A5017035439- Adenosine and Purinergic Signaling
- Neuroscience and Neuropharmacology Research
- Ion channel regulation and function
- Neurobiology and Insect Physiology Research
- Neuroscience and Neural Engineering
- Neuroscience of respiration and sleep
- Neuroendocrine regulation and behavior
- Neurogenesis and neuroplasticity mechanisms
- Receptor Mechanisms and Signaling
- Photoreceptor and optogenetics research
- Zebrafish Biomedical Research Applications
- Nicotinic Acetylcholine Receptors Study
- Physiological and biochemical adaptations
- Nerve injury and regeneration
- Crustacean biology and ecology
- Cellular transport and secretion
- Planarian Biology and Electrostimulation
- Neural dynamics and brain function
- Hearing Loss and Rehabilitation
- Retinal Development and Disorders
- Pluripotent Stem Cells Research
- Hearing, Cochlea, Tinnitus, Genetics
- Vestibular and auditory disorders
- Bipolar Disorder and Treatment
- Calcium signaling and nucleotide metabolism
University of Michigan
2007-2022
Institut thématique Génétique, génomique et bioinformatique
1997-2012
Michigan United
2012
University of Washington
2000
United States Naval Academy
1998
Salk Institute for Biological Studies
1991-1992
Washington University in St. Louis
1981-1984
Stanford University
1982
Wesleyan University
1976
A prerequisite for many studies of neurons in culture is a means determining their original identity. We needed such technique to study the interactions vitro between class spinal cord neurons, sympathetic preganglionic and normal target, from chain. Here, we describe how use two highly fluorescent carbocyanine dyes, which differ color but are otherwise similar, identify culture. The long carbon chain dyes lipid-soluble so become incorporated into plasma membrane. Neurons can be labeled...
The neurotransmitter glutamate mediates excitatory synaptic transmission throughout the brain. A family of genes encoding subunits non- N -methyl-D-aspartate (non-NMDA) type receptor has been cloned. Some combinations these assemble into receptors with a substantial permeability to calcium, whereas others do not. To investigate structural features that control ion permeation through ligand-gated channels, mutant single-amino acid changes were constructed. Mutation certain amino results in...
Basic helix-loop-helix (bHLH) transcription factors are known to function during mammalian neurogenesis. Here we show that transient transfection of vectors expressing neuroD2, MASH1, ngn1 or related neural bHLH proteins, with their putative dimerization partner E12, can convert mouse P19 embryonal carcinoma cells into differentiated neurons. Transfected express numerous neuron-specific adopt a neuronal morphology and electrically excitable. Thus, the expression proteins is sufficient confer...
Axonal degeneration is a hallmark of many neuropathies, neurodegenerative diseases, and injuries. Here, using Drosophila injury model, we have identified highly conserved E3 ubiquitin ligase, Highwire (Hiw), as an important regulator axonal synaptic degeneration. Mutations in hiw strongly inhibit Wallerian multiple neuron types developmental stages. This new phenotype mediated by downstream target Hiw: the NAD+ biosynthetic enzyme nicotinamide mononucleotide adenyltransferase (Nmnat), which...
A single site in recombinant glutamate receptor channels of the GluR1-GluR4 family has been previously identified as a key regulator ion permeation. The natural amino acid at this position (arginine GluR2 but glutamine GluR1, GluR3, and GluR4) determines both ability to pass outward current divalent cation permeability kainate-activated channels. By mutagenesis GluR6, we demonstrated that same also controls another non-NMDA family. Additional mutations near GluR3 indicated arginine is...
We have studied the shape of rabbit ciliary ganglion cells in relation to number axons that innervate each neuron. Adult receive synapses from one seven different preganglionic axons. Some neurons lack dendrites altogether, whereas others complex arborizations up eight primary dendrites. The all their synaptic contacts a single axon usually no dendrites; on other hand, multiply innervated increases proportion they possess. A possible explanation these results is individual comprise separate...
Significance Cells encountering physiological stresses often become vacuolated, but the source of vacuoles and their role in causing or ameliorating necrotic cell death are unclear. Studies cells responding to hypoosmotic, hypoxic, hypothermic stress revealed that 1) derived from lysosomes, 2) many subsequently undergo exocytosis, 3) blocking either vacuolation vacuole exocytosis by genetic pharmacological approaches led greatly increased death. By storing then expelling excess water,...
