Supersensitive Ras activation in dendrites and spines revealed by two-photon fluorescence lifetime imaging.
AuthorsYasuda R, Harvey CD, Zhong H, Sobczyk A, van Aelst L, Svoboda K
JournalNat Neurosci
PubMed ID16429133
'To understand the biochemical signals regulated by neural activity, it is necessary to measure protein-protein interactions and enzymatic activity in neuronal microcompartments such as axons, dendrites and their spines. We combined two-photon excitation laser scanning with fluorescence lifetime imaging to measure fluorescence resonance energy transfer at high resolutions in brain ... More
Ca2+/calmodulin-dependent protein kinase II (CaMKII) is activated by calmodulin with two bound calciums.
AuthorsShifman JM, Choi MH, Mihalas S, Mayo SL, Kennedy MB
JournalProc Natl Acad Sci U S A
PubMed ID16966599
'Changes in synaptic strength that underlie memory formation in the CNS are initiated by pulses of Ca2+ flowing through NMDA-type glutamate receptors into postsynaptic spines. Differences in the duration and size of the pulses determine whether a synapse is potentiated or depressed after repetitive synaptic activity. Calmodulin (CaM) is a ... More
Nonlinear [Ca2+] signaling in dendrites and spines caused by activity-dependent depression of Ca2+ extrusion.
AuthorsScheuss V, Yasuda R, Sobczyk A, Svoboda K
JournalJ Neurosci
PubMed ID16885232
'Spine Ca2+ triggers the induction of synaptic plasticity and other adaptive neuronal responses. The amplitude and time course of Ca2+ signals specify the activation of the signaling pathways that trigger different forms of plasticity such as long-term potentiation and depression. The shapes of Ca2+ signals are determined by the dynamics ... More
Synapse-specific plasticity and compartmentalized signaling in cerebellar stellate cells.
AuthorsSoler-Llavina GJ, Sabatini BL
JournalNat Neurosci
PubMed ID16680164
'Here we demonstrate that cerebellar stellate cells diffusionally isolate synaptically evoked signals in dendrites and are capable of input-specific synaptic plasticity. Sustained activity of parallel fibers induces a form of long-term depression that requires opening of calcium (Ca(2+))-permeable AMPA-type glutamate receptors (CP-AMPARs) and signaling through class 1 metabotropic glutamate receptors ... More
Concurrent maturation of inner hair cell synaptic Ca2+ influx and auditory nerve spontaneous activity around hearing onset in mice.
AuthorsWong AB, Jing Z, Rutherford MA, Frank T, Strenzke N, Moser T,
Journal
PubMed ID23804089
Hearing over a wide range of sound intensities is thought to require complementary coding by functionally diverse spiral ganglion neurons (SGNs), each changing activity only over a subrange. The foundations of SGN diversity are not well understood but likely include differences among their inputs: the presynaptic active zones (AZs) of ... More
Somatic spikes regulate dendritic signaling in small neurons in the absence of backpropagating action potentials.
AuthorsMyoga MH, Beierlein M, Regehr WG,
JournalJ Neurosci
PubMed ID19535592
Somatic spiking is known to regulate dendritic signaling and associative synaptic plasticity in many types of large neurons, but it is unclear whether somatic action potentials play similar roles in small neurons. Here we ask whether somatic action potentials can also influence dendritic signaling in an electrically compact neuron, the ... More
Dye loading with patch pipettes.
AuthorsEilers J, Konnerth A,
JournalCSH Protoc
PubMed ID20147143
This protocol describes the loading of individual cells with fluorescent probes via patch pipettes. The patch-clamp methodology has been successfully used for single-cell dye labeling in cultured neurons, brain slices, and in vivo preparations. A broad range of dyes can be used with this loading technique. Markers for morphological reconstruction ... More
The number of glutamate receptors opened by synaptic stimulation in single hippocampal spines.
AuthorsNimchinsky EA, Yasuda R, Oertner TG, Svoboda K
JournalJ Neurosci
PubMed ID14985448
The number of receptors opening after glutamate release is critical for understanding the sources of noise and the dynamic range of synaptic transmission. We imaged [Ca2+] transients mediated by synaptically activated NMDA receptors (NMDA-Rs) in individual spines in rat brain slices. We show that Ca2+ influx through single NMDA-Rs can ... More
Ca2+ and Mg2+ binding properties of GCAP-1. Evidence that Mg2+-bound form is the physiological activator of photoreceptor guanylyl cyclase.
AuthorsPeshenko IV, Dizhoor AM
JournalJ Biol Chem
PubMed ID16793776
Guanylyl cyclase-activating protein 1 (GCAP-1) is an EF-hand protein that activates retinal guanylyl cyclase (RetGC) in photoreceptors at low free Ca2+ in the light and inhibits it in the dark when Ca2+ concentrations rise. We present the first direct evidence that Mg2+-bound form of GCAP-1, not its cation-free form, is ... More
Modification of permeability transition pore arginine(s) by phenylglyoxal derivatives in isolated mitochondria and mammalian cells. Structure-function relationship of arginine ligands.
AuthorsJohans M, Milanesi E, Franck M, Johans C, Liobikas J, Panagiotaki M, Greci L, Principato G, Kinnunen PK, Bernardi P, Costantini P, Eriksson O
JournalJ Biol Chem
PubMed ID15671016
Methylglyoxal and synthetic glyoxal derivatives react covalently with arginine residue(s) on the mitochondrial permeability transition pore (PTP). In this study, we have investigated how the binding of a panel of synthetic phenylglyoxal derivatives influences the opening and closing of the PTP. Using both isolated mitochondria and mammalian cells, we demonstrate ... More
Role of calcium in the regulation of mechanical power in insect flight.
AuthorsGordon S, Dickinson MH
JournalProc Natl Acad Sci U S A
PubMed ID16537527
Most flying insect species use "asynchronous" indirect flight muscles (A-IFMs) that are specialized to generate high mechanical power at fast contraction frequencies. Unlike individual contractions of "synchronous" muscles, those of A-IFMs are not activated and deactivated in concert with neurogenically controlled cycling of myoplasmic [Ca(2+)] but rather are driven myogenically ... More