Skip to main content
Top
Published in: Journal of Neuroinflammation 1/2016

Open Access 01-12-2016 | Research

Decreased neuroinflammation correlates to higher vagus nerve activity fluctuations in near-term ovine fetuses: a case for the afferent cholinergic anti-inflammatory pathway?

Authors: M. G. Frasch, M. Szynkaruk, A. P. Prout, K. Nygard, M. Cao, R. Veldhuizen, R. Hammond, B. S. Richardson

Published in: Journal of Neuroinflammation | Issue 1/2016

Login to get access

Abstract

Background

Neuroinflammation in utero may contribute to brain injury resulting in life-long neurological disabilities. The pivotal role of the efferent cholinergic anti-inflammatory pathway (CAP) in controlling inflammation, e.g., by inhibiting the HMGB1 release, via the macrophages’ α7 nicotinic acetylcholine receptor (α7nAChR) has been described in adults, but its importance in the fetus is unknown. Moreover, it is unknown whether CAP may also exert anti-inflammatory effects on the brain via the anatomically predominant afferent component of the vagus nerve.

Methods

We measured microglial activation in the ovine fetal brain near term 24 h after the umbilical cord occlusions mimicking human labor versus controls (no occlusions) by quantifying HMGB1 nucleus-to-cytosol translocation in the Iba1+ and α7nAChR+ microglia. Based on multiple clinical studies in adults and our own work in fetal autonomic nervous system, we gauged the degree of CAP activity in vivo using heart rate variability measure RMSSD that reflects fluctuations in vagus nerve activity.

Results

RMSSD correlated to corresponding plasma IL-1β levels at R = 0.57 (p = 0.02, n = 17) and to white matter microglia cell counts at R = −0.89 (p = 0.03). The insult increased the HMGB1 translocation in α7nAChR+ microglia in a brain region-dependent manner (p < 0.001). In parallel, RMSSD at 1 h post insult correlated with cytosolic HMGB1 of thalamic microglia (R = −0.94, p = 0.005), and RMSSD at pH nadir correlated with microglial α7nAChR in the white matter (R = 0.83, p = 0.04). Overall, higher RMSSD values correlated with lower HMGB1 translocation and higher α7nAChR intensity per area in a brain region-specific manner.

