Cadmium significantly changes major morphometrical points and cardiovascular functional parameters during early development of zebrafish.

Living organisms are commonly exposed to cadmium and other toxic metals. A vast body of research has shown the significant effects of these toxic metals on developmental processes. In order to study the role of toxic metals on early developmental stages of eukaryotes, we explored the effect of cadmium (Cd2+) contaminant on zebrafish. Thus, zebrafish embryos were exposed to 3 mg/L (16.7 µM) Cd2+ for 96 h and imaged every 24 h from the exposure onwards. Hatching rates of the eggs were determined at 72 h, followed by analyses at 96 h for: survival rate, morphometrical factors, and functional parameters of the cardiovascular system. Interestingly enough, significant hatching delays along with smaller cephalic region and some morphological abnormalities were observed in the treatment group. Moreover, substantial changes were noticed in the length of notochord and embryo, absorption of yolk sac with shorter extension, area of swimming bladder, as well as pericardium sac after Cd2+ treatment. Cadmium also caused significant abnormalities in heart physiology which could be the leading cause of mentioned morphological deformities. Herein, our results shine light on systematic acute embryological effects of cadmium in the early development of zebrafish for the first time.

Teratogenicity of valproic acid and its constitutional isomer, amide derivative valnoctamide in mice.

OBJECTIVES: The anticonvulsant valproic acid (VPA) has a known teratogenic effect capable of inducing major congenital malformations and developmental disorders. A comparative teratogenicity study of VPA and its analog valnoctamide (VCD), which is a new generation candidate antiepileptic drug, was carried out using Swiss Vancouver (SWV) mice. METHODS: Pregnant SWV dams were treated with either a single intraperitoneal injection of VPA (1.8 and 2.7 mmol/kg), VCD (1.8 and 2.7 mmol/kg), or vehicle on E8:12 (gestational day:hour). The numbers of implantation and resorption, viable and dead fetuses, and the presence of gross fetal visceral and skeletal abnormalities were determined (E18). Real-time Polymerase chain reaction (RT-PCR) arrays were used to analyze the expression of 84 genes related to the processes of neurogenesis and neural stem cell differentiation. RESULTS: Significant decreases in pregnancy weight gain and the number of live fetuses were observed when VPA was administered at the high dose, whereas the percentage of exencephalic fetuses was significantly increased in VPA treated compared with an equivalent VCD dosage group. There was a dose-related increase in visceral defects in the VPA-exposed fetuses. Missing skull bones and fused vertebrae in fetuses occurred at the high dose of VPA. Three genes (Mtap2, Bmp8b, and Stat3) were significantly upregulated and one (Heyl) was downregulated in samples from VPA-treated dams. CONCLUSIONS: The study demonstrates that the teratogenicity of VPA was significantly greater than that of an equimolar dose of VCD. Four genes (Mtap2, Bmp8b, Stat3, and Heyl) represent candidate target genes for the underlying teratogenic mechanism responsible for VPA-induced malformations.

Middle-aged individuals with thalidomide embryopathy have undergone few surgical limb procedures and demonstrate a high degree of physical independence.

BACKGROUND: Thalidomide is known to have induced thalidomide embryopathy (TE) in more than 10,000 live-born children worldwide between 1957-1962. AIM: The aim of this study was to investigate the need for orthopaedic surgery and limb orthosis in relation to function and physical independence in middle-aged individuals with TE. METHODS: 13 women/18 men with a mean age of 45.8 (SD 1.1) years were included. Information about limb surgery, the use of orthotic devices, jobs, accommodation, disability adjustments and personal assistants was collected. Physical function was measured by a modified general function score. The time needed for activities of daily living (ADL) was collected. Individuals with proximal focal femoral deficiency, PFFD, and participants in need of home or work adaptations were compared with the rest of the group. RESULT: 31 surgical procedures had been performed in the extremities. Three individuals were in need of personal assistance and seven had disability-adjusted homes. 28 individuals were working and 24 reported participation in exercises. Those with PFFD had significantly lower function score and needed a significantly longer time for ADL in the morning (p = 0.001 and p = 0.032). The group in need of home or work adjustments had significantly lower function score and needed longer time for morning ADL (p = 0.012 and p = 0.009). DISCUSSION: Few orthopaedic procedures had been performed. The TE individuals except the ones with PFFD and those in the need of disability adjustments, were mostly active workers, reported good physical function and participated in exercises, despite limb malformations.

