PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 11322969

Imaging visual function with the multifocal m-sequence technique.

E E Sutter
View original source ↗Export metadata ↓

Abstract

The multifocal m-sequence technique is a versatile set of tools for visual electrophysiology designed to provide access to the complex dynamic interplay of converging signals in the central nervous system. Here, a number of uses for the technique are demonstrated, with examples from human electroretinography. A simple relationship between the binary kernels extracted from a single experiment permits us to distinguish local from lateral interactions in the retina. Transformation of the series of binary kernels into response sequences provides new insight into unexpected fast dynamic properties of retinal responses and facilitates future modeling of the signals as well as identification of the signal sources.

Explore related subjects

ElectrophysiologyElectroretinographyHumansImage Processing, Computer-AssistedNonlinear DynamicsSystems AnalysisVisual PerceptionJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, P.H.S.

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

E E Sutter. 2001. Imaging visual function with the multifocal m-sequence technique.. https://doi.org/10.1016/s0042-6989(01)00078-5

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2003

Kv1.3 potassium channels in human alveolar macrophages.

Human alveolar macrophages were obtained from macroscopically normal lung tissue obtained at surgical resections, isolated by adherence, and identified by morphology. Whole cell recordings were made from cells 1-3 h in culture, using electrodes containing potassium chloride. From a holding potential of -100 mV, depolarizing pulses to -40 mV or greater activated an outward current. Tail current reversals showed that this current was potassium selective. Margatoxin completely blocked the current; the concentration giving half-maximal block was 160 pM. In current clamp recordings, the resting membrane potential was -34 mV; margatoxin depolarized cells to close to 0 mV. A pure macrophage population was isolated by fluorescence-activated cell sorting, using the phagocytosis of BODIPY-labeled zymosan particles. Reverse transcription-polymerase chain reaction showed that, of 13 voltage-gated K+ (Kv) potassium channels sought, only Kv1.3 mRNA was present. Margatoxin (1 nM) did not affect the percentage of cells showing phagocytosis sorted from the total population. Under these experimental conditions Kv1.3 sets the resting potential of the cells, but it is not required for Fc receptor-mediated phagocytosis.

Electrophysiology↗
PubMed2003

Kinetic determinants of agonist action at the recombinant human glycine receptor.

The amino acids glycine, beta-alanine and taurine are all endogenous agonists of the glycine receptor. In this study, a combination of rapid agonist application onto macropatches and steady-state single-channel recordings was used to compare the actions of glycine, beta-alanine and taurine upon homomeric alpha1 human glycine receptors transiently expressed in human embryonic kidney (HEK 293) cells. The 10-90 % rise times determined from rapid application of 100 microM of each agonist were indistinguishable, indicating each agonist has a similar association rate. At saturating concentrations (30 mM) the rise time for glycine (0.26 ms) was 1.8-fold faster than that for beta-alanine (0.47 ms) and 3.9-fold faster than that for taurine (1.01 ms), indicating clear differences in the maximum opening rate between agonists. The relaxation following rapid removal of agonist was fitted with a single exponential for beta-alanine (3.0 ms) and taurine (2.2 ms), and two exponential components for glycine with a weighted mean time constant of 27.1 ms. This was consistent with differences in dissociation rates estimated from analysis of bursts, with taurine > beta-alanine > glycine. Exponential fits to the open period distributions gave time constants that did not differ between agonists and the geometric distribution for the number of openings per burst indicated that all three agonists had a significant component of single-opening bursts. Based upon these data, we propose a kinetic scheme with three independent open states, where the opening rates are dependent upon the activating agonist, while the closing rates are an intrinsic characteristic of the receptor.

Electrophysiology↗