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F J Gu

Publications and source records attributed to F J Gu.

2 recordsLinked to original sources

Forward masking effects on early auditory evoked potentials.

In early auditory evoked potentials (EAEPs) evoked by click trains, every click had a masking effect on the responses to the clicks following it and the whole response evoked by the click train was the sum of the masked responses to every click in the train. Special attention was paid to the situation when the inter-stimulus interval (ISI) was less than 10 ms and the responses to the individual clicks might be merged to form a continuous wave. The experiments showed that the more the number of the clicks preceding a given click in the train, the stronger the effect on the response to this click until the number was big enough and the effect became saturated; the shorter the ISI when it was less than 10 ms, the stronger the effect; the higher the intensity of the masker, the stronger the effect.

Acoustic Stimulation↗

A quantitative model of myosin phosphorylation and the photomechanical response of the isolated sphincter pupillae of the frog iris.

The time courses of isometrically recorded photomechanical responses of isolated sphincter pupillae of Rana pipiens can be accurately predicted by a set of differential equations derived from phosphorylation theory of smooth muscle contraction. We compared actual light-stimulated contractions with calculated ones over a wide range of stimulus intensities (56-fold) and durations (0.4-4.0 s). The hypothetical Ca++-calmodulin-myosin light chain kinase cascade acts as a "valve" to control the flow of ATP through a phosphorylation-dephosphorylation cycle. When the rate of flow of ATP through the phosphorylation-dephosphorylation cycle is increased, the percentage of phosphorylated myosin increases. The time courses of the concentrations of phosphorylated myosin during different responses are seen to be functions of the time courses of the opening and closing of the coupling cascade "valve." The calculations predict experimentally measurable intermediate variables, which can aid the investigation of the application of quantitative phosphorylation theory to amphibian sphincter pupillae and to smooth muscle in general.

Adenosine Triphosphate↗