Evaluation of embryotoxic and teratogenic effects of the oil extracted from Caryocar brasiliense Cambess pulp in rats.

The objective of this study was to evaluate the maternal, embryotoxic and teratogenic effects of Caryocar brasiliense pulp oil (OPCB), oil widely used in Brazilian cuisine and traditional medicine. Pregnant Wistar female rats were used in this study for three treatment groups (250, 500 and 1000 mg/kg/day) and a control group. The OPCB was administered orally throughout the period of organogenesis of females (6th until the 15th day of gestation). The pregnant females were gross necropsied on d20, followed by maternal and fetus examination, to evaluate the teratogenicity, reproductive and developmental performance of OPCB. The results showed there was no significant statistical difference in the ponderal evolution of the pregnant females, as well as in the behavioral, hematological, biochemical or histopathological data, indicating the absence of maternal toxicity of the oil. The mean number of corpora lutea, implantation and resorption sites, as well as all calculated reproductive rates, also remained statistically similar between the groups, indicating low embryotoxic effects of the tested plant specie. In fetal examination, external anomalies and skeletal abnormalities were observed in all treated and control groups. The NOAEL for maternal toxicity and embryo/fetal development for the OPCB administered by gavage, was 1000 mg/kg/bw/day.

Complex Anatomic Abnormalities of the Lower Leg Muscles and Tendons Associated With Phocomelia: A Case Report.

Musculoskeletal anatomy is widely known to have components that stray from the norm in the form of variant muscle and tendon presence, absence, origin, insertion, and bifurcation. Although these variant muscles and tendons might be deemed incidental and insignificant findings by most, they can be important contributors to pathologic physiology or, more importantly, an option for effective treatment. In the present case report, we describe a patient with phocomelia and Müllerian abnormalities secondary to in utero thalidomide exposure. The patient had experienced recurrent bilateral foot pain accompanied by numbness, stiffness, swelling, and longstanding pes planus. These symptoms persisted despite conservative treatment with orthotics, steroids, and nonsteroidal anti-inflammatory drugs. Radiographic imaging showed dysmorphic and degenerative changes of the ankle and foot joints. Further investigation with magnetic resonance imaging revealed complex anatomic abnormalities, including the absence of the posterior tibialis and peroneus brevis, lateralization of the peroneus longus, and the presence of a variant anterior compartment muscle. The variant structure was likely a previously described anterior compartment variant, anterior fibulocalcaneus, and might have been a source of the recurrent pain. Also, the absence of the posterior tibialis might have caused the pes planus in the present patient, considering that posterior tibialis tendon dysfunction is the most common cause of acquired pes planus. Although thalidomide infrequently affects the lower extremities, its effects on growth and development were likely the cause of this rare array of anatomic abnormalities and resulting ankle and foot pathologic features.

Cognitive and Affective Symptoms Experienced by Cancer Patients Receiving High-Dose Intravenous Interleukin 2 Therapy: An Integrative Literature Review.

