J Korean Neurosurg Soc.  2014 Dec;56(6):488-491. 10.3340/jkns.2014.56.6.488.

Cortical Neuronal Loss after Chronic Prenatal Hypoxia: A Comparative Laboratory Study

• Chung YY
• Jeon YH
• Kim SW

• KMID: 2191139
• DOI: http://doi.org/10.3340/jkns.2014.56.6.488

Abstract

OBJECTIVE
The purpose of this study was to investigate the prenatal hypoxic effect on the fetal brain development.
METHODS
We used the guinea pig chronic placental insufficiency model to investigate the effect of hypoxia on fetal brain development. We ligated unilateral uterine artery at 30-32 days of gestation (dg : with term defined as -67 dg). At 50 dg, 60 dg, fetuses were sacrificed and assigned to either the growth-restricted (GR) or control (no ligation) group. After fixation, dissection, and sectioning of cerebral tissue from these animals, immunohistochemistry was performed with NeuN antibody, which is a mature neuronal marker in the cerebral cortex.
RESULTS
The number of NeuN-immunoreactive (IR) cells in the cerebral cortex did not differ between the GR and control groups at 50 dg. However, the number of NeuN-IR cells was lesser in GR fetuses than in controls at 60 dg (p<0.05).
CONCLUSION
These findings show that chronic prenatal hypoxia affect the number of neuron in the cerebral cortex of guinea pig fetus at 60 dg. The approach used in this study is helpful for extending our understanding of neurogenesis in the cerebral cortex, and the findings may be useful for elucidating the brain injury caused by prenatal hypoxia.

Keyword

Hypoxia; Cerebral cortex; Neuron

MeSH Terms

Animals
Anoxia*
Brain
Brain Injuries
Cerebral Cortex
Fetus
Guinea Pigs
Immunohistochemistry
Neurogenesis
Neurons*
Placental Insufficiency
Pregnancy
Uterine Artery

Figure

• 

  Fig. 1 The density of NeuN-IR cells in the cerebral cortex from controls (n=7) and GR fetuses (n=7) at 50 dg (p>0.05). Values are expressed as a mean±SEM. SEM : standard error of mean, IR : immunoreactive, GR : growth-restricted.

• 

  Fig. 2 The proportion of NeuN-IR cells in the cerebral cortex from controls (n=7) and GR fetuses (n=7) at 50 dg. The proportion did not differ between both groups (p>0.05). Values are expressed as a mean±SEM. SEM : standard error of mean, IR : immunoreactive, GR : growth-restricted.

• 

  Fig. 3 The density of NeuN-IR cells in the cerebral cortex from controls and GR fetuses at 60 dg. The density of NeuN-IR cells was decreased in GR fetuses compared to controls at 60 dg (*p<0.05). Values are expressed as a mean±SEM. SEM : standard error of mean, IR : immunoreactive, GR : growth-restricted.

• 

  Fig. 4 The proportion of NeuN-IR cells in the cerebral cortex from controls and GR fetuses at 60 dg. The proportion of NeuN-IR cells significantly differed between control and GR group (*p<0.05). Values are expressed as a mean±SEM. SEM : standard error of mean, IR : immunoreactive, GR : growth-restricted.

• 

  Fig. 5 Representative photomicrographs of the NeuN immunoreactivity in the cerebral parietal cortex from a control and a GR fetus. The density of NeuN-IR cells was decreased in GR fetuses compared to controls at 60 dg. IR : immunoreactive, GR : growth-restricted.

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