scholarly journals Parasympathetic influences on emmetropization in chicks: Evidence for different mechanisms in form deprivation vs negative lens-induced myopia

2012 ◽  
Vol 102 ◽  
pp. 93-103 ◽  
Author(s):  
Debora L. Nickla ◽  
Falk Schroedl
Keyword(s):  
Parasympathetic Influences

Form and magnitude of beta-sympathetic and parasympathetic influences on pulse transit time

1995 ◽  
Vol 32 (4) ◽  
pp. 329-334 ◽  
Author(s):  
RICHARD J. CONTRADA ◽  
ALBERTO BO ◽  
LINDA LEVY ◽  
THEODORE WEISS
Keyword(s):  
Transit Time ◽  
Pulse Transit Time ◽  
Parasympathetic Influences

scholarly journals Diurnal variations of the dominant cycle length of chronic atrial fibrillation

2001 ◽  
Vol 280 (1) ◽  
pp. H401-H406 ◽  
Author(s):  
Carl J. Meurling ◽  
Johan E. P. Waktare ◽  
Fredrik Holmqvist ◽  
Antti Hedman ◽  
A. John Camm ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Cycle Length ◽  
Vagal Tone ◽  
Chronic Atrial Fibrillation ◽  
Frequency Domain Analysis ◽  
Diurnal Variations ◽  
Diurnal Fluctuation ◽  
Cycle Lengths ◽  
Parasympathetic Influences ◽  
Atrial Effective Refractory Period

High-resolution digital Holter recording was carried out in 21 patients (15 men, 64 ± 12 yr) with chronic atrial fibrillation. Dominating atrial cycle length (DACL) was derived by frequency domain analysis of QRST-reduced electrocardiograms. Daytime mean DACL was 150 ± 17 ms, and nighttime mean was 157 ± 22 ms ( P = 0.0002). Diurnal fluctuation in DACL differed among patients: it tended to be virtually absent in those with a short mean DACL, but in those with longer DACL the night-day difference was as much as 23 ms ( R = 0.72, P < 0.001, correlation of mean DACL to night-day difference). Mean DACL also correlated with ventricular cycle length ( R = 0.40, P < 0.001), particularly at night ( r = 0.49). The shorter cycle lengths found in this study during the day are consistent with sympathetic and/or other physiological modulation, but since increased vagal tone shortens atrial refractoriness in most models, parasympathetic influences are not likely to play a major role. Alternatively, atrial effective refractory period may not be the sole determinant of atrial cycle length during atrial fibrillation.

Effect of pharmacological blockade on cardiovascular responses to voluntary and forced diving in muskrats.

1995 ◽  
Vol 198 (11) ◽  
pp. 2307-2315 ◽  
Author(s):  
P E Signore ◽  
D R Jones
Keyword(s):  
Heart Rate ◽  
Neural Control ◽  
Peripheral Resistance ◽  
Cardiovascular Responses ◽  
Adrenergic Blocker ◽  
Adrenergic Blockers ◽  
Pharmacological Blockade ◽  
Parasympathetic Influences ◽  
Neural Effect

Neural control of free and forced diving bradycardia and peripheral resistance was studied in the muskrat (Ondatra zibethicus) by means of acute pharmacological blockade with the muscarinic blocker atropine, the alpha-adrenergic blocker phentolamine and the beta-adrenergic blockers nadolol and propranolol. Saline injection was used as a control. Heart rate in control animals increased before voluntary dives and dropped markedly as soon as the animals submerged. Heart rate started increasing towards the end of voluntary dives and reached pre-dive values within the first 5 s of recovery. Pre-dive and post-dive tachycardia were reduced in beta-blocked animals, emphasizing the role of the sympathetic system during the preparatory and recovery periods of voluntary dives. Diving bradycardia and the acceleration in heart rate before surfacing were abolished by atropine and unaffected by nadolol, demonstrating the importance of vagal efferent activity during diving. The results after blockade with nadolol suggest that there is an accentuated antagonism between the two branches of the autonomic nervous system during diving, so that parasympathetic influences on the heart predominate. Propranolol-treated muskrats had a higher diving heart rate than saline- and nadolol-treated animals, which may be due to a sedative effect caused by propranolol crossing the blood-brain barrier, a blockade of central catecholaminergic pathways or a peripheral neural effect, due to the anaesthetic properties of propranolol. Phentolamine did not affect diving bradycardia, indicating that diving bradycardia occurs independently of peripheral vasoconstriction.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals A New Look at Cardiac Defense: Attention or Emotion?