BACKGROUND: Alterations in cognitive/affective functioning are among the most challenging adverse effects experienced by 80% of patients with metastatic melanoma and metastatic renal cell carcinoma undergoing high-dose interleukin 2 (IL-2) therapy. OBJECTIVE: The purpose of this literature review is to describe what is known about IL-2-induced cognitive/affective symptoms, their prevalence, and level of severity and synthesize findings to determine areas for future research to address symptom management challenges. This review describes the IL-2 patient experience and the pathophysiology leading to these changes. METHODS: An online electronic search using PubMed was performed to identify relevant literature published between 1992 and 2015. Of the original 113 articles, information was extracted from 9 articles regarding cognitive symptoms, affective symptoms, sample size, research design, reliability, and validity. RESULTS: Our review suggests that the trajectories, breadth, and depth of cognitive/affective symptoms have yet to be described. Despite intervention studies designed to address the psychosocial complications of IL-2, an understanding of the level of altered cognitive/affective symptoms experienced by IL-2 patients remains unclear. CONCLUSION: Our literature review reveals a lack of standardization when assessing, reporting, and managing cognitive/affective symptoms. Patients/family members have reported cognitive/affective symptoms to be the most alarming and difficult symptoms, yet these symptoms are not adequately screened for, and patients were not informed about potential changes. IMPLICATIONS FOR PRACTICE: Assessing patients for cognitive/affective alterations is important to reduce anxiety while improving outcomes. Education about the illness trajectory (what to expect during/after treatment) can help care partners/patients set realistic shared expectations and increase coping.

A newborn with teratogenic effect of imatinib mesylate: a very rare case report.

OBJECTIVE: To report a case of teratogenic effect of imatinib mesylate (IM) in a newborn, whose mother was suffering from chronic myelogenous leukemia and was treated with IM for 4 years, including during her pregnancy. CASE PRESENTATION AND INTERVENTION: The newborn was diagnosed with microtia of the right ear, preauricular tag on the left side, absence of right depressor angular oris muscle, and imperforate anus. Infantogram showed dextrocardia, hemivertebrae in the thoracic region and cervical spina bifida occulta. The newborn was operated on for the imperforate anus and was discharged in good condition. CONCLUSION: This case revealed that IM is not safe for the fetus and leads to teratogenicity. Hence, we recommend that pregnant women should not be treated with IM.

Long-term toxicity of reduced graphene oxide nanosheets: Effects on female mouse reproductive ability and offspring development.

Reduced graphene oxide (rGO) nanosheets have emerged as novel materials for cancer therapeutics. Their toxicity has attracted much attention since these nanomaterials may have great potential for clinical cancer treatment. Here we report the influence of rGO exposure on female mouse reproductive ability and offspring development. Mouse dams were injected with small or large rGO nanosheets at different doses and time points, pre- or post-fertilization. The sex hormone levels of adult female mice did not significantly change compared with the control group after intravenous injection with either small or large rGO, even at a high dose (25 mg/kg). Mouse dams could produce healthy offspring after treatment with rGO nanosheets before pregnancy and at an early gestational stage (∼6 days). Despite the successful delivery of offspring, malformed fetuses were found among rGO-injected dam litters. All mice had abortions when injected with low (6.25 mg/kg) or intermediate (12.5 mg/kg) doses at a late gestational stage (∼20 days); the majority of pregnant mice died when injected with the high dose of rGO at this stage of pregnancy. Interestingly, all surviving rGO-injected mouse mothers gave birth to another litter of healthy pups. The results presented in this work are important for a deeper understanding of the toxicity of rGO nanosheets on female reproductivity and their offspring development.

Prenatal diethylstilbestrol induces malformation of the external genitalia of male and female mice and persistent second-generation developmental abnormalities of the external genitalia in two mouse strains.