Conclusions

Afferent fetal CAP may translate increased vagal cholinergic signaling into suppression of cerebral inflammation in response to near-term hypoxic acidemia as might occur during labor. Our findings suggest a new control mechanism of fetal neuroinflammation via the vagus nerve, providing novel possibilities for its non-invasive monitoring in utero and for targeted treatment.
Appendix
Available only for authorised users
Literature
2.
go back to reference Frasch MG, Muller T, Wicher C, Weiss C, Lohle M, Schwab K, et al. Fetal body weight and the development of the control of the cardiovascular system in fetal sheep. J Physiol. 2007;579(Pt 3):893–907.CrossRefPubMedPubMedCentral Frasch MG, Muller T, Wicher C, Weiss C, Lohle M, Schwab K, et al. Fetal body weight and the development of the control of the cardiovascular system in fetal sheep. J Physiol. 2007;579(Pt 3):893–907.CrossRefPubMedPubMedCentral
3.
go back to reference Sloan RP, McCreath H, Tracey KJ, Sidney S, Liu K, Seeman T. RR interval variability is inversely related to inflammatory markers: the CARDIA study. Mol Med (Cambridge, Mass). 2007;13(3-4):178–84. Sloan RP, McCreath H, Tracey KJ, Sidney S, Liu K, Seeman T. RR interval variability is inversely related to inflammatory markers: the CARDIA study. Mol Med (Cambridge, Mass). 2007;13(3-4):178–84.
4.
go back to reference Frasch MG, Mueller T, Weiss C, Schwab K, Schubert H, Schwab M. Heart Rate Variability Analysis Allows Early Asphyxia Detection in Ovine Fetus. Reproductive sciences (Thousand Oaks, Calif). 2009;16(5):509-17. doi:10.1177/1933719108327597. Frasch MG, Mueller T, Weiss C, Schwab K, Schubert H, Schwab M. Heart Rate Variability Analysis Allows Early Asphyxia Detection in Ovine Fetus. Reproductive sciences (Thousand Oaks, Calif). 2009;16(5):509-17. doi:10.​1177/​1933719108327597​.
6.
go back to reference Shytle RD, Mori T, Townsend K, Vendrame M, Sun N, Zeng J, et al. Cholinergic modulation of microglial activation by alpha 7 nicotinic receptors. J Neurochem. 2004;89(2):337–43.CrossRefPubMed Shytle RD, Mori T, Townsend K, Vendrame M, Sun N, Zeng J, et al. Cholinergic modulation of microglial activation by alpha 7 nicotinic receptors. J Neurochem. 2004;89(2):337–43.CrossRefPubMed
7.
go back to reference Hua S, Ek CJ, Mallard C, Johansson ME. Perinatal hypoxia-ischemia reduces alpha 7 nicotinic receptor expression and selective alpha 7 nicotinic receptor stimulation suppresses inflammation and promotes microglial Mox phenotype. BioMed Res Int. 2014;2014:718769.PubMedPubMedCentral Hua S, Ek CJ, Mallard C, Johansson ME. Perinatal hypoxia-ischemia reduces alpha 7 nicotinic receptor expression and selective alpha 7 nicotinic receptor stimulation suppresses inflammation and promotes microglial Mox phenotype. BioMed Res Int. 2014;2014:718769.PubMedPubMedCentral
8.
go back to reference Suzuki T, Hide I, Matsubara A, Hama C, Harada K, Miyano K, et al. Microglial alpha7 nicotinic acetylcholine receptors drive a phospholipase C/IP3 pathway and modulate the cell activation toward a neuroprotective role. J Neurosci Res. 2006;83(8):1461–70.CrossRefPubMed Suzuki T, Hide I, Matsubara A, Hama C, Harada K, Miyano K, et al. Microglial alpha7 nicotinic acetylcholine receptors drive a phospholipase C/IP3 pathway and modulate the cell activation toward a neuroprotective role. J Neurosci Res. 2006;83(8):1461–70.CrossRefPubMed
9.
go back to reference Kim JB, Lim CM, Yu YM, Lee JK. Induction and subcellular localization of high-mobility group box-1 (HMGB1) in the postischemic rat brain. J Neurosci Res. 2008;86(5):1125–31.CrossRefPubMed Kim JB, Lim CM, Yu YM, Lee JK. Induction and subcellular localization of high-mobility group box-1 (HMGB1) in the postischemic rat brain. J Neurosci Res. 2008;86(5):1125–31.CrossRefPubMed
10.
