Document Detail


Electrocortical activity in fetal sheep in the last seven days of gestation.
MedLine Citation:
PMID:  9782177     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
1. Electrocorticogram (ECoG) and myometrial electromyogram (EMG) were recorded continuously in chronically instrumented late gestation sheep fetuses (n = 9) to analyse: (1) 24 h ECoG patterns, (2) relationships between ECoG and myometrial contractility, and (3) 24 h ECoG patterns at the spontaneous onset of labour. 2. Spontaneous onset of labour was determined from the myometrial EMG. ECoG signals were purified by a denoising procedure of wavelet decomposition. High-voltage slow ECoG activity (HV) and low-voltage fast ECoG activity (LV) were determined mathematically, and HV-LV cycle periodicity was calculated by periodogram analysis. 3. Twenty-four hour rhythms were present in fetal ECoG HV-LV cycles in the 3-5 days prior to spontaneous onset of labour (P < 0.01). Cycle frequency was lower at 08.00-12.00 h and higher at 16.00-20.00 h (lights on at 07.00 h, lights off at 21.00 h). LV duration was longer at 20.00-24.00 h, and HV was shorter at 16.00-20.00 h. No relationship was found between ECoG cycles and myometrial contracture cycles. Twenty-four hour ECoG rhythms disappeared 1 day before the spontaneous onset of labour. 4. ECoG patterns changed 7 to 4 h prior to spontaneous onset of labour, percentage of time spent and duration of HV ECoG increased, and percentage of time spent in LV decreased significantly. ECoG HV-LV cyclicity was reduced 4-5 h prior to spontaneous onset of labour, indicating that the altered fetal hormonal and blood gas environment around the spontaneous onset of labour alter fetal neural function.
Authors:
N Shinozuka; P W Nathanielsz
Related Documents :
807977 - Defibrination in obstetrics. modern concepts.
10591427 - Surfactant-deficient respiratory distress after elective delivery at 'term'.
10092917 - Antenatal hospitalisations in new south wales, 1995-96.
10796187 - Zinc supplementation in pregnancy.
23496277 - Obstetric cholestasis: outcome with active management.
25020057 - Management of high-risk pregnancy.
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  The Journal of physiology     Volume:  513 ( Pt 1)     ISSN:  0022-3751     ISO Abbreviation:  J. Physiol. (Lond.)     Publication Date:  1998 Nov 
Date Detail:
Created Date:  1999-01-29     Completed Date:  1999-01-29     Revised Date:  2013-06-11    
Medline Journal Info:
Nlm Unique ID:  0266262     Medline TA:  J Physiol     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  273-81     Citation Subset:  IM    
Affiliation:
Laboratory for Pregnancy and Newborn Research, Department of Physiology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853-6401, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Blood Gas Analysis
Blood Pressure / physiology
Central Nervous System / embryology,  physiology*
Electroencephalography*
Electromyography
Electrophysiology
Female
Fetus / physiology*
Heart Rate, Fetal / physiology
Labor, Obstetric / physiology
Myometrium / physiology
Pregnancy
Sheep
Comments/Corrections

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Reflex control of splanchnic blood volume in anaesthetized dogs.
Next Document:  The effect of dopamine on lung liquid production by in vitro lungs from fetal guinea-pigs.