Potential trans-generational influence of diethylstilbestrol (DES) exposure emerged with reports of effects in grandchildren of DES-treated pregnant women and of reproductive tract tumors in offspring of mice exposed in utero to DES. Accordingly, we examined the trans-generational influence of DES on development of external genitalia (ExG) and compared effects of in utero DES exposure in CD-1 and C57BL/6 mice injected with oil or DES every other day from gestational days 12 to 18. Mice were examined at birth, and on 5-120 days postnatal to evaluate ExG malformations. Of 23 adult (>60 days) prenatally DES-exposed males, features indicative of urethral meatal hypospadias (see text for definitions) ranged from 18% to 100% in prenatally DES-exposed CD-1 males and 31% to 100% in prenatally DES-exposed C57BL/6 males. Thus, the strains differed only slightly in the incidence of male urethral hypospadias. Ninety-one percent of DES-exposed CD-1 females and 100% of DES-exposed C57BL/6 females had urethral-vaginal fistula. All DES-exposed CD-1 and C57BL/6 females lacked an os clitoris. None of the prenatally oil-treated CD-1 and C57BL/6 male and female mice had ExG malformations. For the second-generation study, 10 adult CD-1 males and females, from oil- and DES-exposed groups, respectively, were paired with untreated CD-1 mice for 30 days, and their offspring evaluated for ExG malformations. None of the F1 DES-treated females were fertile. Nine of 10 prenatally DES-exposed CD-1 males sired offspring with untreated females, producing 55 male and 42 female pups. Of the F2 DES-lineage adult males, 20% had exposed urethral flaps, a criterion of urethral meatal hypospadias. Five of 42 (11.9%) F2 DES lineage females had urethral-vaginal fistula. In contrast, all F2 oil-lineage males and all oil-lineage females were normal. Thus, prenatal DES exposure induces malformations of ExG in both sexes and strains of mice, and certain malformations are transmitted to the second-generation.

Prenatal exposure to selective serotonin reuptake inhibitors and infant outcome.

BACKGROUND: The selective serotonin reuptake inhibitors are prescribed increasingly also during pregnancy. Although a number of studies have assessed their safety, data concerning congenital malformations and adverse perinatal outcome are conflicting. METHODS: Literature search in PubMed until March 31, 2012, including original research articles, meta-analyses, and reviews. RESULTS: Fluoxetine and paroxetine use in early pregnancy has been associated with a small increased risk for specific cardiovascular malformations in some studies, fluoxetine with ventricular septal defects and paroxetine with right ventricular outflow tract defects. The observed absolute risk for these specific malformations is small. Data on preterm birth, low birth weight, and being small for gestational age have been conflicting; and mother's underlying depression is obviously an important confounder. Respiratory distress and neonatal adaptation problems are common in prenatally exposed infants, and an increased risk for persistent pulmonary hypertension of the newborn has been observed in several studies. Although several studies have not confirmed an increased risk for adverse neurodevelopment, a recent study observed an increased risk for autism spectrum disorders in prenatally exposed offspring. CONCLUSIONS: Causality cannot be confirmed in observational study settings. However, parallel results in individual studies regarding the cardiac malformations and pulmonary hypertension of the newborn, together with an existing biologically plausible mechanism behind these events may support causality. Considering the important role of serotonin in central nervous system development, more studies are needed to assess the possible adverse effects on long-term neurodevelopment.

Consequences of prenatal substance use.

BACKGROUND: Prenatal substance use is a major public health problem and a social morbidity, with consequences on the drug user and the offspring. OBJECTIVE: This review focuses on the child and adolescent outcomes following in utero drug exposure. METHODS: Studies on the effects of specific substances, legal and illegal; i.e., tobacco or nicotine, alcohol, marijuana, cocaine, opiates, and methamphetamine were evaluated and analyzed. RESULTS: In general, manifestations of prenatal exposure to legal and illegal substances include varying deficits in birth anthropometric measurements, mild-to-moderate transient neurobehavioral alterations in infancy and long-term behavioral problems noted from early childhood to adolescence. Severity of expression of behavioral problems is influenced by environmental factors. Further, behavioral alterations following in utero drug exposure often exist with mental health co-morbidities. CONCLUSION: Because of the long-term consequences of prenatal drug exposure on child and adolescent mental health, health providers need to promote substance use prevention, screen for exposure effects and provide or refer affected youths for intervention services. Preventive measures and treatment should consider other factors that may further increase the risk of psychopathology in the exposed children.

Fumonisin FB1 treatment acts synergistically with methyl donor deficiency during rat pregnancy to produce alterations of H3- and H4-histone methylation patterns in fetuses.

