Fetal Alcohol Syndrome

Fetal Alcohol Syndrome

Many studies have established that a developing organism is susceptible to exogenous and endogenous factors during certain stage of the organism’s development. The effects of ethyl alcohol or ethanol on the developing fetus, which manifest a variety of characteristic abnormalities, are collectively called Fetal alcohol Syndrome. Ethanol exposure to the fetus causes various malformation ranging from the cellular to the organismic levels with the eventual results frequently being different levels of mental retardation (3).

Chick embryo studies provide a relatively good model for defining the effects of ethanol at many organizational levels of neurogenesis, cell death, neuronal migration and differentiation, cell to cell connectivity, and synaptic function When ethanol is administered to embryos on days one to three of development, the cholinergic neuronal phenotypes were markedly decreased possibly in the sparing of catecholaminergic phenotypes which were increased. This differential sensitivity of these two early neuroblast populations to ethanol may also reflect the difference in their ontogenesis: cholinergic elements are reported to be expressed as early as the primitive streak, whereas catecholaminergic elements appear later (3).

Embryos on embryonic day one are most susceptible to the effects of ethanol. Embryonic day one in the chick is marked by an active process of neurogenesis and neuro-organization. The neural tube elements are made during this early embryonic period. Brodie and Vernadakis inspected the effect of ethanol on cholinergic spinal cord neurons during this embryonic period. The neuroblast during this period shows plasticity with respect to neurotransmitter phenotypes, when ex...

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...s in these target organs at critical developmental periods would result in defects of these organs (5).

BIBLIOGRAPHY:

Abel, E. and Sokol, R. A Revised Conservative Estimate of the Incidence of FAS and Its Economic Impact. Alcoholism, 0145-6008:514-524 (1991).

Bonthius, D. and West, J. Permanent Neuronal Deficits in Rats Exposed to Alcohol During the Brain Growth Spurt. Teratology, 44:147-163 (1991).

Brodie, C. and Vernadakis, R. Critical Periods to Ethanol Exposure During Early Neuroembryogenesis in the Chick Embryo: Cholinergic Neurons. Developmental Brain Research, 56:223-228 (1990).

Burd, L. and Martsolf, J. Fetal Alcohol Syndrome: Diagnosis and Syndromal Variability. Physiology and Behavior, 46:39-43 (1989).

Keir, W. Inhibition of Retinoic Acid Synthesis and its Implications in Fetal Alcohol Syndrome. Alcoholism. 15/3:560-564 (1991).