Ethyl alcohol administration during gestation disrupts development of sensorimotor reflexes and morphology of cerebral cortex and brachial spinal cord of albino rat newborns

The present investigation shows the effect of low dose of diluted ethyl alcohol (0.5 ml of 33% ethyl alcohol) on cerebral cortex, spinal cord and the development of sensorimotor reflexes in albino rat newborns. The newborns were divided into five groups A, B, C, D and E, each of 15 animals. Neuronal loss, oedema, pyknotic cells, vacuolation, neurocyte chromatolysis and dilated blood vessels were observed in cerebral cortex and spinal cord of the treated newborns. The intensity of nissl granules were reduced in the treated groups. The development of sensorimotor reflexes was investigated daily in the normal and treated newborns from Day 2 until reflex maturation. Grasping, surface body righting and hopping are spinal reflexes, while chin tactile placing and visual placing are cerebral reflexes. These reflexes were more retarded in their development in the treated groups than in the normal newborns. In conclusion, the present study showed that alcohol ingestion by pregnant dams at low dose lead to pathological alterations in the newborns in addition to retardation of sensorimotor reflexes in the treated groups depending on the duration of alcohol exposure. So, the most affected group was group B.

Animal research indicated a multifactorial mechanism of the teratogenicity of alcohol resulting from nutrient deficiencies, fetal hypoxia alterations in enzyme activities and cell function (Hankin et al., 2000).Ethanol may also impair lactational performance, affecting mammary gland function and newborns growth (Ludena et al., 1983).Moreover, chronic alcohol administration to the lactating rats also affects suckling-induced prolactin release (Tavares et al., 1999;Luisa et al., 2001;Paintner et al., 2012).The cerebral cortex is characterized by the presence of the pyramidal cells, and axons provide the principal output of the cortex (Hellwig, 2000).In mammalian *Corresponding author.E-mail: allam1081981@yahoo.com.Tel: +966544265061.Fax: +9664678514.
cortex, there was inside out gradient of cortical migration where the new, late-produced corticalneurons were able to move toward the surface post the layers of already migrated cells (Aboitiz,1999).In the developmental mammalian cerebral cortex, there are two early waves and other late wave of cell migration before the establishment of the cortical plate (future cerebral cortex).Motor neuron dysfunction due to spinal cord injury is a disastrous complication in humans (Sakurai et al., 2000).Impaired reflex behavior has been described in patients with spastic gait resulting from spinal cord injury (Sinkjaer et al., 1995).Also, it was believed that the primary cause of the spinal muscular atrophy is motorneuron degeneration, while muscle weakness and atrophy occur secondarily (Williams et al., 1999).The appearance and the maturation of a number of sensorimotor reflexes are components of the mature motor repertoire of the animal, and the expression of these can be correlated with the development and maturation of the nervous system (Cassidy et al., 1994).Smart and Dobbing (1971) studied the effect of early nutritional deprivation on reflex ontogeny and recorded that the development of physical features and reflexes was significantly retarded in the malnourished rats.Chronic mild protein restriction for tow generation also caused delays in the appearance of certain reflexes in nestling rats (Cowley and Griesel, 1963).
The present study aimed to investigate the effect of alcohol administration on the histological structure of both cerebral cortex and spinal cord at Day 7 and Day 14 as well as the development of sensorimotor reflexes in the rat newborns of different groups between Day 2 and Day 25.

Experimental animals
The present study was carried out on 100 albino Wistar rats (Rattus novregicus), 75 mature virgin females weighing 120 to 160 g and 25 mature males.Daily examination of vaginal smear of each virgin female was carried out to determine the estrous cycle.Mating was induced by housing proestrous females with male in ratio of 2 females with one male overnight.In the next morning, the presence of sperm in vaginal smear determined the zero day of gestation.At birth, each mother was housed with its newborns in large cage kept in a ventilated room at constant temperature on a 12:12 h light/dark cycle.Saturated rodents pellet diet manufactured by the Egyptian Company for Oil and Soap as well as some vegetables as a source of vitamins were given ad libitum.

