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Electrophysiology* ; Neuroendocrine Cells*

China ; Electrophysiology ; trends ; Humans

In cross sectional fashion we recoreded the cone response in 98 adult diabetics and 20 normal controls according to the recommendation by the International Society for Clinical Electrophysiology of Vision. The photopic oscillatory potentials were extracted from the cone response by highpass filtering. The clear media and attached retina were criteria for inclusion in this study. The data were statistically analyzed expecting that this procedure may provide a feature that could have some clinical significance. The analysis of variance demonstrated that the summed amplitude of the oscillatory potentials, and second oscillatory potential amplitude were the most sensitive parameters to the diabetic retina. A timing delay in the first oscillatory potential wavelet, and a reduction in the second oscillatory potential amplitude and the summed amplitude of oscillatory potentials were the commonest abnormalities. Hence, the second oscillatory potential amplitude and the summed amplitude of oscillatory potentials may be the most valuable indicator among the photopic electroretinogram parameters representing a quantitative measure of overall retinal dysfunction.
Adult* ; Electrophysiology ; Humans ; Retina ; Retinaldehyde

Saccades are rapid eye movements that shift the line of sight between successive points of fixation. The cerebellum calibrates saccadic amplitude (dorsal vermis and fastigial nucleus) and the saccadic pulse-step match (flocculus) for optimal visuo-ocular motor behavior. Based on electrophysiology and the pharmacological inactivation studies, early activity in one fastigial nucleus could be important for accelerating the eyes at the beginning of a saccade, and the later activity in the other fastigial nucleus could be critical for stopping the eye on target, which is controlled by inhibitory projection from the dorsal vermis. The cerebellum could monitor a corollary discharge of the saccadic command and terminate the eye movement when it is calculated to be on target. The fastigial nucleus and dorsal vermis also participate in the adaptive control of saccadic accuracy.
Cerebellum ; Electrophysiology ; Eye Movements ; Saccades* ; Sleep, REM

Computer-Assisted Instruction(CAI) improved the possibility of individualized learning by enhancing the learning efficacy related to the apptitude, competency, speed and perceptual style of each learner. The reason that I introduced the computer in teaching and learning process is based on the assumption that individual differences can be minimized by applying CAI. This has special meaning because in the current teaching and learning system we can not consider the individual differences of learners. Considering the importance of developing individualized learning program, the course of electrophysiology and pathology of K that requires typical memorization and repetition is made as a purpose to increase the efficacy of learning and thus improve the quality of nursing curriculum.
Curriculum ; Electrophysiology ; Individuality ; Learning ; Nursing ; Pathology

BACKGROUND AND OBJECTIVES: In radiofrequency catheter ablation (RFCA), it is an essential point to understand the characteristics of local electrograms at arrhythmic focus. However controversy exists as whether the unipolar or bipolar electrogram is superior in detecting arrhythmic focus. SUBJECTS AND METHODS: We evaluated the characteristics of unipolar and bipolar electrograms at ventricular tachycardia (VT) origin. Electroanatomical mapping and RFCA were performed in 6 patients with idiopathic VT. 22 sites were enrolled and 6 of them were successful sites. We analyzed the relationship between surface and local electrograms in accordance with success or failure. We also analyzed the morphology of local electrograms. RESULTS: At successful sites of RFCA, point of unipolar onset (22.86+/-10.82 msec vs 5.47+/-26.31 msec, p<0.05) and maximal negative slope (16.57+/-17.46 msec vs -4.00+/-22.77 msec, p<0.05) were recorded earlier than unsuccessful sites. R wave amplitude (0.11+/-0.19 mm vs 0.64+/-0.57 mm, p<0.05) and R/S ratio (0.02+/-0.30 vs 0.18+/-0.26, p<0.05) of unipolar electrograms were smaller at successful sites. R wave duration was shorter at successful sites (6.29+/-8.49 msec vs 11.33+/-6.26 msec) but there was no statistical significance. QRS duration of bipolar electrograms was longer at successful sites (66.14+/-17.93 msec vs 49.07+/-13.11 msec, p<0.05). CONCLUSION: In electranatomical mapping for VT, point of unipolar onset and maximal negative slope could predict local activation time more precisely Unipolar electrograms showed shorter R wave duration and smaller R/S ratio at successful sites of RFCA. We can estimate the focus of VT by using these chracteristics of unipolar and bipolar electrogram.
Catheter Ablation ; Electrophysiology ; Humans ; Tachycardia, Ventricular*