SCOPE: Prenatal folate and methyl donor malnutrition lead to epigenetic alterations that could enhance susceptibility to disease. Methyl-deficient diet (MDD) and fumonisin FB1 are risk factors for neural tube defects and cancers. Evidence indicates that FB1 impairs folate metabolism. METHODS AND RESULTS: Folate receptors and four heterochromatin markers were investigated in rat fetuses liver derived from dams exposed to MDD and/or FB1 administered at a dose twice higher than the provisional maximum tolerable daily intake (PMTDI = 2 µg/kg/day). Even though folate receptors transcription seemed up-regulated by methyl depletion regardless of FB1 treatment, combined MDD/FB1 exposure might reverse this up-regulation since folate receptors transcripts were lower in the MDD/FB1 versus MDD group. Methyl depletion decreased H4K20me3. Combined MDD/FB1 decreased H4K20me3 even more and increased H3K9me3. The elevated H3K9me3 can be viewed as a defense mechanism inciting the cell to resist heterochromatin disorganization. H3R2me2 and H4K16Ac varied according to this mechanism even though statistical significance was not consistent. CONCLUSION: Considering that humans are exposed to FB1 levels above the PMTDI, this study is relevant because it suggests that low doses of FB1 interact with MDD thus contributing to disrupt the epigenetic landscape.

Embryo and fetal toxicity of Mentha x villosa essential oil in Wistar rats.

CONTEXT: Mentha x villosa Hudson (Lamiaceae) is an aromatic herb employed as a food spice. In folk medicine, it leaves are used as a tranquilizer and anti-hypertensive, even by pregnant women. OBJECTIVE: There are no reports about its effects in gestation and exposed fetuses, the aim of this study. MATERIALS AND METHODS: At gestation day (GD) 01, 24 rats were divided in four groups: one control and three experimental groups (n = 6/group). The experimental groups received, by gavage, from GD06 to GD16, 10, 25 or 50 µg/kg/day of Mentha x villosa essential oil. The control group received the vehicle (Tween 80 and distilled water--2%). The parameters of body weight gain, water and food intake were recorded. At GD20 the females were euthanized. Half of the fetuses from each litter were directed for the study of visceral malformations and the remaining fetuses for the study of skeletal malformations. RESULTS: The statistical analyses revealed absence of alterations in body weight gain, water and food intake, litter weight, fetuses number and weight, reabsorptions and implantations. The treatment revealed absence of visceral and skeletal malformations. The visceral analysis revealed mild hemorrhagic points at brain, but more numerous at kidney, liver and blood vessels near heart, in some fetuses from some experimental litters. CONCLUSION: The essential oil was not able to promote impairment to the pregnant rats and to gestation. Even occurring lack of malformations, fetotoxicity was revealed by mild hemorrhagic points at liver, kidney, brain and blood vessels of some exposed fetuses.

Neuropathology of the area postrema in sudden intrauterine and infant death syndromes related to tobacco smoke exposure.

The area postrema is a densely vascularized small protuberance at the inferoposterior limit of the fourth ventricle, outside of the blood-brain barrier. This structure, besides to induce emetic reflex in the presence of noxious chemical stimulation, has a multifunctional integrative capacity to send major and minor efferents to a variety of brain centers particularly involved in autonomic control of the cardiovascular and respiratory activities. In this study we aimed to focus on the area postrema, which is so far little studied in humans, in a large sample of subjects aged from 25 gestational weeks to 10 postnatal months, who died of unknown (sudden unexplained perinatal and infant deaths) and known causes (controls). Besides we investigated a possible link between alterations of this structure, sudden unexplained fetal and infant deaths and maternal smoking. By the application of morphological and immunohistochemical methods, we observed a significantly high incidence of alterations of the area postrema in fetal and infant victims of sudden death as compared with age-matched controls. These pathological findings, including hypoplasia, lack of vascularization, cystic formations and reactive gliosis, were related to maternal smoking. We hypothesize that components from maternal cigarette smoke, particularly in pregnancy, could affect neurons of the area postrema connected with specific nervous centers involved in the control of vital functions. In conclusion, we suggest that the area postrema should be in depth examined particularly in victims of sudden fetal or infant death with smoker mothers.