go back to reference Wang H, Liao H, Ochani M, Justiniani M, Lin X, Yang L, et al. Cholinergic agonists inhibit HMGB1 release and improve survival in experimental sepsis. Nat Med. 2004;10(11):1216–21.CrossRefPubMed Wang H, Liao H, Ochani M, Justiniani M, Lin X, Yang L, et al. Cholinergic agonists inhibit HMGB1 release and improve survival in experimental sepsis. Nat Med. 2004;10(11):1216–21.CrossRefPubMed
11.
go back to reference Yang QW, Wang JZ, Li JC, Zhou Y, Zhong Q, Lu FL, et al. High-mobility group protein box-1 and its relevance to cerebral ischemia. J Cereb Blood Flow Metab. 2010;30(2):243–54.CrossRefPubMedPubMedCentral Yang QW, Wang JZ, Li JC, Zhou Y, Zhong Q, Lu FL, et al. High-mobility group protein box-1 and its relevance to cerebral ischemia. J Cereb Blood Flow Metab. 2010;30(2):243–54.CrossRefPubMedPubMedCentral
12.
go back to reference Green LR, Kawagoe Y, Homan J, White SE, Richardson BS. Adaptation of cardiovascular responses to repetitive umbilical cord occlusion in the late gestation ovine fetus. J Physiol. 2001;535(Pt 3):879–88.CrossRefPubMedPubMedCentral Green LR, Kawagoe Y, Homan J, White SE, Richardson BS. Adaptation of cardiovascular responses to repetitive umbilical cord occlusion in the late gestation ovine fetus. J Physiol. 2001;535(Pt 3):879–88.CrossRefPubMedPubMedCentral
13.
go back to reference Rees S, Inder T. Fetal and neonatal origins of altered brain development. Early Hum Dev. 2005;81(9):753–61.CrossRefPubMed Rees S, Inder T. Fetal and neonatal origins of altered brain development. Early Hum Dev. 2005;81(9):753–61.CrossRefPubMed
14.
go back to reference Van Leeuwen P, Lange S, Bettermann H, Gronemeyer D, Hatzmann W. Fetal heart rate variability and complexity in the course of pregnancy. Early Hum Dev. 1999;54(3):259–69.CrossRefPubMed Van Leeuwen P, Lange S, Bettermann H, Gronemeyer D, Hatzmann W. Fetal heart rate variability and complexity in the course of pregnancy. Early Hum Dev. 1999;54(3):259–69.CrossRefPubMed
15.
go back to reference Frasch M, Prout A, Szynkaruk M, Gagnon R, Richardson B. Cholinergic anti-inflammatory pathway mechanisms may be active in the pre-term ovine fetus. Reprod Sci. 2009;16(3 (Suppl)):137A. Frasch M, Prout A, Szynkaruk M, Gagnon R, Richardson B. Cholinergic anti-inflammatory pathway mechanisms may be active in the pre-term ovine fetus. Reprod Sci. 2009;16(3 (Suppl)):137A.
16.
go back to reference Frasch MG, Mansano RZ, Gagnon R, Richardson BS, Ross MG. Measures of acidosis with repetitive umbilical cord occlusions leading to fetal asphyxia in the near-term ovine fetus. Am J Obstet Gynecol. 2009;200(27):200.e1-7.PubMed Frasch MG, Mansano RZ, Gagnon R, Richardson BS, Ross MG. Measures of acidosis with repetitive umbilical cord occlusions leading to fetal asphyxia in the near-term ovine fetus. Am J Obstet Gynecol. 2009;200(27):200.e1-7.PubMed
17.
go back to reference Prout AP, Frasch MG, Veldhuizen RA, Hammond R, Ross MG, Richardson BS. Systemic and cerebral inflammatory response to umbilical cord occlusions with worsening acidosis in the ovine fetus. Am J Obstet Gynecol. 2010;202(1):82 e1-9.CrossRefPubMed Prout AP, Frasch MG, Veldhuizen RA, Hammond R, Ross MG, Richardson BS. Systemic and cerebral inflammatory response to umbilical cord occlusions with worsening acidosis in the ovine fetus. Am J Obstet Gynecol. 2010;202(1):82 e1-9.CrossRefPubMed
18.
go back to reference Prout AP, Frasch MG, Veldhuizen R, Hammond R, Matuishewski B, Richardson BS. The impact of intermittent umbilical cord occlusions on the inflammatory response in pre-term fetal sheep. PLoS One. 2012;7(6):e39043.CrossRefPubMedPubMedCentral Prout AP, Frasch MG, Veldhuizen R, Hammond R, Matuishewski B, Richardson BS. The impact of intermittent umbilical cord occlusions on the inflammatory response in pre-term fetal sheep. PLoS One. 2012;7(6):e39043.CrossRefPubMedPubMedCentral
19.
