Laser photolysis of caged compounds at 405nm: Photochemical advantages, localisation, phototoxicity and methods for calibration

Trigo, Federico F.; Corrie, John E. T.; Ogden, David

doi:10.1016/j.jneumeth.2009.01.032

Cited by 76 publications

(102 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Our strategy was to establish a recording from a synaptically connected pair of MLIs and to find the synaptic contacts between the two neurons. We then produced a rapid and uniform increase of intracellular Ca 2+ by photolysis of the caged-calcium chelator 1-(2-nitro-4,5-dimethoxyphenyl)-N,N,N′,N′-tetrakis[(oxycarbonyl)methyl]-1,2-ethanediamine (DMnitrophen) (21) with a laser spot similar in size (diameter of 1-5 μm) to the presynaptic terminal (22) (Fig. 1A).…”

Section: Resultsmentioning

confidence: 99%

Readily releasable pool of synaptic vesicles measured at single synaptic contacts

Trigo

Sakaba

Ogden

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

To distinguish between different models of vesicular release in brain synapses, it is necessary to know the number of vesicles of transmitter that can be released immediately at individual synapses by a high-calcium stimulus, the readily releasable pool (RRP). We used direct stimulation by calcium uncaging at identified, singlesite inhibitory synapses to investigate the statistics of vesicular release and the size of the RRP. Vesicular release, detected as quantal responses in the postsynaptic neuron, showed an unexpected stochastic variation in the number of quanta from stimulus to stimulus at high intracellular calcium, with a mean of 1.9 per stimulus and a maximum of three or four. The results provide direct measurement of the RRP at single synaptic sites. They are consistent with models in which release proceeds from a small number of vesicle docking sites with an average occupancy around 0.7.release site | exocytosis | interneurons | cerebellum

show abstract

Section: Resultsmentioning

confidence: 99%

Readily releasable pool of synaptic vesicles measured at single synaptic contacts

Trigo

Sakaba

Ogden

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Brain tissue will significantly scatter the 405-nm light used here for photolysis (Trigo et al, 2009a), making the actual point-spread function in the slice wider than the one measured in the preceding paragraph. To functionally test the spatial resolution, we performed a series of experiments in which the laser was sequentially Laser-evoked ASCs are heterogeneous across release sites (Auger and Marty, 1997;Nusser et al, 1997).…”

Section: Neuron Simulationsmentioning

confidence: 91%

“…Laser pulse duration was 100 µs, and laser power was between 1 and 2.5 mW under the objective. The calibration of laser photolysis and additional details are given elsewhere (Trigo et al, 2009a). Lyophilized DM-nitrophen (Synaptic Systems) was dissolved in KOH solution in a 1:4 (DM-nitrophen/K + ) proportion and stored at 20°C.…”

Section: Electrophysiologymentioning

confidence: 99%

Impact of single-site axonal GABAergic synaptic events on cerebellar interneuron activity

Martín¹,

Jalil²,

Trigo³

2015

J Cell Biol

Self Cite

View full text Add to dashboard Cite

“…1A) (Russell et al, 2010(Russell et al, , 2012. This offers advantages over caging groups that only respond to UV light in terms of the cost of effective light sources for photolysis, reduced scattering in tissue, and lower phototoxicity (Trigo et al, 2009). Liquid chromatography-mass spectrometry analysis confirmed that CNV-NLX cleanly converts to NLX upon illumination at 405 nm (Supplemental Fig.…”

Section: Resultsmentioning

confidence: 97%

Caged Naloxone Reveals Opioid Signaling Deactivation Kinetics

Banghart¹,

Williams²,

Shah³

et al. 2013

Molecular Pharmacology

View full text Add to dashboard Cite

The spatiotemporal dynamics of opioid signaling in the brain remain poorly defined. Photoactivatable opioid ligands provide a means to quantitatively measure these dynamics and their underlying mechanisms in brain tissue. Although activation kinetics can be assessed using caged agonists, deactivation kinetics are obscured by slow clearance of agonist in tissue. To reveal deactivation kinetics of opioid signaling we developed a caged competitive antagonist that can be quickly photoreleased in sufficient concentrations to render agonist dissociation effectively irreversible. Carboxynitroveratrylnaloxone (CNV-NLX), a caged analog of the competitive opioid antagonist NLX, was readily synthesized from commercially available NLX in good yield and found to be devoid of antagonist activity at heterologously expressed opioid receptors. Photolysis in slices of rat locus coeruleus produced a rapid inhibition of the ionic currents evoked by multiple agonists of the m-opioid receptor (MOR), but not of a-adrenergic receptors, which activate the same pool of ion channels. Using the high-affinity peptide agonist dermorphin, we established conditions under which light-driven deactivation rates are independent of agonist concentration and thus intrinsic to the agonist-receptor complex. Under these conditions, some MOR agonists yielded deactivation rates that are limited by G protein signaling, whereas others appeared limited by agonist dissociation. Therefore, the choice of agonist determines which feature of receptor signaling is unmasked by CNV-NLX photolysis.

show abstract

Laser photolysis of caged compounds at 405nm: Photochemical advantages, localisation, phototoxicity and methods for calibration

Cited by 76 publications

References 32 publications

Readily releasable pool of synaptic vesicles measured at single synaptic contacts

Readily releasable pool of synaptic vesicles measured at single synaptic contacts

Impact of single-site axonal GABAergic synaptic events on cerebellar interneuron activity

Caged Naloxone Reveals Opioid Signaling Deactivation Kinetics

Contact Info

Product

Resources

About