Drug used
Ethyl alcohol was purchased from Reideld-de-Haun Company (Germany) at purity of 99.9%.Alcohol was diluted and orally administrated to pregnant females by gastric intubation daily from D7 of gestation as pure ethanol in a dose of 0.5 ml of 33% ethyl alcohol, which is equivalent to 700 mg/kg.This dose is low if compared to the doses used by Maier and West (2001), which were 2.5, 4.5 and 3.6 g/kg/day, or to the dose (6.6 g/kg/day) used by Thomas et al. (1998).

Animal grouping
The newborns of rats were divided into five groups as follows: 1. Group A: Normal newborns (control); the mothers of these newborns were given water from Day 7 of gestation till Day 25 after birth.2. Group B: The mothers of these newborns were given alcohol from Day 7 of gestation till Day 25 after birth.3. Group C: The mothers of these newborns were given alcohol from Day 7 of gestation but alcohol administration was stopped at birth and the mothers were given the chance to lactate their newborns to postnatal Day 25. 4. Group D: Newborns of treated mothers were transferred at birth to live and lactate with normal surrogate mothers to postnatal Day 25. 5. Group E: The newborns of normal mothers were transferred at birth to be lactated by treated surrogate mother for 25 days.

Postnatal investigations
The newborns were investigated by the experimenter every day and the following notes were recorded in each group.Sensorimotor reflexes (Cassidy et al., 1994) At birth, each mother was housed with its newborn in a large cage kept in a ventilated room at constant temperature on a 12:12 h light/dark cycle.Thirty newborns from Day 2 to Day 28 from each group were used for the present study.Fifty to eighty newborns from the first generation of each animal type were used in the present study from postnatal Day 2 to Day 28 (during pre-weaning period).Testing took place in an open field, which was 90 × 60 cm plastic cart with a 6 cm lip around the edge.The cart was covered with a sheet of plastic that was wiped with ethanol swabs between testing of the animals.Each test was conducted every day from postnatal Day 2 until the reflex was expressed to its adult level for 3 consecutive days.Six newborns from each animal were tested for each day of age.Each subject was tested 5 times for a given reflex at a given age and the positive responses were recorded (scores of 0/5 to 5/5).Each newborn was tested only to 3 subjects per day and was exposed to the same subject examinations after 3 days to avoid reflex learning by the newborn.For the same day and same reflex, one newborn from each litter was tested.The average score was calculated, converted to percentage and a reflex was described as being present or absent.On the first day, a reflex was observed at least once in at least one animal which was considered as the day of its appearance.A reflex was considered stable when it was expressed at the adult percentage for 3 consecutive days.The period between the appearance of a reflex and its stabilization was considered as the period of maturation.For testing, the animals were brought in a room (25°C) reserved for that purpose.All tests were conducted by the same experimenter (expert technician who ignored types of groups to achieve blind tester).The statistical package for the social sciences (SPSS for windows version 11.0; SPSS Inc, Chicago) was used for the statistical analyses.Comparative analyses of paired sample t-test were conducted by using the general linear models procedure (SPSS, Inc).Values of P > 0.05 were considered statistically insignificant.Values of P < 0.05 were considered statistically significant, values of P < 0.01 were considered statistically highly significant and values of P < 0.001 were considered statistically very highly significant.

Rooting
The animal was put on the test surface and the experimenter formed a cone with the fingers around the snout of the animal.The reflex was considered present when the animal followed the movement of the experimenter slowly withdrawing his hand.

Grasp
The animal was held in air, the sole of the hand or the foot was gently touched with the tip of a fine brush.The left and right sides were tested equally.The reflex was considered present when the animal closed stimulated hand or foot around the brush.

Hopping
The animal was held so that only one hand or foot touched the test surface; it was moved forward as the tested limb dragged on the surface.The left and right sides were tested equally.The reflex was considered present when the animal lifted its limb and hopped in the direction of the movement.The reflex tested only in the forward direction.

Body righting on the surface
The animal was held in a supine position, with the dorsum of the head and of the trunk in contact with the test surface.The reflex was considered present after the experimenter had released his hold, the animal turned on its ventrum or limbs within 15 s.

Chin tactile placing
The animal was held by posterior half of the body, and the skin of the chin was gently rubbed on the edge of the test surface.The reflex was considered present when the animal lifted one (or both) fore limb (FL) and placed it on the surface.