go back to reference Rutecki P. Anatomical, physiological, and theoretical basis for the antiepileptic effect of vagus nerve stimulation. Epilepsia. 1990;31 Suppl 2:S1–6.CrossRefPubMed Rutecki P. Anatomical, physiological, and theoretical basis for the antiepileptic effect of vagus nerve stimulation. Epilepsia. 1990;31 Suppl 2:S1–6.CrossRefPubMed
20.
go back to reference Gallaher ZR, Ryu V, Herzog T, Ritter RC, Czaja K. Changes in microglial activation within the hindbrain, nodose ganglia, and the spinal cord following subdiaphragmatic vagotomy. Neurosci Lett. 2012;513(1):31–6.CrossRefPubMedPubMedCentral Gallaher ZR, Ryu V, Herzog T, Ritter RC, Czaja K. Changes in microglial activation within the hindbrain, nodose ganglia, and the spinal cord following subdiaphragmatic vagotomy. Neurosci Lett. 2012;513(1):31–6.CrossRefPubMedPubMedCentral
23.
go back to reference Hess A, Axmann R, Rech J, Finzel S, Heindl C, Kreitz S, et al. Blockade of TNF-alpha rapidly inhibits pain responses in the central nervous system. Proc Natl Acad Sci U S A. 2011;108(9):3731–6.CrossRefPubMedPubMedCentral Hess A, Axmann R, Rech J, Finzel S, Heindl C, Kreitz S, et al. Blockade of TNF-alpha rapidly inhibits pain responses in the central nervous system. Proc Natl Acad Sci U S A. 2011;108(9):3731–6.CrossRefPubMedPubMedCentral
24.
go back to reference Bond CE, Zimmermann M, Greenfield SA. Upregulation of alpha7 nicotinic receptors by acetylcholinesterase C-terminal peptides. PLoS One. 2009;4(3):e4846.CrossRefPubMedPubMedCentral Bond CE, Zimmermann M, Greenfield SA. Upregulation of alpha7 nicotinic receptors by acetylcholinesterase C-terminal peptides. PLoS One. 2009;4(3):e4846.CrossRefPubMedPubMedCentral
25.
go back to reference Li X, Han X, Bao J, Liu Y, Ye A, Thakur M, Liu H. Nicotine increases eclampsia-like seizure threshold and attenuates microglial activity in rat hippocampus through the α7 nicotinic acetylcholine receptor. Brain Res. 2016. doi: 10.1016/j.brainres.2016.04.043. [Epub ahead of print]. Li X, Han X, Bao J, Liu Y, Ye A, Thakur M, Liu H. Nicotine increases eclampsia-like seizure threshold and attenuates microglial activity in rat hippocampus through the α7 nicotinic acetylcholine receptor. Brain Res. 2016. doi: 10.​1016/​j.​brainres.​2016.​04.​043. [Epub ahead of print].
26.
go back to reference De Simone R, Ajmone-Cat MA, Carnevale D, Minghetti L. Activation of alpha7 nicotinic acetylcholine receptor by nicotine selectively up-regulates cyclooxygenase-2 and prostaglandin E2 in rat microglial cultures. J Neuroinflammation. 2005;2(1):4.CrossRefPubMedPubMedCentral De Simone R, Ajmone-Cat MA, Carnevale D, Minghetti L. Activation of alpha7 nicotinic acetylcholine receptor by nicotine selectively up-regulates cyclooxygenase-2 and prostaglandin E2 in rat microglial cultures. J Neuroinflammation. 2005;2(1):4.CrossRefPubMedPubMedCentral
27.
go back to reference Kaneko M, White S, Homan J, Richardson B. Cerebral blood flow and metabolism in relation to electrocortical activity with severe umbilical cord occlusion in the near-term ovine fetus. Am J Obstet Gynecol. 2003;188(4):961–72.CrossRefPubMed Kaneko M, White S, Homan J, Richardson B. Cerebral blood flow and metabolism in relation to electrocortical activity with severe umbilical cord occlusion in the near-term ovine fetus. Am J Obstet Gynecol. 2003;188(4):961–72.CrossRefPubMed
28.
go back to reference Xu A, Durosier LD, Ross MG, Hammond R, Richardson BS, Frasch MG. Adaptive brain shut-down counteracts neuroinflammation in the near-term ovine fetus. Front Neurol. 2014;5:110.CrossRefPubMedPubMedCentral Xu A, Durosier LD, Ross MG, Hammond R, Richardson BS, Frasch MG. Adaptive brain shut-down counteracts neuroinflammation in the near-term ovine fetus. Front Neurol. 2014;5:110.CrossRefPubMedPubMedCentral
29.
31.