Here we describe and illustrate our methods for multi-channel in vivo recording in mice, including the fabrication of the microdrive array and the surgical procedure for implanting electrodes. The multi-channel microdrive is fabricated from printed circuit board base, screws, nuts and clamping screws. Rotation of the screw drives both the nut and the attached electrodes to move forward simultaneously. Each full turn of the screw corresponds to 280 µm in depth penetration. The recording electrodes are self-made tetrodes consisting 4 wires (13 µm in diameter). The major steps of headstage fabrication include: tetrode making, microdrive construction, headstage assembling and tetrode plating. The finished headstage is suitable for multi-channel recording in freely moving rodents with the modest weight and the adjustable number of recording electrodes. Additionally, the recording site is allowed to be manipulated after implantation at any time. In the latter part of this paper, we introduce the procedure of the implant surgery to record in bilateral hippocampus in mice. Using these headstages, we simultaneously recorded population activity in bilateral CA1 in freely behaving mice.
Animals ; Electrodes, Implanted ; Electrophysiology ; instrumentation ; Hippocampus ; Mice

Electroretinography has been used clinically for more than 50 years as useful retinal function test. But there has been no uniform recording signals, since various laboratories have employed different technologies and recording condition. Therefore, in 1989, International Society for clinical Electrophysiology of Vision (ISCEV) published Standard for clinical ERG, to ensure that ERG performed simply and uniformly worldwide for clinical and research purpose. We performed this standard ERG to 100 normal subjects whose range of ages were 8-79 years old. We obtained normal values of standard 5 basic response parameter. Additionally, we studied the parameter change according to age and sex. We found significantly decreased amplitude in the b-wave with age (p<0.05), and also obtained decreased rate b-wave amplitude with age. But no relation between b-wave implicit time and change of age was noted. B-wave amplitude found to be higher in women than in men (p<0.05).
Electrophysiology ; Electroretinography* ; Female ; Humans ; Male ; Reference Values* ; Retinaldehyde

BACKGROUND/AIMS: Long-term antiarrhythmic drug therapy remains the principal approach for suppressing atrial fibrillation (AF) and maintaining sinus rhythm. In this study, we examined the differing electrophysiological effects of various antiarrhythmic drugs on the cardiac chamber and atrial selectivity in patients with AF. METHODS: We analyzed 134 patients (60.4 +/- 12.5 years, M:F = 1.14:1) who were administered a single antiarrhythmic agent for AF over 6 months: amiodarone (group A), flecainide (group F), or propafenone (group P). The P wave, QRS complex duration and dispersion, and QT interval and its dispersion were evaluated using a standard 12-lead electrocardiogram. RESULTS: There was no significant difference in age, gender ratio, or associated diseases among the three groups. In group A, Pmax, Pmin, P dispersion, QRSmax, QRSmin, and QRS dispersion were shorter than in groups F and P, whereas Pmax/QRSmax was the highest in group A (A = 1.2, F = 0.9, P = 1.0; p < 0.01). QTcmax and QTcmin were longer in group A, whereas QTc dispersion and the QT peak to end (A = 13.3 +/- 11.2, F = 30.7 +/- 24.9, P = 31.8 +/- 21.6; p < 0.01) were shorter in group A than in the other groups. CONCLUSIONS: Amiodarone had a weaker, but more selective, inhibitory effect on intra-atrial conduction, and inhibited ventricular repolarization more effectively and homogenously than flecainide or propafenone. These differing electrophysiological effects may contribute to the superior effectiveness and safety of amiodarone over flecainide or propafenone.
Amiodarone ; Anti-Arrhythmia Agents ; Atrial Fibrillation ; Electrophysiology ; Flecainide ; Humans ; Propafenone

PURPOSE: To investigate the clinical significance of electroretinographic (ERG) responses, including the photopic negative response parameter, in assessing the progression of diabetic retinopathy. METHODS: Standard flash ERG was tested on 28 normal controls and 143 patients who were diagnosed with diabetes mellitus. Of those, 97 patients had diabetic retinopathy in different stages. Electroretinography was performed according to the International Society for Clinical Electrophysiology of Vision (ISCEV) standards. Amplitudes and implicit times of ERG responses, including the photopic negative response (PhNR), were compared at different stages of diabetic retinopathy. RESULTS: Amplitudes of oscillatory potentials were significantly reduced in mild NPDR. Cone b-wave amplitude, 30--Hz flicker response, and PhNR were significantly reduced in moderate NPDR. CONCLUSIONS: These results suggest that oscillatory potentials are good indicators of retinal function change in the early stage of diabetic retinopathy, and the appropriate results of the cone b-wave, 30-Hz flicker response and PhNR tests are good indicators of moderate NPDR.
Diabetes Mellitus ; Diabetic Retinopathy ; Electrophysiology ; Electroretinography ; Humans ; Retinaldehyde ; Vision, Ocular