Visual placing
The animal was held by the tail at 10 cm from the test surface and was slowly brought closer to it.The reflex was considered present when the animal raised its head and extended its arm toward the surface before the arms came in contact with the surface.

Light microscopy
Cerebrum and brachial spinal cord were immediately cut into small pieces of 5 mm 3 and fixed in 20% neutral buffered formalin for 24 h.The tissues were washed to remove the excess of fixative and then dehydrated in ascending grades of ethyl alcohol 70, 80, 90 and 95% for 45 min each, then in two changes of absolute ethyl alcohol for 30 min each.This was followed by clearing in two changes of xylene for 30 min each.The tissues were then impregnated with paraplast plus (three changes) at 60°C for three hours and then embedded in paraplast plus.Sections (4 to 5 µm) were prepared with a microtome, de-waxed, hydrated and stained in Mayer's haemalum solution for 3 min.The sections were stained in Eosin for one min, washed in tap water and dehydrated in ethanol as described above.Haematoxylin and Eosin stained sections were prepared according to the method of Mallory (1988).

Toluidine blue stain
The prepared serial sections of cerebrum and brachial spinal cord were de-waxed then transferred to 95% alcohol; the slides were put in alcoholic colophonium solution for 5 min (10 g colophonium in 105 ml 95% alcohol).The slides were then transferred to two changes of 95% alcohol each for 3 min, followed by staining in toluidine blue 0.1% for 30 s, and then were differentiated in a mixture for 10% analene and 95% alcohol.Clearing in different changes of Cajput oil was done, and finally mounting in Canada balsam.

General developmental observations
Group A is the normal group.The newborns of group B suffered from exposure to alcohol and its toxic product as acetaldehyde intrauterine for 14 days and postnatal for 25 days.In group C, the newborns suffered from prenatal alcohol exposure.In addition, ethanol withdrawals from the mothers resulted in alteration of maternal behavior.It was observed in this study that the mothers of group C spent long time away from their newborns.Some mothers became mad and ate some of their newborns or suddenly ate the hind limb (HL) of their newborns when they were able to walk.The newborns of group D were exposed to alcohol intrauterine.Some improvement in the development was recorded in newborns of group D.
In group E, the newborns developed normally intrauterine but were transferred at birth to mothers with ingested alcohol, so these newborns will suffer from exposure to alcohol and bad lactation postnatal.The newborns varied in the time of fur appearance, ear opening and eye opening (Table 1).The mean weights of the newborns of all experimental groups were variables between Day 1 and Day 25 (Table 2).

Histoarchitecture of cerebral cortex
At Day 7, the outer molecular layer was defined (Figure 1a).The apical dendrites were perpendicular to the pial surface in both normal and treated groups (Figure 1b to f).At Day 14, the normal and treated newborns showed non obvious lamination in the cortical plate except the outer molecular layer which was sharply defined (Figure 2a and b).The normal cells of the cerebral cortex at Day 14 had spherical or pyramidal perikaryons whose nuclei were large, also the neurons were arranged in a regular pattern (Figure 2a and c).Generally the cerebral neurons appeared more developed toward the white matter (Figure 2a).
Several pathological cases were observed from the   1d).Similar results were observed at Day 14 but with less severity with presences of dilated blood vessels (Figure 3c).In group D, there were moderate neurocyte chromatolysis at Day 7 and at Day 14 but by low level (Figures 1e and 3d).Group E revealed perivascular oedema and vaculation by low level at Day 7 (Figure 1f), while at Day 14, perivascular oedema (low) and neurocyte chromatolysis (moderate) were observed (Figure 3a, c and d).
Nissl granules of the normal cells of cerebral cortex appeared as compact bodies in the form of flakes and granules.These granules were arranged around the nucleus and especially at the proximal parts of the dendrites.The intensity of the Nissl granules in the cytoplasm was variable and increased with the age progress at Day 7 and Day 14 (Figures 4a and 5a).At Day 7, the cytoplasm of the normal pyramidal neurons was well-stained (Figure 4a) than in groups B and C (Figure 4b and c).On the other hand, these neurons were moderately-stained in groups D and E (Figure 4d and e).
At Day 14, the normal pyramidal cells were well stained (Figure 5a) and moderately stained in groups D and C (Figure 5d and c), while faintly stained in groups B and E (Figure 5b and e).