go back to reference Fairchild KD, Srinivasan V, Moorman JR, Gaykema RP, Goehler LE. Pathogen-induced heart rate changes associated with cholinergic nervous system activation. Am J Physiol Regul Integr Comp Physiol. 2011;300(2):R330–9.CrossRefPubMedPubMedCentral Fairchild KD, Srinivasan V, Moorman JR, Gaykema RP, Goehler LE. Pathogen-induced heart rate changes associated with cholinergic nervous system activation. Am J Physiol Regul Integr Comp Physiol. 2011;300(2):R330–9.CrossRefPubMedPubMedCentral
32.
go back to reference Vellucci SV, Parrott RF. Expression of c-fos in the ovine brain following different types of stress, or central administration of corticotrophin-releasing hormone. Exp Physiol. 1994;79(2):241.CrossRefPubMed Vellucci SV, Parrott RF. Expression of c-fos in the ovine brain following different types of stress, or central administration of corticotrophin-releasing hormone. Exp Physiol. 1994;79(2):241.CrossRefPubMed
33.
go back to reference Bokesch PM, Seirafi PA, Warner KG, Marchand JE, Kream RM, Trapp B. Differential immediate-early gene expression in ovine brain after cardiopulmonary bypass and hypothermic circulatory arrest. Anesthesiology. 1998;89(4):961–8.CrossRefPubMed Bokesch PM, Seirafi PA, Warner KG, Marchand JE, Kream RM, Trapp B. Differential immediate-early gene expression in ovine brain after cardiopulmonary bypass and hypothermic circulatory arrest. Anesthesiology. 1998;89(4):961–8.CrossRefPubMed
34.
go back to reference Prout A, Frasch MG, Veldhuizen R, Hammond R, Ross MG, Richardson BS. Inflammatory response to repetitive umbilical cord occlusions with worsening acidosis in the near term ovine fetus. Am J Obstet Gynecol. 2009;202(1):82.e1-.CrossRef Prout A, Frasch MG, Veldhuizen R, Hammond R, Ross MG, Richardson BS. Inflammatory response to repetitive umbilical cord occlusions with worsening acidosis in the near term ovine fetus. Am J Obstet Gynecol. 2009;202(1):82.e1-.CrossRef
35.
go back to reference Frasch MG. Fetal heart rate variability monitoring. Montebello Round Table. Complexity and Variability at the Bedside. September 28 - October 1. Montebello, QC, Canada. J Crit Care. 2011;26(3):325–7.CrossRefPubMed Frasch MG. Fetal heart rate variability monitoring. Montebello Round Table. Complexity and Variability at the Bedside. September 28 - October 1. Montebello, QC, Canada. J Crit Care. 2011;26(3):325–7.CrossRefPubMed
36.
go back to reference Wang X, Rousset CI, Hagberg H, Mallard C. Lipopolysaccharide-induced inflammation and perinatal brain injury. Semin Fetal Neonatal Med. 2006;11(5):343–53.CrossRefPubMed Wang X, Rousset CI, Hagberg H, Mallard C. Lipopolysaccharide-induced inflammation and perinatal brain injury. Semin Fetal Neonatal Med. 2006;11(5):343–53.CrossRefPubMed
37.
go back to reference Goldaber KG, Gilstrap 3rd LC, Leveno KJ, Dax JS, McIntire DD. Pathologic fetal acidemia. Obstet Gynecol. 1991;78(6):1103–7.PubMed Goldaber KG, Gilstrap 3rd LC, Leveno KJ, Dax JS, McIntire DD. Pathologic fetal acidemia. Obstet Gynecol. 1991;78(6):1103–7.PubMed
38.
go back to reference DuPont TL, Chalak LF, Morriss MC, Burchfield PJ, Christie L, Sanchez PJ. Short-term outcomes of newborns with perinatal acidemia who are not eligible for systemic hypothermia therapy. J Pediatr. 2013;162(1):35–41.CrossRefPubMedPubMedCentral DuPont TL, Chalak LF, Morriss MC, Burchfield PJ, Christie L, Sanchez PJ. Short-term outcomes of newborns with perinatal acidemia who are not eligible for systemic hypothermia therapy. J Pediatr. 2013;162(1):35–41.CrossRefPubMedPubMedCentral
39.
go back to reference Shevell MI. The "Bermuda triangle" of neonatal neurology: cerebral palsy, neonatal encephalopathy, and intrapartum asphyxia. Semin Pediatr Neurol. 2004;11(1):24–30.CrossRefPubMed Shevell MI. The "Bermuda triangle" of neonatal neurology: cerebral palsy, neonatal encephalopathy, and intrapartum asphyxia. Semin Pediatr Neurol. 2004;11(1):24–30.CrossRefPubMed