In the CNS, receptor recycling is critical for synaptic plasticity; however, of receptors has never been observed at peripheral synapses. Using a novel imaging technique, we show here that nicotinic acetylcholine (AChRs) recycle into postsynaptic membrane neuromuscular junction. By sequentially labeling AChRs with biotin-bungarotoxin and streptavidin-fluorophore conjugates, were able to distinguish recycled, preexisting, new pools synapses in living mice. Time-lapse revealed recycled...
It has been suggested that ATP might play a role in synaptic transmission at developing vertebrate neuromuscular junctions. To increase our understanding of the events underlying synapse formation, we have used intracellular recording and patch clamp to examine response chick myoblasts myotubes other nucleotides, ATP, applied micromolar concentrations, potent depolarizing action on myotubes. The depolarization declines during prolonged application shows no recovery for least 20 min after...
P2X receptors are ATP-gated ion channels made up of three similar or identical subunits. It is unknown whether ligand binding intersubunit intrasubunit, either for agonists allosteric modulators. Zinc binds to rat P2X2 and acts as an modulator, potentiating channel opening. To probe the location this zinc site, bearing mutations histidines at positions 120 213 were expressed in Xenopus oocytes. Studies H120C H213C mutants produced five lines evidence consistent with hypothesis that residues...
P2X receptors are ATP-gated cation channels that widely expressed in the brain. The extracellular domains of all seven contain 10 conserved cysteines, which could form disulfide bonds or binding sites for transition metals modulate receptors. To test whether these cysteines critical receptor function, we studied wild-type rat 2 and mutant receptors, each containing an alanine substituted a cysteine. Nine mutants were functional but had reduced maximum currents compared with either Xenopus...
P2X 2 receptor currents are potentiated by acidic pH and zinc. To identify residues necessary for proton zinc modulation, alanines were singly substituted each of the nine histidines in extracellular domain rat receptor. Wild‐type mutant receptors expressed Xenopus oocytes analysed with two‐electrode voltage clamp. All mutations caused less than a 2‐fold change EC 50 ATP concentration‐response relation. Decreasing from 7.5 to 6.5 responses 10 μ m wild‐type eight more 4‐fold, but response...
shocked ( sho ) is a zebrafish mutation that causes motor deficits attributable to CNS defects during the first2dof development. Mutant embryos display reduced spontaneous coiling of trunk, diminished escape responses when touched, and an absence swimming. A missense in slc6a9 gene encodes glycine transporter (GlyT1) was identified as cause phenotype. Antisense knock-down GlyT1 wild-type phenocopies , injection mRNA into mutants rescues them. comparison glycine-evoked inward currents Xenopus...
When the euryhaline decapod Carcinus maenas is transferred from sea water to a medium more dilute than 75% water, frequency of heart beat increases. The cardioacceleratory response probably mediated by external rather internal receptors, and parameter that sensed in neither total osmotic strength medium, nor concentration any single ion. Although it not yet determined whether responds hormonal or nervous signal, likely control mechanisms are similar those which mediate permeability changes...
Mutations in the gene encoding TRPM7 ( trpm7 ), a member of Transient Receptor Potential (TRP) superfamily cation channels that possesses an enzymatically active kinase at its C terminus, cause touch-unresponsive zebrafish mutant touchdown . We identified and characterized new allele , as well two previously reported alleles, found all three alleles harbor mutations abolish channel activity. Through selective restoration expression sensory neurons, we TRPM7's activity selectivity for...
The kinesin-3 family member Unc-104/KIF1A is required for axonal transport of many presynaptic components to synapses, and mutation this gene results in synaptic dysfunction mice, flies worms. Our studies at the
Micromolar concentrations of extracellular adenosine 5'-triphosphate (ATP) elicit a rapid excitatory response in developing chick skeletal muscle. Excitation is the result simultaneous increase membrane permeability to sodium, potassium, and chloride ions. In present study we quantify selectivity ATP response, provide evidence that single class ATP-activated ion channels conducts both cations anions. Experiments were performed on myoballs using whole-cell patch-clamp technique. We estimated...