Histoarchitecture of the brachial spinal cord
At Day 7, the normal motorneurons were large in size, had many processes and oval nuclei (Figure 6a and b).In group B, most motorneurons appeared small in size with the presence of some pyknotic cells (Figure 6c).In groups C, D and E, pyknotic cells were recorded (Figure 6d, e and f).At Day 14, the normal motorneurons became well differentiated and increased in size.The pyknotic neurons were obvious in groups B and C more than in groups D and E (Figure 7a, c, d, e and f).At Day 7, the normal motorneurons were well stained, so the intensity of Nissl granules was high (Figure 8a).In group B, the degenerated motorneurons appeared dark (Figure 8b).In groups C, D and E, motorneurons were moderately stained (Figure 8c, d and e).Moreover, the chromatolysis was detected in group C (Figure 8c).At Day 14, the motorneurons in normal group was deeplystained (Figure 9a).In group B, there were degenerated and pale-stained motorneurons (Figure 9b).The motorneurons of groups C and E were pale-stained (Figure 9c and e), while they were moderately-stained in group D (Figure 9d).

Sensorimotor reflexes
These parameters were examined in the newborns of all groups from Day 2 until reflex maturation.These reflexes were rooting, fore limb grasp, hind limb grasp, surface body righting, fore limb hopping, hind limb hopping, chin tactile placing and visual placing.

Rooting
This reflex was absent in 100% of the trials at all stages of     then it developed slowly.The present analysis showed significant difference between normal and treated groups as shown in Table 3.The late appearance and maturation of this reflex, especially in groups B and C, reflected the retardation in development of fore limb grasp.

Hind limb grasp:
In normal newborns, this reflex appeared later than fore limb grasp and it was detected by 20% of the trials at Day 7 and increased to reach 100% at Day 16.The linear shape of the reflex curve of normal newborns showed the regularity in the development of this reflex.In groups B and C, it appeared late at Day 13 and 14 by 5 and 16%, respectively and it took long time to reach 100% at Day 20 and 21 in groups C and B, respectively.In the latter two groups, the reflex development at the first 5 days of its expression was very slow.In groups D and E, this reflex appeared at Day 12 by 6% and increased to reach 100% at Day 20 in group D, while at Day 19 in group E. In these two groups, the shape of the reflex curves showed some fluctuations in reflex development.The level of significance between normal and treated newborns showed some variability (Table 4).

Surface body righting
This precocious reflex was already expressed by 50 and 34% of the trials in groups A and E, respectively at Day 2. In group A, it increased quickly to reach 100% at Day 5, while in group E, it increased slower than in group A and attained 100% at Day 8.In group B, this reflex appeared by 28% at Day 7 and increased slowly to attain 100% at Day 14.The irregularity in the reflex curve indicated the weakness of the newborns in this group.In groups C and D, this reflex was detected by 8 and 48% at Day 4 and Day 3 in both groups, respectively.The reflex expression increased in group D faster than in group C to reach 100% at Day 9 in group D and at Day 10 in group C. The difference between normal and treated groups was significant (Table 5).The retardation in this reflex development showed the poor coordination between fore-and hind limb Hopping Fore limb hopping: It appeared in normal newborns by 47% of the trials at Day 3 and its expression was regular and rapidly increased to attain 100% at Day 8.It was observed by 20 and 16% in groups B and C, respectively at Day 7. The reflex expression increased by very slow activity with irregular rate to reach 100% at Day 18 in group B and at Day 16 in group C. In groups D and E, this reflex appeared at Day 4 and Day 3, respectively by 30%.Then the reflex expression increased slowly to reach 100% at Day 14 in group D and at Day 13 in group E (Table 6).

Hind limb hopping:
This reflex appeared in normal group by 37% of the trials at Day 3 and its expression increased quickly with regular pattern to reach 100% at Day 10.In groups B and C, it was detected by 6 and 5%, respectively at Day 7 and increased slowly to reach 100% at Day 20 in both groups.Moreover, in groups D and E, this reflex was detected by 10.3 and 11%, respectively at Day 3 and Day 4 and its expression increased slowly to attain 100% at Day 16 in both groups.The patterns of these reflex curves of treated groups showed the abnormalities in groups B and C as compared with groups D and E. The level of significance between normal and treated groups varied (Table 7).