The distribution of congenital anomalies within the VACTERL association among tumor necrosis factor antagonist-exposed pregnancies is similar to the general population.

OBJECTIVE: To compare the distribution of congenital anomalies within the VACTERL association (vertebral defects, anal atresia, cardiac, tracheoesophageal, renal, and limb abnormalities) between patients exposed to tumor necrosis factor-α (TNF-α) antagonist and the general population. METHODS: Analysis for comparison of proportional differences to a previous publication between anomaly subgroups, according to subgroup definitions of the European Surveillance of Congenital Anomalies (EUROCAT), a population-based database. RESULTS: Most EUROCAT subgroups belonging to the VACTERL association contained only one or 2 records of TNF-α antagonist exposure, so comparison of proportions was imprecise. Only the category "limb abnormalities" showed a significantly higher proportion in the general population. CONCLUSION: The high number of congenital anomalies belonging to the VACTERL association from a report of pregnancies exposed to TNF-α antagonists could not be confirmed using a population-based congenital anomaly database.

Ependymal alterations in sudden intrauterine unexplained death and sudden infant death syndrome: possible primary consequence of prenatal exposure to cigarette smoking.

BACKGROUND: The ependyma, the lining providing a protective barrier and filtration system separating brain parenchyma from cerebrospinal fluid, is still inadequately understood in humans. In this study we aimed to define, by morphological and immunohistochemical methods, the sequence of developmental steps of the human ependyma in the brainstem (ventricular ependyma) and thoracic spinal cord (central canal ependyma) of a large sample of fetal and infant death victims, aged from 17 gestational weeks to 8 postnatal months. Additionally, we investigated a possible link between alterations of this structure, sudden unexplained fetal and infant death and maternal smoking. RESULTS: Our results demonstrate that in early fetal life the human ependyma shows a pseudostratified cytoarchitecture including many tanycytes and ciliated cells together with numerous apoptotic and reactive astrocytes in the subependymal layer. The ependyma is fully differentiated, with a monolayer of uniform cells, after 32 to 34 gestational weeks. We observed a wide spectrum of ependymal pathological changes in sudden death victims, such as desquamation, clusters of ependymal cells in the subventricular zone, radial glial cells, and the unusual presence of neurons within and over the ependymal lining. These alterations were significantly related to maternal smoking in pregnancy. CONCLUSIONS: We conclude that in smoking mothers, nicotine and its derivatives easily reach the cerebrospinal fluid in the fetus, immediately causing ependymal damage. Consequently, we suggest that the ependyma should be examined in-depth first in victims of sudden fetal or infant death with mothers who smoke.

Cleft lip and palate results from Hedgehog signaling antagonism in the mouse: Phenotypic characterization and clinical implications.

BACKGROUND: The Hedgehog (Hh) pathway provides inductive signals critical for developmental patterning of the brain and face. In humans and in animal models interference with this pathway yields birth defects, among the most well-studied of which fall within the holoprosencephaly (HPE) spectrum. METHODS: Timed-pregnant C57Bl/6J mice were treated with the natural Hh signaling antagonist cyclopamine by subcutaneous infusion from gestational day (GD) 8.25 to 9.5, or with a potent cyclopamine analog, AZ75, administered by oral gavage at GD 8.5. Subsequent embryonic morphogenesis and fetal central nervous system (CNS) phenotype were respectively investigated by scanning electron microscopy and high resolution magnetic resonance imaging (MRI). RESULTS: In utero Hh signaling antagonist exposure induced a spectrum of craniofacial and brain malformations. Cyclopamine exposure caused lateral cleft lip and palate (CLP) defects attributable to embryonic deficiency of midline and lower medial nasal prominence tissue. The CLP phenotype was accompanied by olfactory bulb hypoplasia and anterior pituitary aplasia, but otherwise grossly normal brain morphology. AZ75 exposure caused alobar and semilobar HPE with associated median facial deficiencies. An intermediate phenotype of median CLP was produced infrequently by both drug administration regimens. CONCLUSIONS: The results of this study suggest that interference with Hh signaling should be considered in the CLP differential and highlight the occurrence of CNS defects that are expected to be present in a cohort of patients having CLP. This work also illustrates the utility of fetal MRI-based analyses and establishes a novel mouse model for teratogen-induced CLP.