40.
go back to reference Graham EM, Ruis KA, Hartman AL, Northington FJ, Fox HE. A systematic review of the role of intrapartum hypoxia-ischemia in the causation of neonatal encephalopathy. Am J Obstet Gynecol. 2008;199(6):587–95.CrossRefPubMed Graham EM, Ruis KA, Hartman AL, Northington FJ, Fox HE. A systematic review of the role of intrapartum hypoxia-ischemia in the causation of neonatal encephalopathy. Am J Obstet Gynecol. 2008;199(6):587–95.CrossRefPubMed
41.
go back to reference Low JA. Intrapartum fetal asphyxia: definition, diagnosis, and classification. Am J Obstet Gynecol. 1997;176(5):957–9.CrossRefPubMed Low JA. Intrapartum fetal asphyxia: definition, diagnosis, and classification. Am J Obstet Gynecol. 1997;176(5):957–9.CrossRefPubMed
42.
go back to reference McIntyre S, Blair E, Badawi N, Keogh J, Nelson KB. Antecedents of cerebral palsy and perinatal death in term and late preterm singletons. Obstet Gynecol. 2013;122(4):869–77.CrossRefPubMed McIntyre S, Blair E, Badawi N, Keogh J, Nelson KB. Antecedents of cerebral palsy and perinatal death in term and late preterm singletons. Obstet Gynecol. 2013;122(4):869–77.CrossRefPubMed
43.
go back to reference Gotsch F, Romero R, Kusanovic JP, Mazaki-Tovi S, Pineles BL, Erez O, et al. The fetal inflammatory response syndrome. Clin Obstet Gynecol. 2007;50(3):652–83.CrossRefPubMed Gotsch F, Romero R, Kusanovic JP, Mazaki-Tovi S, Pineles BL, Erez O, et al. The fetal inflammatory response syndrome. Clin Obstet Gynecol. 2007;50(3):652–83.CrossRefPubMed
44.
go back to reference Saigal S, Doyle LW. An overview of mortality and sequelae of preterm birth from infancy to adulthood. Lancet. 2008;371(9608):261–9.CrossRefPubMed Saigal S, Doyle LW. An overview of mortality and sequelae of preterm birth from infancy to adulthood. Lancet. 2008;371(9608):261–9.CrossRefPubMed
45.
go back to reference Durosier LD, Herry CL, Cortes M, Cao M, Burns P, Desrochers A, et al. Does heart rate variability reflect the systemic inflammatory response in a fetal sheep model of lipopolysaccharide-induced sepsis? Physiol Meas. 2015;36(10):2089–102.CrossRefPubMed Durosier LD, Herry CL, Cortes M, Cao M, Burns P, Desrochers A, et al. Does heart rate variability reflect the systemic inflammatory response in a fetal sheep model of lipopolysaccharide-induced sepsis? Physiol Meas. 2015;36(10):2089–102.CrossRefPubMed
46.
go back to reference Liu HL, Garzoni L, Herry C, Durosier LD, Cao M, Burns P, et al. Can monitoring fetal intestinal inflammation using heart rate variability analysis signal incipient necrotizing enterocolitis of the neonate? Pediatr Crit Care Med. 2016;17(4):e165–76.CrossRefPubMed Liu HL, Garzoni L, Herry C, Durosier LD, Cao M, Burns P, et al. Can monitoring fetal intestinal inflammation using heart rate variability analysis signal incipient necrotizing enterocolitis of the neonate? Pediatr Crit Care Med. 2016;17(4):e165–76.CrossRefPubMed
47.
go back to reference Frasch MG, Xu Y, Stampalija T, Durosier LD, Herry C, Wang X, et al. Correlating multidimensional fetal heart rate variability analysis with acid-base balance at birth. Physiol Meas. 2014;35(12):L1–L12.CrossRefPubMed Frasch MG, Xu Y, Stampalija T, Durosier LD, Herry C, Wang X, et al. Correlating multidimensional fetal heart rate variability analysis with acid-base balance at birth. Physiol Meas. 2014;35(12):L1–L12.CrossRefPubMed
48.
go back to reference Li X, Xu Y, Herry C, Durosier LD, Casati D, Stampalija T, et al. Sampling frequency of fetal heart rate impacts the ability to predict pH and BE at birth: a retrospective multi-cohort study. Physiol Meas. 2015;36(5):L1–L12.CrossRefPubMed Li X, Xu Y, Herry C, Durosier LD, Casati D, Stampalija T, et al. Sampling frequency of fetal heart rate impacts the ability to predict pH and BE at birth: a retrospective multi-cohort study. Physiol Meas. 2015;36(5):L1–L12.CrossRefPubMed
