Engineering
- Insect and Arachnid Ecology and Behavior
- Neural dynamics and brain function
- Olfactory and Sensory Function Studies
- Cephalopods and Marine Biology
- Leech Biology and Applications
- Plant and Biological Electrophysiology Studies
- Agriculture Sustainability and Environmental Impact
- Neural Networks and Applications
- Physiological and biochemical adaptations
- 3D Printing in Biomedical Research
- Planarian Biology and Electrostimulation
- Neuroendocrine regulation and behavior
- Animal Genetics and Reproduction
- Ecosystem dynamics and resilience
- Healthcare and Venom Research
- Ion channel regulation and function
- Cognitive Science and Mapping
- Evolutionary Game Theory and Cooperation
- Dietary Effects on Health
University of Oregon
2012-2023
The University of Tokyo
2009
Howard Hughes Medical Institute
1993-2001
University of California, San Francisco
2001
Australian National University
2001
Electrical Geodesics (United States)
1999
The University of Texas Southwestern Medical Center
1995
Salk Institute for Biological Studies
1989-1993
University of California, San Diego
1989
While isolated motor actions can be correlated with activities of neuronal networks, an unresolved problem is how the brain assembles these into organized behaviors like action sequences. Using brain-wide calcium imaging in Caenorhabditis elegans, we show that a large proportion neurons across share information by engaging coordinated, dynamical network activity. This state evolves on cycle, each segment which recruits different sub-populations and explicitly mapped, single trial basis, to...
To investigate the behavioral mechanism of chemotaxis in Caenorhabditis elegans, we recorded instantaneous position, speed, and turning rate single worms as a function time during gradients attractants ammonium chloride or biotin. Analysis showed that each worm track could be divided into periods smooth swimming (runs) frequent (pirouettes). The initiation pirouettes was correlated with change concentration (dC/dt) but not absolute concentration. Pirouettes were most likely to occur when...
Little is known about the physiology of neurons in Caenorhabditis elegans. Using new techniques for situ patch-clamp recording C. elegans, we analyzed electrical properties an identified sensory neuron (ASER) across four developmental stages and 42 unidentified at one stage. We find that ASER nearly isopotential fails to generate classical Na+ action potentials. Rather, displays a high sensitivity input currents coupled depolarization-dependent reduction may endow with wide dynamic range....
Understanding rhythmic behavior at the developmental and genetic levels has important implications for neurobiology, medicine, evolution, robotics. We studied behavior—larval crawling—in genetically developmentally tractable organism, Drosophila melanogaster . used narrow-diameter channels to constrain simple, crawling. quantified crawling segment, muscle levels. showed that larval is made up of a series periodic strides. Each stride consists two phases. First, while most abdominal segments...
With a nervous system of only 302 neurons, the free-living nematode Caenorhabditis elegans is powerful experimental organism for neurobiology. However, laboratory substrate commonly used in C. research, planar agarose surface, fails to reflect complexity this organism's natural environment, complicates stimulus delivery, and incompatible with high-resolution optophysiology experiments. Here we present new class microfluidic devices neurobiology behavior: agarose-free, micron-scale chambers...
Non-invasive recording in untethered animals is arguably the ultimate step analysis of neuronal function, but such recordings remain elusive. To address this problem, we devised a system that tracks neuron-sized fluorescent targets real time. The can be used to create virtual environments by optogenetic activation sensory neurons, or image activity identified neurons at high magnification. By freely moving C. elegans, tested long-standing hypothesis forward and reverse locomotion are...
This paper describes the fabrication and use of a microfluidic device for performing whole-animal chemical screens using non-invasive electrophysiological readouts neuromuscular function in nematode worm, C. elegans. The consists an array microchannels to which electrodes are attached form recording modules capable detecting electrical activity pharynx, heart-like organ involved feeding. is coupled tree-like arrangement distribution channels that automatically delivers one each module. same...
Random search is a behavioral strategy used by organisms from bacteria to humans locate food that randomly distributed and undetectable at distance. We investigated this behavior in the nematode Caenorhabditis elegans, an organism with small, well-described nervous system. Here we formulate mathematical model of random abstracted C. elegans connectome fit large-scale kinematic analysis submicron resolution. The predicts effects neuronal ablations genetic perturbations, as well unexpected...
We have cloned a Na,K-ATPase alpha-subunit gene from Caenorhabditis elegans and discovered that it is identical to the eat-6, eat-6 mutations cause feeble contractions slow, delayed relaxations of pharyngeal muscle. The resting membrane potential mutant pharynxes consistently depolarized compared wild-type. action potentials are smaller, return slower. To explain these abnormalities, we propose reduction activity in mutants leads ion concentration gradients power changes.
Functional left/right asymmetry ("laterality") is a fundamental feature of many nervous systems, but only very few molecular correlates to functional laterality are known. At least two classes chemosensory neurons in the nematode Caenorhabditis elegans functionally lateralized. The gustatory ASE left (ASEL) and right (ASER) bilaterally symmetric that sense distinct cues express set four known chemoreceptors guanylyl cyclase (gcy) gene family. To examine extent lateralization gcy expression...
Chemotaxis during sinusoidal locomotion in nematodes captures simplified form the general problem of how dynamical interactions between nervous system, body, and environment are exploited generation adaptive behavior. We used an evolutionary algorithm to generate neural networks that exhibit klinotaxis, a common chemotaxis which direction chemical gradient closely follows line steepest ascent. Sensory inputs motor outputs model were constrained match Caenorhabditis elegans klinotaxis...
Familiarity discrimination has a significant impact on the pattern of food intake across species. However, mechanism by which recognition memory controls feeding is unclear. Here, we show that nematode Caenorhabditis elegans forms particular foods after experience and displays behavioral plasticity, increasing response when they subsequently recognize familiar food. We found activates pair ADF chemosensory neurons, increase serotonin release. The released mainly acting humorally directly...
The nematode Caenorhabditis elegans migrates toward a preferred temperature on thermal gradient. A candidate neural network for thermotaxis in C. has been identified, but the behavioral strategy implemented by this is poorly understood. In study, we tested whether migration achieved modulating probability of turning behavior, as chemotaxis. This was done subjecting unrestrained wild-type, cryophilic, or thermophilic worms to rapid spatially uniform steps (3 degrees C), up down from...
This article describes the fabrication and use of microfluidic devices for investigating spatial orientation behaviors in nematode worms (Caenorhabditis elegans). Until now, has been studied freely moving nematodes which frequency nature encounters with gradient are uncontrolled experimental variables. In new devices, is held place by a restraint that aligns longitudinal axis body border between two laminar fluid streams, leaving animal's head tail free to move. The content streams can be...
Habituation is a highly conserved phenomenon that remains poorly understood at the molecular level. Invertebrate model systems, like Caenorhabditis elegans , can be powerful tool for investigating this fundamental process. Here we established high-throughput learning assay used real-time computer vision software behavioral tracking and optogenetics stimulation of C. polymodal nociceptor, ASH. Photoactivation ASH with ChR2 elicited backward locomotion repetitive altered aspects response in...