Posts tagged fetal brain
Articles and news from the latest research reports.
Fetal Neuromaturation Associated with Mother’s Exposure to DDT and Other Environmental Contaminants
Study is the first to show association between mother’s chemical exposure and fetal motor activity and heart rate
A study led by researchers at the Johns Hopkins Bloomberg School of Public Health has for the first time found that a mother’s higher exposure to some common environmental contaminants was associated with more frequent and vigorous fetal motor activity. Some chemicals were also associated with fewer changes in fetal heart rate, which normally parallel fetal movements. The study of 50 pregnant women found detectable levels of organochlorines in all of the women participating in the study—including DDT, PCBs and other pesticides that have been banned from use for more than 30 years. The study is available online in advance of publication in the Journal of Exposure Science and Environmental Epidemiology.
“Both fetal motor activity and heart rate reveal how the fetus is maturing and give us a way to evaluate how exposures may be affecting the developing nervous system. Most studies of environmental contaminants and child development wait until children are much older to evaluate effects of things the mother may have been exposed to during pregnancy; here we have observed effects in utero,” said Janet A. DiPietro, PhD, lead author of the study and Associate Dean for Research at the Bloomberg School of Public Health.
For the study, DiPietro and her colleagues followed a sample of 50 high- and low- income pregnant women living in and around Baltimore, Md. At 36 weeks of pregnancy, blood samples were collected from the mothers and measurements were taken of fetal heart rate and motor activity. The blood samples were tested for levels of 11 pesticides and 36 polychlorinated biphenyl (PCB) compounds.
According to the findings, all participants had detectable concentrations of at least one-quarter of the analyzed chemicals, despite the fact that they have been banned for more than three decades. Fetal heart rate effects were not consistently observed across all of the compounds analyzed; when effects were seen, higher chemical exposures were associated with reductions in fetal heart rate accelerations, an indicator of fetal wellbeing. However, associations with fetal motor activity measures were more consistent and robust: higher concentrations of 7 of 10 organochlorine compounds were positively associated with one of more measures of more frequent and more vigorous fetal motor activity. These chemicals included hexachlorobenzene, DDT, and several PCB congeners. Women of higher socioeconomic status in the study had a greater concentration of chemicals compared to the women of lower socioeconomic status
“There is tremendous interest in how the prenatal period sets the stage for later child development. These results show that the developing fetus is susceptible to environmental exposures and that we can detect this by measuring fetal neurobehavior. This is yet more evidence for the need to protect the vulnerable developing brain from effects of environmental contaminants both before and after birth,” said DiPietro.
“Fetal heart rate and motor activity associations with maternal organochlorine levels: results of an exploratory study” was written by Janet A. DiPietro, Meghan F. Davis, Kathleen A. Costigan, and Dana Boyd Barr.
(Source: jhsph.edu)
London neuroscience centre to map ‘connectome’ of foetal brain
A state-of-the-art imaging facility at St Thomas’ Hospital in London has been awarded a 15m euro grant to map the development of nerve connections in the brain before and just after birth.
The Centre for the Developing Brain — which is partly funded by King’s College London (KCL) — has built a unique neonatal Magnetic Resonance Imaging Clinical Research Facility based in the intensive care unit of the Evelina Children’s Hospital at St Thomas’. It is one of two centres in the world — the other being at Imperial College — to have such a clinical research facility and associated scanner within a neonatal intensive care unit.
Over the next few years a team headed up by David Edwards, a consultant neonatologist and KCL Professor of Paediatrics and Neonatal Medicine, will build up a diagram of connections in the brain of babies as they develop in the womb and then after they are born. The aim is to understand how the human brain assembles itself from a functional and structural perspective. The resulting map is called a connectome and is the brain equivalent of the human genome. It will be made available to the research community to help improve understanding of neurological disorders.
First snaps made of fetal brains wiring themselves up
The first images have been captured of the fetal brain at different stages of its development. The work gives a glimpse of how the brain’s neural connections form in the womb, and could one day lead to prenatal diagnosis and treatment of conditions such as autism and schizophrenia.
We know little about how the fetal brain grows and functions – not only because it is so small, says Moriah Thomason of Wayne State University in Detroit, but also because “a fetus is doing backflips as we scan it”, making it tricky to get a usable result.
Undeterred, Thomason’s team made a series of functional magnetic resonance imaging (fMRI) scans of the brains of 25 fetuses between 24 and 38 weeks old. Each scan lasted just over 10 minutes, and the team kept only the images taken when the fetus was relatively still.
The researchers used the scans to look at two well-understood features of the developing brain: the spacing of neural connections and the time at which they developed. As expected, the two halves of the fetal brain formed denser and more numerous connections between themselves from one week to the next. The earliest connections tended appear in the middle of the brain and spread outward as the brain continued to develop.
Thomason says that the team is now scanning up to 100 fetuses at different stages of development. These scans might allow them to start to see variation between individuals. They are also applying algorithms to the scanning program that will help correct for the fetus’s movements, so fewer scans will be needed in future.
Once they understand what a normal fetal brain looks like, the researchers hope to study brains that are forming abnormal connections. Disorders such as schizophrenia or autism, for instance, are believed to start during development and might be due to faulty brain connections. Understanding the patterns that characterise these diseases might one day allow physicians to spot early warning signs and intervene sooner. Just as importantly, such images might improve our understanding of how these conditions develop in the first place, Thomason says.
Emi Takahashi of Boston Children’s Hospital says that one way to do this would be to follow a large group of children after they are born, and look back at the prenatal scans of those who later develop a brain disorder. Although she says the study is a very good first step, understanding the miswiring of the brain is so difficult that it may be some time before the results of such work become useful in clinical settings.
(Source: newscientist.com)
Foetus suffers when mother lacks vitamin C
Maternal vitamin C deficiency during pregnancy can have serious consequences for the foetal brain. And once brain damage has occurred, it cannot be reversed by vitamin C supplements after birth. This is shown through new research at the University of Copenhagen just published in the scientific journal PLOS ONE.