Fetal nervous system

Samat HB, Nochhn D, Bom DE (1998) Nenronal nuclear antigen (NenN) A marker of nenronal matnration in early human fetal nervous system. Brain Dev 20 88-94. 

Absorbed metallic mercury crosses the placenta, and the fetal blood may concentrate mercury to levels 10 or more times the levels found in the maternal blood. Therefore, the developing fetal nervous system may be quite sensitive to maternal exposures to mercury vapors. 

In 1999, researchers reported a study of fetal outcome following maternal occupational exposure to common organic solvents in occupations, such as factory workers, laboratory technicians, artists, office workers, and so forth. The data showed that occupational exposure to common organic solvents during pregnancy is associated with a 10-fold increased risk of major fetal malformations.27 This is occupational exposure, not some dramatic accidental acute poisoning. By implication, subtle effects on the fetal nervous system, effects that shape emotional and intellectual behavior, are to be expected after maternal exposure to ambient concentrations of organic solvents ordinarily used in many workplaces. 

Adequate amounts of folic acid are especially important in fetal development, during the first eight weeks of life following fertilization. The compound is essential to promote normal development of the fetal nervous system. Folic acid deficiencies in the mother during this period may result in neural tube defects such as spina bifida or anencephaly, a condition in which the fetus brain and skull fail to develop normally. The U.S. Centers for Disease Control and Prevention recommend that pregnant women take 600 micrograms of folic acid daily to avoid such problems. 

Adequate maternal thyroxine concentration is essential for fetal nervous system maturation. 

The neurological signs and neurq>athological evaluation, particularly in cerdDral cortex may be temporally related to alteration of fetal nervous system development as early as the first trimester (9, 11, 12, 14, 15, 16). 

Schonemann MD, Muench MO, Tee MK, Miller WL, Mellon SH (2012) Expression of P450cl7 in the human fetal nervous system. Endocrinology 153 2494-2505... 

Phenytoin Central nervous system malformations, fetal growth restriction... 

Warfarin Growth restriction, fetal hemorrhage, skeletal and central nervous system malformations... 

Bondurand, N., Natarajan, D., Thapar, N., Atkins, C. and Pachnis, V. Neuron and glia generating progenitors of the mammalian enteric nervous system isolated from fetal and postnatal gut cultures. Development 130 6387-6400, 2003. 

Grossly elevated concentrations of dissolved copper produce teratogenicity in fish embryos. A significant number of malformed fish larvae came from eggs treated with 500 pg Cu/L (Birge and Black 1979). In studies with laboratory animals and elevated concentrations of copper salts, copper penetrates the placental barrier into the fetus intramuscular injection of 4 mg Cu/kg BW early in pregnancy adversely affects fetal central nervous system development (Aaseth and Norseth 1986). In humans, no definitive data are available on whether copper can cause birth defects however, incubation of human spermatozoa with metallic copper results in loss of sperm motility (Aaseth and Norseth 1986). 

Copper deficiency in humans and other mammals is characterized by slow growth, hair loss, anemia, weight loss, emaciation, edema, altered ratios of dietary copper to molybdenum and other metals, impaired immune response, decreased cytochrome oxidase activity, central nervous system histopathology, decreased phospholipid synthesis, fetal absorption, and eventually death (NAS 1977 Gallagher 1979 Kirchgessner et al. 1979 USEPA 1980 ATSDR 1990 Percival 1995). 

Absorption readily absorbed by intestine, food will delay absorption Sensitive individuals fetus (fetal alcohol syndrome - FAS) Toxicity/symptoms developing nervous system very sensitive to low levels of exposure children - lowered IQ, learning and behavioral problems adults — memory loss, inebriation, liver disease, cancer... 

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