Skip to main content
NCBI home page
The Journal of Physiology logoLink to The Journal of Physiology
. 1983 Aug;341:463–476. doi: 10.1113/jphysiol.1983.sp014817

Changes in breathing, electrocortical and muscle activity in unanaesthetized fetal lambs with age.

F Clewlow, G S Dawes, B M Johnston, D W Walker
PMCID: PMC1195345  PMID: 6413680

Abstract

Electrocortical and electro-ocular activity, breathing movements and nuchal muscle activity were recorded continuously in the unanaesthetized lamb in utero (95-135 days). Electrocortical activity was recorded simultaneously from various sites. The bi-parietal electrocorticogram gave the clearest differentiation between high- and low-voltage activity. The onset of cortical differentiation from 110 days gestation was attributed to the superimposition of high-voltage electrocortical activity at 3-10 Hz on existing low-voltage activity. Three distinct patterns in the relationships between electrocortical activity, ocular activity breathing movements and nuchal muscle activity were observed at 95-106, 107-114 and 120-135 days. Isocapnic hypoxia caused a diminution in fetal breathing from 95-135 days gestation, quantitatively greater near term. After cortical differentiation, hypoxia caused the appearance of high-voltage activity within 4 min, if low-voltage electrocortical activity was present initially. The relationship, changing with age, between electrocortical activity, breathing movements, ocular and nuchal muscle activity is discussed.

Full text

PDF
463

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Blanco C. E., Dawes G. S., Walker D. W. Effects of hypoxia on polysynaptic hind-limb reflexes in new-born lambs before and after carotid denervation. J Physiol. 1983 Jun;339:467–474. doi: 10.1113/jphysiol.1983.sp014727. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bloom S. R., Edwards A. V., Järhult J. The effect of somatostatin on pancreatic endocrine responses mediated via the parasympathetic innervation in the conscious calf. J Physiol. 1980 Nov;308:29–38. doi: 10.1113/jphysiol.1980.sp013459. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Boddy K., Dawes G. S., Fisher R., Pinter S., Robinson J. S. Foetal respiratory movements, electrocortical and cardiovascular responses to hypoxaemia and hypercapnia in sheep. J Physiol. 1974 Dec;243(3):599–618. doi: 10.1113/jphysiol.1974.sp010768. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Bowes G., Adamson T. M., Ritchie B. C., Dowling M., Wilkinson M. H., Maloney J. E. Development of patterns of respiratory activity in unanesthetized fetal sheep in utero. J Appl Physiol Respir Environ Exerc Physiol. 1981 Apr;50(4):693–700. doi: 10.1152/jappl.1981.50.4.693. [DOI] [PubMed] [Google Scholar]
  5. Bowes G., Wilkinson M. H., Dowling M., Ritchie B. C., Brodecky V., Maloney J. E. Hypercapnic stimulation of respiratory activity in unanesthetized fetal sheep in utero. J Appl Physiol Respir Environ Exerc Physiol. 1981 Apr;50(4):701–708. doi: 10.1152/jappl.1981.50.4.701. [DOI] [PubMed] [Google Scholar]
  6. Chapman R. L., Dawes G. S., Rurak D. W., Wilds P. L. Intermittent breathing before death in fetal lambs. Am J Obstet Gynecol. 1978 Aug 15;131(8):894–898. doi: 10.1016/s0002-9378(16)33138-6. [DOI] [PubMed] [Google Scholar]
  7. Dawes G. S., Fox H. E., Leduc B. M., Liggins G. C., Richards R. T. Respiratory movements and rapid eye movement sleep in the foetal lamb. J Physiol. 1972 Jan;220(1):119–143. doi: 10.1113/jphysiol.1972.sp009698. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Dawes G. S., Gardner W. N., Johnston B. M., Walker D. W. Breathing in fetal lambs: the effect of brain stem section. J Physiol. 1983 Feb;335:535–553. doi: 10.1113/jphysiol.1983.sp014549. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Dawes G. S., Gardner W. N., Johnston B. M., Walker D. W. Effects of hypercapnia on tracheal pressure, diaphragm and intercostal electromyograms in unanaesthetized fetal lambs. J Physiol. 1982 May;326:461–474. doi: 10.1113/jphysiol.1982.sp014206. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Henderson-Smart D. J., Read D. J. Reduced lung volume during behavioral active sleep in the newborn. J Appl Physiol Respir Environ Exerc Physiol. 1979 Jun;46(6):1081–1085. doi: 10.1152/jappl.1979.46.6.1081. [DOI] [PubMed] [Google Scholar]
  11. Jost R. G., Quilligan E. J., Yeh S. Y., Anderson G. G. Intrauterine electroencephalogram of the sheep fetus. Am J Obstet Gynecol. 1972 Oct 15;114(4):535–539. doi: 10.1016/0002-9378(72)90216-5. [DOI] [PubMed] [Google Scholar]
  12. Jouvet-Mounier D., Astic L., Lacote D. Ontogenesis of the states of sleep in rat, cat, and guinea pig during the first postnatal month. Dev Psychobiol. 1970;2(4):216–239. doi: 10.1002/dev.420020407. [DOI] [PubMed] [Google Scholar]
  13. Kitterman J. A., Liggins G. C., Clements J. A., Tooley W. H. Stimulation of breathing movements in fetal sheep by inhibitors of prostaglandin synthesis. J Dev Physiol. 1979 Dec;1(6):453–466. [PubMed] [Google Scholar]
  14. Natale R., Clewlow F., Dawes G. S. Measurement of fetal forelimb movements in the lamb in utero. Am J Obstet Gynecol. 1981 Jul 1;140(5):545–551. doi: 10.1016/0002-9378(81)90231-3. [DOI] [PubMed] [Google Scholar]
  15. Pappenheimer J. R. Sleep and respiration of rats during hypoxia. J Physiol. 1977 Mar;266(1):191–207. doi: 10.1113/jphysiol.1977.sp011763. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Quilligan E. J., Clewlow F., Johnston B. M., Walker D. W. Effect of 5-hydroxytryptophan on electrocortical activity and breathing movements of fetal sheep. Am J Obstet Gynecol. 1981 Oct 1;141(3):271–275. doi: 10.1016/s0002-9378(16)32632-1. [DOI] [PubMed] [Google Scholar]
  17. Rigatto H., Blanco C. E., Walker D. W. The response to stimulation of hindlimb nerves in fetal sheep, in utero, during the different phases of electrocortical activity. J Dev Physiol. 1982 Jun;4(3):175–185. [PubMed] [Google Scholar]
  18. Robinson J. S., Kingston E. J., Thorburn G. D. Increased fetal breathing activity after fetal hypophysectomy. Am J Obstet Gynecol. 1980 Jul 15;137(6):729–734. doi: 10.1016/s0002-9378(15)33250-6. [DOI] [PubMed] [Google Scholar]
  19. Ruckebusch Y., Gaujoux M., Eghbali B. Sleep cycles and kinesis in the foetal lamb. Electroencephalogr Clin Neurophysiol. 1977 Feb;42(2):226–237. doi: 10.1016/0013-4694(77)90029-3. [DOI] [PubMed] [Google Scholar]

Articles from The Journal of Physiology are provided here courtesy of The Physiological Society

RESOURCES