49.
go back to reference Rocha E, Hammond R, Richardson B. Necrotic cell injury in the preterm and near-term ovine fetal brain after intermittent umbilical cord occlusion. Am J Obstet Gynecol. 2004;191(2):488–96.CrossRefPubMed Rocha E, Hammond R, Richardson B. Necrotic cell injury in the preterm and near-term ovine fetal brain after intermittent umbilical cord occlusion. Am J Obstet Gynecol. 2004;191(2):488–96.CrossRefPubMed
50.
go back to reference Frasch MG, Keen AE, Gagnon R, Ross MG, Richardson BS. Monitoring fetal electrocortical activity during labour for predicting worsening acidemia: a prospective study in the ovine fetus near term. PLoS One. 2011;6(7):e22100.CrossRefPubMedPubMedCentral Frasch MG, Keen AE, Gagnon R, Ross MG, Richardson BS. Monitoring fetal electrocortical activity during labour for predicting worsening acidemia: a prospective study in the ovine fetus near term. PLoS One. 2011;6(7):e22100.CrossRefPubMedPubMedCentral
51.
go back to reference Cao M, Cortes M, Moore CS, Leong SY, Durosier LD, Burns P, et al. Fetal microglial phenotype in vitro carries memory of prior in vivo exposure to inflammation. Front Cell Neurosci. 2015;9:294.CrossRefPubMedPubMedCentral Cao M, Cortes M, Moore CS, Leong SY, Durosier LD, Burns P, et al. Fetal microglial phenotype in vitro carries memory of prior in vivo exposure to inflammation. Front Cell Neurosci. 2015;9:294.CrossRefPubMedPubMedCentral
52.
go back to reference Borovikova LV, Ivanova S, Zhang M, Yang H, Botchkina GI, Watkins LR, et al. Vagus nerve stimulation attenuates the systemic inflammatory response to endotoxin. Nature. 2000;405(6785):458–62.CrossRefPubMed Borovikova LV, Ivanova S, Zhang M, Yang H, Botchkina GI, Watkins LR, et al. Vagus nerve stimulation attenuates the systemic inflammatory response to endotoxin. Nature. 2000;405(6785):458–62.CrossRefPubMed
53.
go back to reference Tavakol S, Kwan H, Jean K, Cao M, Burns P, Desrochers A, et al. Fetal vagal cholinergic activity modulates inflammatory and cardiovascular responses to low-dose endotoxin exposure. Society for Reproductive Investigation. Montreal: Reproductive Sciences; 2016. p. 228A. Tavakol S, Kwan H, Jean K, Cao M, Burns P, Desrochers A, et al. Fetal vagal cholinergic activity modulates inflammatory and cardiovascular responses to low-dose endotoxin exposure. Society for Reproductive Investigation. Montreal: Reproductive Sciences; 2016. p. 228A.
54.
go back to reference Frasch MG, Muller T, Weiss C, Schwab K, Schubert H, Schwab M. Heart rate variability analysis allows early asphyxia detection in ovine fetus. Reprod Sci (Thousand Oaks, Calif). 2009;16(5):509–17.CrossRef Frasch MG, Muller T, Weiss C, Schwab K, Schubert H, Schwab M. Heart rate variability analysis allows early asphyxia detection in ovine fetus. Reprod Sci (Thousand Oaks, Calif). 2009;16(5):509–17.CrossRef
55.
go back to reference McElwain JW, Alexander RM, MacLean MD. The management of functional constipation in infants and children. Med Times. 1969;97(5):174–6.PubMed McElwain JW, Alexander RM, MacLean MD. The management of functional constipation in infants and children. Med Times. 1969;97(5):174–6.PubMed
Metadata
Title
Decreased neuroinflammation correlates to higher vagus nerve activity fluctuations in near-term ovine fetuses: a case for the afferent cholinergic anti-inflammatory pathway?
Authors
M. G. Frasch
M. Szynkaruk
A. P. Prout
K. Nygard
M. Cao
R. Veldhuizen
R. Hammond
B. S. Richardson
Publication date
01-12-2016
Publisher
BioMed Central
Published in
Journal of Neuroinflammation / Issue 1/2016
Electronic ISSN: 1742-2094
DOI
https://doi.org/10.1186/s12974-016-0567-x

Other articles of this Issue 1/2016

Journal of Neuroinflammation 1/2016 Go to the issue