First trimester curtailment of iron absorption: innate suppression of a teratogen?

In human pregnancies, maternal absorption of iron is markedly curtailed in the first trimester. In a murine model, iron was teratogenic in the analogous embryonic period. Although iron is a weak mutagen, it is a powerful oxidant and a catalyst of formation of hydroxyl radicals. Studies are needed to determine if there might be an association of first trimester iron supplementation with miscarriage/fetal abnormalities.

6-mercaptopurine (6-MP) induces p53-mediated apoptosis of neural progenitor cells in the developing fetal rodent brain.

6-mercaptopurine (6-MP), a DNA-damaging agent, induces apoptosis of neural progenitor cells, and causes malformation in the fetal brain. The aim of the present study is to clarify the molecular pathway of 6-MP-induced apoptosis of neural progenitor cells in the fetal telencephalon of rats and mice. p53 protein is activated by DNA damage and induces apoptosis through either the intrinsic pathway involving the mitochondria or the extrinsic pathway triggered by death receptors. In this study, the expression of puma and cleaved caspase-9 proteins, which are specific intrinsic pathway factors, increased in the rat telencephalon after 6-MP treatment. 6-MP-induced apoptosis of neural progenitor cells was completely absent in p53-deficient mice. On the other hand, the expression of Fas protein, an extrinsic pathway factor, did not change throughout the experimental period in the rat telencephalon treated with 6-MP. The number of apoptotic neural progenitor cells was similar among Fas-mutated lpr/lpr and wild-type mice, suggesting that the Fas pathway does not play a significant role in 6-MP-induced apoptosis of neural progenitor cells. These results may suggest that the p53-mediated intrinsic pathway is essential for 6-MP-induced apoptosis of neural progenitor cells in the developing telencephalon of rats and mice.

Reversal of heroin neurobehavioral teratogenicity by grafting of neural progenitors.

A major objective in identifying the mechanisms underlying neurobehavioral teratogenicity in an animal model is the possibility of designing therapies that reverse or offset teratogen-induced neural damage. In our previous studies, we identified deficits in hippocampal muscarinic cholinergic receptor-induced translocation of protein kinase C (PKC) gamma as the likely central factor responsible for the adverse behavioral effects of pre-natal heroin exposure. Neural progenitors (NP) have the ability to recover behavioral deficits after focal hippocampal damage. Therefore, we explored whether behavioral and synaptic defects could be reversed in adulthood by neural progenitor grafting. Pregnant mice were injected daily with 10 mg/kg of heroin on gestational days 9-18. In adulthood, offspring showed deficits in the Morris maze, a behavior dependent on the integrity of septohippocampal cholinergic synaptic function, along with the loss of the PKCgamma and PKCbetaII responses to cholinergic stimulation. Mice that were exposed pre-natally to heroin and vehicle control mice were then grafted in adulthood with NP. Importantly, most grafted cells differentiated to astrocytes. NP reversed the behavioral deficits (p = 0.0043) and restored the normal response of hippocampal PKCgamma and PKCbetaII (p = 0.0337 and p = 0.0265 respectively) to cholinergic receptor stimulation. The effects were specific as the PKCalpha isoform, which is unrelated to the behavioral deficits, showed almost no changes. Neural progenitor grafting thus offers an animal model for reversing neurobehavioral deficits originating in septohippocampal cholinergic defects elicited by pre-natal exposure to insults.