Chin tactile placing
The expression of this reflex was detected in normal newborns by 8% of the trials at Day 4. Reflex development was regular until it reached to 100% at Day 12 in normal newborns.Detection of this reflex in groups B and C occurred at Day 12 by 26.5 and 23%, respectively.Then it increased rapidly to reach 100% at Day 16 and 15 in group B and C, respectively.The late appearance of this reflex in these two groups indicated the retardation of these two groups.In group D, the reflex appeared at Day 9 by 20% and developed rapidly to attain 100% at Day 12, while in group E, it appeared at Day 6 by 12% and increased slowly to reach 100% at Day 14.Table 8 revealed the level of significance between normal and different treated groups.

Visual placing
This late reflex first occurred at Day 15 in normal group by 47.5% of the trials but matured rapidly to reach 100% at Day 17.It was detected in groups B, C, D and E at Day 16 by 35, 27, 66 and 20%, respectively.Its expression increased to reach 100% at Day 20 in group B, while at Day 19 in groups C, D and E (Table 9).

DISCUSSION
The groups were classified to show the most dangerous stage of alcohol exposure on the developing embryo.Group A is the normal group, groups B, C, D and E are the treated groups.Alcohol and its product acetaldehyde not only pass readily through placenta due to its solubility in water and lipids but also caused ethanol-associated placentotoxicity, which resulted in reduction of nutrition provided to the developing fetus as recorded by Luke (1990).The alcohol passes through mother's milk to her newborns (Luisa et al., 2001).In addition, alcohol leads to bad lactation because it induced inhibition of oxytocin resulting in reduction of milk ejection and consequently leads to malnutrition (Nathaniel et al., 1986).Therefore, the newborns of group B suffered from exposure to alcohol with its product, and malnutrition pre and postnatal.
In group C, the newborns suffered from prenatal alcohol exposure that led to nutrition deprivation.In addition, postnatal malnutrition regarded to sudden ethanol withdrawals for the mothers resulted in alteration of maternal behavior (Nathaniel et al., 1986).Some mothers in this group ate some of their newborns or only ate the HL of them when they were able to walk; preventing them from moving to obtain milk, and this indicates the abnormalities in the mother's behavior.The newborns of group D were exposed to alcohol with its product intrauterine, which led to malnutrition.In group E, the newborns suffered from exposure to alcohol with its product and bad postnatal lactation (malnutrition).
In the normal newborns of the present study, the fur appeared at Day 9 and delayed in the treated groups.Sampson et al. (1997) reported that alcohol causes growth retardation.Groups B and C suffered from similar worth condition, so the fur appeared at Day 12 to 13.The fur appeared at Day 11 to 12 in groups D and E, retarded than in normal group and earlier than in group B and C.This resulted from different conditions exposure of alcohol and malnutrition during development.It was obvious that the above results are in agreement with the symptoms of fetal alcohol syndrome (FAS) mentioned by Wells et al. (2012).
In the present normal newborns, ear opening was detected at Day 12 to 13. Smart et al. (1971) detected similar results in rat newborns.In treated groups, ear opening delayed but the retardation is more obvious in group B and C (at Day 15) than in group D and E (at Day 13 to 14).These results are in agreement with FAS reported by Sampson et al. (1997).The retardation in ear opening caused by alcohol led to conductive hearing loss and neurosensory hearing loss.
Eye opening occurred at Day 14 to 15 in the present group A, this result was observed also by Bolles and Woods (1964), while it was detected at Day 16 to 18 in group B, at D 16 to 17 in group C and at Day 15 to 17 in groups D and E. This retardation in treated groups is in agreement with Ledig et al. (1990Ledig et al. ( , 1991) ) who mentioned that alcohol causes developmental alterations.
The newborns of treated dams suffered from prenatal alcohol exposure, which resulted in loss of body weight.The mean body weight at birth was 4.1 ± 0.42 g which was very highly significant compared to 6.5 ± 0.07 g in the normal newborns.Nathaniel et al. (1986) and Luisa et al. (2001) recoded this reduction in weights of newborns because their mothers ingested alcohol during pregnancy.Intrauterine alcohol exposures undermine the primary function of the placenta, so it leads to growth deficiency to the developing fetus, which is a symptom of FAS (Sampson et al., 1997).The intrauterine malnutrition  to the developing fetuses caused by alcohol prevents normal growth (Luke, 1999).The most dangerous effect of alcohol on embryos is intrauterine because fetuses lack the enzymes required to break down the substances once they have entered the blood supply (Adlard and Dobbing, 1971).The change in weights was regularly increased with age in normal group while in the treated groups the change in weights was slow except in newborns of group D that fostered from normal mothers.In groups B and E, the alcohol affects on the function of  mammary gland thus, it leads to impaired lactation (Ludena et al., 1983;Luisa et al., 2001).So, there were nutritional deprivations.The treated newborns took longer time to attach to the nipple and they were incapable of exerting adequate pressure, also they had a reduced number of rapid rhythmic sucks per minute of suckling (Chen et al., 1982).Luisa et al. (2001) found that maternal alcohol consumption resulted in reduction of organs weights of rat newborns.The mechanism of the teratogenicity of alcohol resulted from nutrient deficiencies, fetal hypoxia alterations in enzyme activities and cell function (Zajac and Abel, 1992).Also, Ledig et al. (1991) mentioned that paternal alcohol exposure leads to reduction in body weight of the offspring.The present study showed that the typical normal pyramidal neurons appeared with their apical dendrites project toward the pial surface.In treated groups, the density of cerebral cortex cells was low because the alcohol interferes with the neuronal differentiation, interrupts cells migration and increases the rate of cells death.These results are in agreement with Daniel et al. (1996), Maier and West (2003) and O' Leary et al. (2012) who mentioned that ethanol induced neuronal loss and consequently abnormal behaviors due to neuronal deficits.Goodlett et al. (1992) reported that spatial memory deficits have been correlated with loss of pyramidal cells in the cerebral cortex.In addition, Resnickoff et al. (1993) reported that alcohol interfered with the activity of growth factors, which regulate cell proliferation and survival.Loss of normal growth factor signaling prevents normal growth and development.Moreover, Miller (1996) recorded that alcohol can alter the speed of cell division.
