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Medical and Health Science Journal, MHSJ
ISSN: 1804-5014 (Online) 1804-1884 (Print)
Volume 15, Issue 3, 2014, pp.65-68
DOI: http://dx.doi.org/10.15208/mhsj.2014.10
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THE BRAIN DAMAGE IN FETAL ALCOHOL SYNDROME
(EXPERIMENTAL AND PATHOLOGICAL STUDY)
The research compares clinical and experimental studies of the
effects of antenatal alcohol exposure on the central nervous system
development. The experimental model, involving Vistar rats, was
used to analyze the effects of one-month alcohol intake before and
during pregnancy. To conduct light-optical analysis we used brain of
one-month-old rat offsprings.
Pathological studies of brain in infants with fetal alcohol syndrome
(three lethal cases) revealed focuses of tissue rarefaction and
dystrophic degeneration in the neurons along with a decreased
amount of basket cells in the cerebellum. Such findings are in
agreement with morphological analyses of brain, conducted on
experimental animals.
Moreover, employing heterogeneous solid-phase immunoassays, in
experimental animals during pregnancy we analyzed the level of the
transforming growth factor ß1 (ТGF- ß1).
Keywords:
ZHANNA MALAKHOVA,
ALEXEY EFREMOV
Department of Pediatrics,
Ural State Medical University, Russia
Alcohol, fetal alcohol syndrome, growth factor
Source: Zhanna Malakhova, Alexey Efremov, 2014. “The brain damage in fetal alcohol syndrome (experimental and
pathological study)”, Medical and Health Science Journal, Vo.15(3), pp.65-68, DOI: http://dx.doi.org/10.15208/mhsj.2014.10
Introduction
Complicated course of pregnancy and delivery strongly affect infant CNS and mental
development in comparison with endogenous and exogenous factors during the postnatal
period. Among factors, which negatively affect normal course of pregnancy and cause a
variety of deviations in fetus and infant development, along with somatic and infectious
diseases of a pregnant woman, a significant adverse effect is caused by toxic exposure, in
particular by alcohol consumption during pregnancy.
Fetal alcohol syndrome (FAS) is a pattern of mental and physical defects, which result
from alcohol consumption during pregnancy (CDC, 2002). Currently, this diagnosis is
based on three facial characteristics (smooth philtrum, thin upper lip and small eye
openings), growth deficiency, underweight, structural and functional changes of the
central nervous system and alcohol consumption during pregnancy (Astley and Clarren,
1995).
The majority of children with FAS syndrome are characterized by physical and mental
retardation; they have sensory processing disorder and behave in a hyperactive manner.
According to many reviews, FAS is one of the most significant reasons of mental
retardation (Mirkes, 2003).
The aim of the research was to evaluate the impact of fetal alcohol exposure on
cytomorphological features of the central nervous system in experimental animals and
compare the obtained data with pathological studies of autopsied brain, obtained from
newborn children who died due to FAS (three lethal cases).
Materials and methods
The research was conducted during fall-winter season. Thesubjectswere 26 Vistar rats1-2
months old that weighed 280-300 g. Rats were kept at room temperature, food was
provided ad libitum at all times. They were divided into two groups; group 1 was the main
group including 13 animals, which had access to 15% ethanol solution instead of water
during one month before and during pregnancy, and group 2 was the control group,
comprised of 13 intact rats. To conduct light optical analysis, we used brain from
© 2014 Prague Development Center
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Medical and Health Science Journal / MHSJ / ISSN: 1804-5014 (Online) 1804-1884 (Print)
offspring rats at the age of one month old (11 animals from each group). Brain tissues
were treated with 5% formalin in the volume ratio 1:10. Upon fixation, segments of brain
tissue were cut out of convexital surface of the sensorimotor cortex, hypothalamus, and
cerebellum and embedded in paraffin. Staining was carried on using hematoxylin eosin,
according to van Gieson's and Nissl's methods.
In parallel we analyzed the level of the transforming growth factor ß1 (ТGF- ß1) during
pregnancy (9-12 days of pregnancy) in rats. ТGF- ß1 plays an important role in growth
regulation, tissue differentiation, apoptosis, modulating of the immune system,
morphological development of an infant (Oyvin, 1960). We used heterogeneous solidphase immunoassays (test system Bender MedSystems, Austria) and the photometer
STATFAX. In the statistical analysis, we used Student’s t-test (CDC, 2002).
Results and discussion
Defects in eyes, ears, skull development were visualized by eye. In the group 1 distinct
changes were observed, such as cortical focuses of tissue rarefaction of different intensity
and extension (Figure 1). Although most focuses of tissue rarefaction were located in the
medial cortex, occasional focuses of tissue rare faction were observed in all the cortical
layers. We also observed dystrophic changes in the neurons, including mainly
chromatolysis in medial cortex and pycnotic changes in the upper layers.
