NO-ergic Control of Blood Circulation in the Medulla Oblongata of Rats with Experimental Hemiparkinsonism under Prolonged Exposure to Continuous Light

2017 ◽  
Vol 8 (4) ◽  
pp. 363-374
Author(s):  
Lyudmila M. Shapoval ◽  
Bogdan S. Kop'yak ◽  
Olga V. Dmytrenko ◽  
Volodymyr O. Mayskiy ◽  
Olena P. Mankivska ◽  
...  
Keyword(s):  
Medulla Oblongata ◽  
Blood Circulation ◽  
Prolonged Exposure ◽  
Continuous Light

scholarly journals NO-ERGIC CONTROL OF BLOOD CIRCULATION IN THE MEDULLA OBLONGATA OF RATS WITH EXPERIMENTAL HEMIPARKINSONIZM UNDER EXPOSURE TO CONTINUOUS LIGHT

2016 ◽  
Vol 62 (6) ◽  
pp. 50-59
Author(s):  
L.M. Shapoval ◽  
◽  
B.S. Kop’yak ◽  
O.V. Dmytrenko ◽  
V.O. Mayskiy ◽  
...  
Keyword(s):  
Medulla Oblongata ◽  
Blood Circulation ◽  
Continuous Light

Light-induced suppression of the rat circadian system

1995 ◽  
Vol 268 (5) ◽  
pp. R1111-R1116 ◽  
Author(s):  
P. Depres-Brummer ◽  
F. Levi ◽  
G. Metzger ◽  
Y. Touitou
Keyword(s):  
Locomotor Activity ◽  
Body Temperature ◽  
Circadian Rhythms ◽  
Prolonged Exposure ◽  
Light Exposure ◽  
Continuous Light ◽  
Circadian System ◽  
Short Exposure ◽  
Complete Suppression ◽  
Continuous Darkness

In a constant environment, circadian rhythms persist with slightly altered period lengths. Results of studies with continuous light exposure are less clear, because of short exposure durations and single-variable monitoring. This study sought to characterize properties of the oscillator(s) controlling the rat's circadian system by monitoring both body temperature and locomotor activity. We observed that prolonged exposure of male Sprague-Dawley rats to continuous light (LL) systematically induced complete suppression of body temperature and locomotor activity circadian rhythms and their replacement by ultradian rhythms. This was preceded by a transient loss of coupling between both functions. Continuous darkness (DD) restored circadian synchronization of temperature and activity circadian rhythms within 1 wk. The absence of circadian rhythms in LL coincided with a mean sixfold decrease in plasma melatonin and a marked dampening but no abolition of its circadian rhythmicity. Restoration of temperature and activity circadian rhythms in DD was associated with normalization of melatonin rhythm. These results demonstrated a transient internal desynchronization of two simultaneously monitored functions in the rat and suggested the existence of two or more circadian oscillators. Such a hypothesis was further strengthened by the observation of a circadian rhythm in melatonin, despite complete suppression of body temperature and locomotor activity rhythms. This rat model should be useful for investigating the physiology of the circadian timing system as well as to identify agents and schedules having specific pharmacological actions on this system.

Chronopharmacological study of furosemide; (VI) influence of prolonged exposure to continuous light

Life Sciences ◽  
1990 ◽  
Vol 47 (18) ◽  
pp. 1641-1646 ◽  
Author(s):  
Akio Fujimura ◽  
Kyo-ichi Ohashi ◽  
Akio Ebihara
Keyword(s):  
Prolonged Exposure ◽  
Continuous Light

Effect of light and temperature on number and length of Helminthosporium gramineum conidia produced in culture

1976 ◽  
Vol 54 (7) ◽  
pp. 644-648 ◽  
Author(s):  
Beth L. Teviotdale ◽  
Dennis H. Hall
Keyword(s):  
Low Temperature ◽  
Prolonged Exposure ◽  
Continuous Light ◽  
Fluorescent Light ◽  
Conidium Formation ◽  
Barley Leaf ◽  
Reduced Temperature ◽  
Effect Of Light

Helminthosporium gramineum sporulated in culture when grown at 26 °C on barley leaf pieces on 1.5% water agar and then exposed to fluorescent light at intensities of 0.0045, 0.0076, and 0.0338 cal cm−1 s−2 (1 cal = 4.184 J) followed by incubation at 6, 12, 18, or 24 °C. The number of conidia produced increased with time of irradiation and time at low temperature. Length of conidia at maturity was increased by prolonged exposure to low temperature and the greatest mean length of conidia occurred after 16 h at 12 °C. A lapse of time between irradiation and exposure to reduced temperature resulted in sterile conidiophores. Sporulation occurred in continuous light and constant temperatures from 12 to 18 °C, but a reduction in temperature after irradiation at 24 °C or above was necessary for formation of conidia. Conidium formation was inhibited by constant temperatures above 21 °C but not by light at any temperature.