The most striking features of brain damage in treated groups was revealed by oedema, pyknotic cells, vaculation, neurocyte chromatolysis and dilated blood vessel which were detected at all investigation stages.The severity of neurocyte chromatolysis and vaculation decreased with age progress.The above pathological cases reflect the brain injures caused by ethanol (Iqbal et al., 2004).Moreover, Daniel et al. (1996) recorded that alcohol caused brain damage.These changes were because newborns were exposed to malnutrition which resulted from bad behavior of mother postnataly due to alcohol deprivation (Nathaniel et al., 1986).The severity of brain damage decreased with age progression because the newborns may develop an antagonistic mechanism to the alcohol effect.At Day 14, no pathological cases were detected in cerebral cortex, which indicates the improvement of the newborns in group D when stopped to ingest alcohol and lived in normal condition.The present neurocyte chromatolysis was detected by high level due to chronic alcohol exposure, which leads to cells loss as observed by Sandra and Michael (2003).
In the present treated groups, there were motorneurons appearing as pyknotic at Day 7.They were detected in group B but by a low rate in group C and D because of ethanol withdrawal and improvement in the developmental condition.The improvements in group D is better than group C.These results are in accordance with West et al. (2001), Maier and West (2003) and Sandra and Michael (2003) who reported that alcohol ingestion by pregnant dams caused cells loss especially in the central nervous system (CNS) of embryos during the development.Also, exposure to ethanol reduced motorneurons excitability and decreased motorneurons ability to generate repetitive action potential firing, without significantly changing motorneurons resting membrane potential (Cheng et al., 1999).Also, it had effects on the pattern of neuronal firing, which vary considerably in different areas of the CNS.Therefore, in comparing with the existing literature, ethanol induced dysfunction of neuronal electrical activity in the mammalian spinal cord (Crews et al., 1996).
The intensity of nissl granules in the neurons referred to the high metabolic activity of these neurons (Stevens and Lowe, 1997).In normal newborns, the intensity of nissl granules in the pyramidal cells was high at all investigation stages if compared with other treated groups.Alcohol impair cell metabolism (Hu et al., 1995) and leads to protein deficiency (Luke, 1990) so the intensity of nissl granules is low in the treated groups.These evidences are in agreement with Stevens and Lowe (1997) who found the human newborns with high metabolic activity.Heaton et al. (2000) mentioned that alcohol causes disturbance in the metabolism and leads to cell dysfunction.This explains the reduction in the activity of the treated newborns supported by the results of sensorimotor reflexes.
The present experimental groups were different in the developmental degree of sensorimotor reflexes at the same age.Each reflex reflects the state of a certain part in the CNS and the rate of its development (Cassidy et al., 1992;Cabana et al., 1993).The retardation resulted from alcohol exposure, which leads to prenatal (Luke, 1990) and postnatal malnutrition (Nathaniel et al., 1986).Smart and Dobbing (1971) recorded that malnutrition caused retardation in the development of sensorimotor reflexes.In addition, alcohol induced cell loss in the present CNS as reported by Resnickoff et al. (1993), Thomas et al. (1998), Heaton et al. (2000), West et al. (2001) and Ohrtman et al. (2006).Cassidy et al. (1992) recorded that sensorimotor reflexes expression were mediated by CNS neurons.Therefore, the losing of these neurons will affect the expression of these reflexes.Daniel et al. (1996) reported that the behavioral abnormalities in the developing newborns were related to CNS regions where neuronal loss occurs.It was recorded that maternal alcohol consumption leads to relaxation of the infant and thus promote the infant sleep (Mulder et al., 1998) as well as delays the motor development (Little, 1990;Thanabhorn et al., 2006).In addition, it causes attention deficit and hyperactivity disorder in the children (Coles et al., 1997).
In addition, alcohols impair synapse function and neuronal connection (Costa et al., 2000).Moreover it had effect on the metabolism process where it reduced cellular and neuronal glucose uptakes as well as the level of glucose transporter protein (Hu et al., 1995).Also, the present study showed a good relation between intensity of Nissl granules and newborns activation where its intensity in the neurons refers to the high metabolic activity of these neurons (Stevens and Lowe, 1997).Therefore, the low activation of the newborns of the treated groups was reflected by the intensity of Nissl granules.The newborns activation in the reflex expression was indicated by the amount of Nissl granules in the motor neurons of both groups.The late appearance and maturation of the hind-limb grasp reflex resulted from dysfunctions of spinal cord neurons in the treated newborns and this is in agreement with Miller (1996).These results are in accordance with alcohol that delays the motor development (Little, 1990).