FIGURE 1. MORPHOLOGICAL CHARACTERISTICS OF THE CEREBRAL
HEMISPHERES SURFACE (rays indicate on tissue rarefaction)
FIGURE 2. MORPHOLOGICAL CHARACTERISTICS OF NUCLEI IN THE HYPOTHALAMUS
(rays indicate on complete absence of neurocrine granules)
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Medical and Health Science Journal / MHSJ / ISSN: 1804-5014 (Online) 1804-1884 (Print)
FIGURE 3. MORPHOLOGICAL CHARACTERISTICS OF THE CEREBELLUM (rays indicate on
tissue rarefaction and a drastic reduction in the number of basket cells)
a. control group
b. main group
FIGURE 4. MORPHOLOGICAL CHARACTERISTICS
OF THE CEREBRAL CORTEX
FIGURE 5. MORPHOLOGICAL
CHARACTERISTICS OF THE CEREBELLUM
In nuclei in the hypothalamus (Figure 2), we also observed focuses of tissue rarefaction
and cell dystrophic changes. Chromatolysis and pycnotic changes, as well as a decrease
(and sometimes a complete absence) of neuroendocrine granules, were dominated.
In the cerebellum (Figure 3) we observed thinning in gyri. In the granular layer of the
cerebellar cortex we showed bands of tissue rarefaction and a drastic reduction in the
number of basket cells. The remained cells were unevenly located at different layers.
Chromatolysis and pycnotic changes dominated.
Histological analysis of brain tissues in the control group of animals did not show any
substantial changes. In the cerebral cortex we could observe clear stratification of
neurons, there was also mild perivascular edema in the form of the enlargement of
Vickhow-Robin space, most likely due to acute hypoxia caused by euthanasia of animals.
In nuclei in the hypothalamus neurons were located unequally, in the cytoplasm we could
see light secretion granules, which was a sign of the neurocrine function. The granular
layer of the cerebellum was distinctively seen, the basket neurons (Purkinje cells) were
located at the border of the granular layer and the white matter. The cytoplasm was
roundly shaped; nucleus and nucleolus, as well as cytoplasmic borders were distinctively
seen.
The obtained data we compared with three clinical pathological cases of infant lethal
outcomes, caused by FAS. Autopsy showed acute venous congestion in the brain and all
© 2014 Prague Development Center
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Medical and Health Science Journal / MHSJ / ISSN: 1804-5014 (Online) 1804-1884 (Print)
internal organs. In samples of brain tissues (cerebral hemispheres surface, hypothalamus,
the cerebellum)we revealed focal lesions and dystrophic changes in neurons, along with a
decreased amount of basket cells in the cerebellum(Figures 4-5).
InthecomparativeanalysisofpathologicalfindingsandlevelsofТGF-β1,
werevealedanincreaseintheТGF-β1 concentration in the study group M = 187.9 ng/ml (in
the control group M = 129.7 ng/ml), t = 2.68, р< 0.02. It is known, that ТGF-β1 is one
of the key players in the cell growth regulation, cell differentiation and apoptosis, such
processes right after cell fertilization.
Many authors report that the accumulation of this transforming factor in blood (Ogura,
Takakura, Yoshida, Nishiikawa, 1998) may be connected with the blocking of ТGF-β1
receptors of growing cells by alcohol, which results in the deterioration of cell growth and
apoptosis.
It is also known that alcohol induces an early transformation of radial astroglia into
astrocytes, which leads to an impaired migration of neurons within the brain (Miller and
Robertson, 1993).
Conclusion
Based on our experimental findings we report a severe impact of alcohol on the brain cells
of alcohol-fed rat offsprings. In particular, we observed focuses of tissue rarefaction and
dystrophic changes in neurons in the form of chromatolysis and pycnotic changes in
cortex, hypothalamus, and the cerebellum. Besides, we showed a decrease (and sometimes
a complete absence) of neuroendocrine granules. These findings are in agreement with
morphological parameters of cerebral cortex of died infants with FAS.
Observed elevated levels of ТGF-β1 in pregnant alcohol-fed female rats points out on the
receptors deficiency in both female rats and their offspring.
Therefore, the reveled data on the expression of the growth factor ТGF-β1 are in
agreement with morphological changes in the brain of experimental animals and can be
extrapolated on the similar processes in the mammalian and human brain development
when exposure to alcohol.
Acknowledgements
Bazarnyy Vladimir Victorovich, professor of the Department of Clinical Laboratory
Diagnostics and Bacteriology, Ural State Medical University, Yekaterinburg,Russia.
Kleyn Alexei Veniaminovich, Central Research Laboratory of Ural State Medical
University, Yekaterinburg,Russia
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