scholarly journals Neurophysiological justification of the G. F. Lang hypothesis about the occurrence of essential hypertension

2021 ◽  
Vol 27 (5) ◽  
pp. 499-508
Author(s):  
E. V. Shlyakhto ◽  
V. A. Tsyrlin ◽  
N. V. Kuzmenko ◽  
M. G. Pliss
Keyword(s):  
Spinal Cord ◽  
Essential Hypertension ◽  
Arterial Hypertension ◽  
Neuronal Activity ◽  
Paraventricular Nucleus ◽  
Medulla Oblongata ◽  
Blood Circulation ◽  
Vascular Tone ◽  
Morphological Changes ◽  
Sympathetic Neurons

This article is an analysis of modern data on the morphological, functional and neurochemical organization of the central mechanisms of blood circulation regulation, the violation of which can cause the development of essential hypertension. The data indicating the validity of the hypothesis of G.F. Lang that prolonged emotional stress leads to a violation of the neuronal activity of the hypothalamus structures are presented. The article describes the morphological connections of the hypothalamus with the neurons of the ventrolateral region of the medulla oblongata and the structures of the spinal cord that provide neurogenic vascular tone. The evidence of convergence of axons of neurons of the paraventricular nucleus of the hypothalamus on the preganglionic neurons of the spinal cord is presented. Neurochemical processes in the vasomotor center of the medulla oblongata are considered, morphological changes of preganglionic sympathetic neurons in experimental arterial hypertension are indicated.

Acupuncture Attenuates Hyperglycaemia and Improves Ovarian Function in Female Rats Subjected to Continuous Light Exposure

2017 ◽  
Vol 35 (5) ◽  
pp. 352-359 ◽  
Author(s):  
Xuezhi Kang ◽  
Lina Jia ◽  
Yaming Li ◽  
Xu Zhang
Keyword(s):  
Blood Glucose ◽  
Ovarian Function ◽  
Prolonged Exposure ◽  
Light Exposure ◽  
Fasting Blood Glucose ◽  
Continuous Light ◽  
Female Rats ◽  
Glucose Levels ◽  
The Metabolic Syndrome ◽  
Blood Glucose Levels

Objective Exposure to unnatural light cycles is increasingly associated with obesity and the metabolic syndrome. The purpose of this study was to examine the effects of electroacupuncture (EA) on glucose metabolism and ovarian function in female rats subjected to long-term continuous light exposure. Methods Female Sprague-Dawley rats (n=24) were divided into three experimental groups: an LD group that was maintained under a normal light-dark cycle (healthy control); an LL group that was exposed to continuous light for 21 weeks but remained untreated; and an LL+EA group that received EA at ST36 and SP6 during weeks 17 to 21 of continuous light exposure. Results Oestrous cycles of female rats kept in a continuously lit environment for 21 weeks were disordered and polycystic ovarian syndrome (PCOS)-like changes occurred, accompanied by increased fasting blood glucose (6.23±0.33 vs 5.27±0.40 mmol/L in week 17, p=0.015) and reduced fasting levels of serum testosterone (0.07±0.018 vs 0.12±0.058 ng/L, p=0.043) and insulin (0.89±0.20 vs 1.43±0.46 ng/L, p=0.006). After 5 weeks of EA treatment at ST36 and SP6, ovarian cycle disruption was mitigated and blood glucose levels showed a gradual decline (5.18±0.37 vs 5.80±0.55 mmol/L, p=0.017; and 5.73±0.31 vs 6.62±0.13 mmol/L, p=0.004; in the fourth and fifth weeks of EA treatment, respectively). EA also attenuated the reductions otherwise seen in serum insulin and testosterone levels. Conclusion Prolonged exposure to light can lead to a decline in ovarian and pancreatic function. EA at ST36 and SP6 may reduce abnormally elevated blood glucose levels and improve ovarian and pancreatic hormone levels.

Examination of Pituitary and Ovarian Variables during a 24-Hour Period in Rats after Prolonged Exposure to Continuous Light

1973 ◽  
Vol 13 (3) ◽  
pp. 139-150 ◽  
Author(s):  
Bigitte G. Mann ◽  
W.L. Talley ◽  
Carol M. Proudfit ◽  
Neena B. Schwartz
Keyword(s):  
Prolonged Exposure ◽  
Continuous Light

A Therapist's Guide to Prolonged Exposure

PsycCRITIQUES ◽  
2008 ◽  
Vol 53 (30) ◽  
Author(s):  
Susan P. Stevens ◽  
Maha H. Zayed
Keyword(s):  
Prolonged Exposure
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