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Adaptation of Microelectrode Array Technology for the Study of Anesthesia-induced Neurotoxicity in the Intact Piglet Brain
Published on: May 12, 2018
Clinical anesthesia causes permanent damage to the fetal guinea pig brain
Sabina Rizzi1, Lisa B Carter, Carlo Ori
1Department of Anesthesiology, University of Virginia Health System, Charlottesville, VA 22908, USA.
Insights
General anesthesia can harm developing brains. This study in guinea pigs shows anesthesia causes fetal brain cell death and permanent damage, even with stable maternal health.
Area of Science:
- Neuroscience
- Anesthesiology
- Developmental Biology
Background:
- General anesthesia exposure in immature brains is common but its safety is questioned.
- Concerns exist regarding anesthetic neurotoxicity in developing mammals, with prior studies on rats facing species-specific criticisms.
- Guinea pigs offer a more relevant model due to longer, predominantly prenatal brain development, allowing fetal brain studies.
Purpose of the Study:
- To investigate the neurotoxic effects of general anesthesia on fetal brain development in guinea pigs.
- To assess whether anesthesia-induced neuroapoptosis leads to permanent neuronal loss and brain damage.
Main Methods:
- Pregnant guinea pigs were exposed to isoflurane anesthesia, alone or with nitrous oxide/midazolam, during peak fetal synaptogenesis.
- Maternal homeostasis was invasively monitored to ensure adequate physiological support.
- Fetal brains were examined postnatally for neuroapoptosis and neuronal loss in vulnerable regions.
Main Results:
- A single, short maternal exposure to isoflurane induced severe neuroapoptosis in the fetal guinea pig brain.
- This resulted in significant neuronal loss in critical brain areas detectable early postnatally.
- Anesthesia exposure led to permanent brain damage, evidenced by widespread cell death.
Conclusions:
- General anesthesia poses a risk of neurotoxicity to the developing fetal brain, even when maternal homeostasis is maintained.
- Anesthesia-induced neuroapoptosis can cause permanent neuronal loss and lasting brain damage.
- The guinea pig model demonstrates the vulnerability of the developing brain to anesthetic agents.
Abstract:
Exposure of the immature brain to general anesthesia is common. The safety of this practice has recently been challenged in view of evidence that general anesthetics can damage developing mammalian neurons. Initial reports on immature rats raised criticism regarding the possibly unique vulnerability of this species, short duration of their brain development and a lack of close monitoring of nutritional and cardiopulmonary homeostasis during anesthesia. Therefore, we studied the neurotoxic effects of anesthesia in guinea pigs, whose brain development is longer and is mostly a prenatal phenomenon, so that anesthesia-induced neurotoxicity studies of the fetal brain can be performed by anesthetizing pregnant female pigs. Because of their large size, these animals made invasive monitoring of maternal and, indirectly, fetal well-being technically feasible. Despite adequate maintenance of maternal homeostasis, a single short maternal exposure to isoflurane, whether alone or with nitrous oxide and/or midazolam at the peak of fetal synaptogenesis, induced severe neuroapoptosis in the fetal guinea pig brain. As detected early in post-natal life, this resulted in the loss of many neurons from vulnerable brain regions, demonstrating that anesthesia-induced neuroapoptosis can cause permanent brain damage.
