Oscillographic method for measurement of functional lability and refractory phase of nerves

1957 ◽  
Vol 44 (S1) ◽  
pp. 145-148
Author(s):  
P. I. Gulyaev
Keyword(s):  
Oscillographic Method ◽  
Refractory Phase

scholarly journals The refractory phase in a reflex arc

1922 ◽  
Vol 56 (6) ◽  
pp. 426-443 ◽  
Author(s):  
E. D. Adrian ◽  
J. M. D. Olmsted
Keyword(s):  
Reflex Arc ◽  
Refractory Phase

Influence of photoperiod and gonadal status on food intake, adiposity, and gene expression of hypothalamic appetite regulators in a seasonal mammal

2007 ◽  
Vol 292 (1) ◽  
pp. R242-R252 ◽  
Author(s):  
Chantacha Anukulkitch ◽  
Alexandra Rao ◽  
Frank R. Dunshea ◽  
Dominique Blache ◽  
Gerald A. Lincoln ◽  
...  
Keyword(s):  
Gene Expression ◽  
Food Intake ◽  
Arcuate Nucleus ◽  
Leptin Receptor ◽  
Reproductive Axis ◽  
Pomc Gene ◽  
Gonadal Status ◽  
Long Photoperiod ◽  
Refractory Phase

We studied the effects of photoperiod on metabolic profiles, adiposity, and gene expression of hypothalamic appetite-regulating peptides in gonad-intact and castrated Soay rams. Groups of five to six animals were studied 6, 18, or 30 wk after switching from long photoperiod (LP: 16 h of light) to short photoperiod (SP: 8 h of light). Reproductive and metabolic indexes were measured in blood plasma. Expression of neuropeptide Y (NPY), proopiomelanocortin (POMC), and leptin receptor (ObRb) in the arcuate nucleus was measured using in situ hybridization. Testosterone levels of intact animals were low under LP, increased to a peak at 16 wk under SP, and then declined. Voluntary food intake (VFI) was high under LP in both intact and castrated animals, decreased to a nadir at 12–16 wk under SP, and then recovered, but only in intact rams as the reproductive axis became photorefractory to SP. NPY gene expression varied positively and POMC expression varied negatively with the cycle in VFI, with differences between intact and castrate rams in the refractory phase. ObRb expression decreased under SP, unrelated to changes in VFI. Visceral fat weight also varied between the intact and castrated animals across the cycle. We conclude that 1) photoperiodic changes in VFI reflect changes in NPY and POMC gene expression, 2) changes in ObRb gene expression are not necessarily determinants of changes in VFI, 3) gonadal status affects the pattern of VFI that changes with photoperiod, and 4) in the absence of gonadal factors, animals can eat less but gain adiposity.

The Porosity of the Aluminum Surface Investigated by the Repetitive Oscillographic Method

CORROSION ◽  
1955 ◽  
Vol 11 (9) ◽  
pp. 27-30
Author(s):  
W. MACHU ◽  
E. M. KHAIRY ◽  
M. K. HUSSEIN
Keyword(s):  
Aluminum Surface ◽  
Oscillographic Method

An Oscillographic Method for the Photometry of Photographic Flash Lamps

1945 ◽  
Vol 16 (3) ◽  
pp. 51-53 ◽  
Author(s):  
T. H. Projector ◽  
L. E. Barbrow
Keyword(s):  
Oscillographic Method

scholarly journals Effect of external lighting on biopotential of maize leaves caused by pulsed temperature stimulation

2017 ◽  
Vol 8 (2) ◽  
pp. 179-184
Author(s):  
M. P. Motsnyj ◽  
N. P. Botsva ◽  
О. V. Elina ◽  
D. V. Chernetchenko ◽  
L. Y. Sadovskaya ◽  
...  
Keyword(s):  
Computer Software ◽  
Plant Cells ◽  
Cold Stimulation ◽  
Time Period ◽  
The Stability ◽  
Adaptive Ability ◽  
And Behavior ◽  
External Stimuli ◽  
Temperature Stimulation ◽  
Refractory Phase

Study of electrophysiological indicators of the condition and behavior of plants has become more important in the development of farming activities and the search for effective ways to improve the productivity of crops. The influence of external light on the adaptive ability of corn leaf cells to rhythmic cold stimulation was determined experimentally. The method of rhythmic cold stimulation is not adequate for the studied plants, but its application allows us to evaluate the stability of plant cells to external stimuli. The method consists in repeating irritation during the time period of less duration than the relative refractory phase, which causes a response of less than the previous amplitude. Because of this in the system there is a negative feedback that leads to stabilization of the amplitude of biopotentials that are registered. Rhythmic cold stimulation was applied to the leaf with the help of a quick-response thermostimulator. Rhythmic cold stimuli and settings of pulses were set by computer software. Cooling temperature was controlled using miniature differential thermocouple. Potentials of the leaf surface were diverted by an unpolarized macroelectrode and after a preamplifier fed to the input of the USB oscilloscope connected to the computer. Analysis of the results of experiments was performed using automated developed software. As a result, we experimentally established that rhythmic stimulation of leaves by cold leads to stabilization of responding potential. The level of stabilization depends on the frequency of cold stimuli and describes the adaptive properties of the system causing the biopotential. We found that the absence of photosynthesis when there is a deficit outdoor lighting leads to a significant increase in the average level of stabilized responses, indicating increased stability of the system to external influences. The maximum of this increase fell on the fourth day. This increase is likely to be due to the restructuring of functional ion transport through cell membranes, generating potentials registered. In the interval 4–9th days there was a significant decrease in stabilization, probably due to adaptation of plant cells to a lack of light, or depletion of ATP, which provides the active transport of ions across the cell membrane. 

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