2003 ◽  
Vol 6 (1) ◽  
pp. 60-78 ◽  
Author(s):  
Jaime Vila ◽  
María Carmen Fernández ◽  
Joaquín Pegalajar ◽  
María Nieves Vera ◽  
Humbelina Robles ◽  
...  
Keyword(s):  
Psychological Research ◽  
Cognitive Approach ◽  
Psychological Mechanisms ◽  
Health And Illness ◽  
Parametric Studies ◽  
Parasympathetic Influences ◽  
New Perspective ◽  
Natural Settings ◽  
Traditional Approaches ◽  
New Look

The study of cardiac defense has a long tradition in psychological research both within the cognitive approach—linked to Pavlov, Sokolov, and Graham's work on sensory reflexes—and within the motivational one—linked to the work of Cannon and subsequent researchers on the concepts of activation and stress. These two approaches have been difficult to reconcile in the past. We summarize a series of studies on cardiac defense from a different perspective, which allows integration of the traditional approaches. This new perspective emphasizes a sequential process interpretation of the cardiac defense response. Results of descriptive and parametric studies, as well as those of studies examining the physiological and psychological mechanisms underlying the response, show a complex response pattern with both accelerative and decelerative components, with both sympathetic and parasympathetic influences, and with both attentional and emotional significance. The implications of this new look at cardiac defense are discussed in relation to defensive reactions in natural settings, the brain mechanisms controlling such reactions, and their effects on health and illness.

Changes in Swallowing-Related Tachycardia and Respiratory Arrhythmia Induced by Modulation of Tonic Parasympathetic Influences

2003 ◽  
Vol 35 (6) ◽  
pp. 434-444 ◽  
Author(s):  
O. P. Sheroziya ◽  
V. V. Ermishkin ◽  
E. V. Lukoshkova ◽  
E. P. Mazygula ◽  
V. B. Ryb'yakova ◽  
...  
Keyword(s):  
Respiratory Arrhythmia ◽  
Parasympathetic Influences

The effect of percutaneous electrical stimulation of the spinal cord on autonomic reactions in the acute period of rehabilitation after ischemic stroke

2021 ◽  
Author(s):  
Y.Y. Bikbaeva ◽  
D.A. Pavlov ◽  
A.S. Kuznetsov ◽  
E.S. Balykina ◽  
I.V. Antipov
Keyword(s):  
Spinal Cord ◽  
Nervous System ◽  
Electrical Stimulation ◽  
Ischemic Stroke ◽  
Neurological Disorders ◽  
Acute Period ◽  
Before And After ◽  
Parasympathetic Influences ◽  
Circulatory Disorders ◽  
Stimulation Of

The effect of percutaneous electrical stimulation of the spinal cord on the reactions of the autonomic nervous system in patients after acute cerebral circulatory disorders was evaluated. Patients in the acute period of rehabilitation treatment underwent a course of percutaneous electrical stimulation for 10 days. Before and after rehabilitation, vegetative reactions were assessed using an orthoclinostatic test, an A.M.Wein questionnaire, and neurological disorders on the Scandinavian scale. The inclusion of the course of percutaneous electrical stimulation in the program of physical rehabilitation of patients who have suffered an ischemic stroke indicates an improvement in the motor status of patients and a decrease in the imbalance of sympathetic and parasympathetic influences Keywords: ischemic stroke, percutaneous electrical stimulation of the spinal cord, vegetative reactions

scholarly journals Modulation of Baroreflex Function by Rosiglitazone in Prediabetic Hyperglycemic Rats

2012 ◽  
pp. 443-452 ◽  
Author(s):  
L.-Z. HONG ◽  
Y.-C. CHAN ◽  
M.-F. WANG ◽  
J.-Y. WANG ◽  
S.-W. HUNG ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Baroreflex Sensitivity ◽  
Postprandial Blood Glucose ◽  
Linear Regression Method ◽  
Prediabetic State ◽  
Insulin Sensitizer ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Parasympathetic Influences ◽  
Cardiovascular Variables

Baroreflex sensitivity (BRS) is abnormal in the prediabetic state. This study was conducted to determine effects of chronic rosiglitazone (RSG), an insulin sensitizer, on BRS in prediabetic hyperglycemic (PDH) rats induced by nicotinamide and streptozotocin. The fasting and postprandial blood glucose levels were 5.6–6.9 and 7.8–11.0 mmol/l, respectively. Rats were treated with RSG or saline for 12 weeks. BRS response to phenylephrine (PE-BRS) or sodium nitroprusside (NP-BRS) was determined by linear regression method. Cardiac sympathetic and parasympathetic influences were determined by autonomic blockades. In the saline-treated PDH rats, PE-BRS was enhanced early at week 4 and became greater at week 12. Abnormalities in NP-BRS and cardiac autonomic influences were found only after week 12. Four weeks of RSG treatment normalized blood glucose levels but not PE-BRS. All altered cardiovascular variables were completely restored by 12 weeks of RSG treatment. The correlation between BRS and blood glucose levels in saline-treated PDH rats was significant at week 12, but no correlation was found in RSG-treated rats. In conclusion, hyperglycemia, even in the prediabetic state, may play a role in BRS abnormalities. RSG treatment early in the prediabetic state may normalize BRS via cardiac autonomic modulation, besides its anti-hyperglycemic action.

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