Conclusion
The present study showed that alcohol ingestion by pregnant dams at low dose leads to pathological alterations in the newborns in addition to the retardation in the development of sensorimotor reflexes, external features and body weights in the treated groups depending on the duration of alcohol exposure.
a.The weights of 10 newborns from each group daily recorded.b.The time of fur appearing.c.The time of ear opening d.The time of eye opening.

Figure 4 .
Figure 4. Sagittal sections in the cerebral cortex at Day 7 showing the distribution of Nissl granules and degenerated cells (DC).Group A (a), group B (b), group C (c), group D (d), group E (e).The arrow refers to the apical dendrites (Toluidine-blue stain, ×1000).

Table 1 .
Changes of weights in newborns of each group from Day 1 to Day 25.

Table 2 .
Appearance of some external features.
(Figures 1c, 2b and 3b).In group C, at Day 7, vaculation was recorded by high level, perivascular oedema and pyknotic cells were detected by moderate level, while neurocyte chromatolysis were observed by low level (Figure

Table 3 .
The ontogenesis of FL grasp reflex.

Table 4 .
The ontogenesis of HL grasp reflex.

Table 5 .
The ontogenesis of body righting on a surface reflex.

Table 6 .
The ontogenesis of FL hopping reflex.

Table 8 .
The ontogenesis of chin tactile placing reflex.

Table 9 .
The ontogenesis of visual placing reflex.