Do Autistic and Depressed Rats Express the Same Type of Maternal Care?

Autism is a neurodevelopmental disorder that is more frequently diagnosed in men. Nevertheless, through current diagnostic tools, women have also been found to be affected by this disorder, but in different ways. Few studies have been conducted regarding unique periods of life, such as motherhood. Yet, extant literature has already described the existence of a comorbidity between autism and postpartum depression. Thus, this study aimed to compare the maternal care sphere between two animal models of these diseases. Lactating rats were subdivided into three groups (n = 8 animals/group): 1) control dams; 2) maternal separation (MS) dams, separated from their litter for 3 h daily from lactating day (LD) 2-12 for postpartum depression induction; and 3) valproic acid (VPA) dams, which were the pups of dams treated with 400 mg/kg of VPA (i.p.) on gestational day 12.5 for autism induction. Maternal care tests were performed during lactation and, after weaning, dams were euthanized for the analysis of dopaminergic system on the prefrontal cortex. The results showed an impairment of maternal care of MS dams and an improvement of VPA dams, as well as alterations on dopaminergic system that corroborates the behavior data. These findings indicate that VPA dams express better maternal care, even with cognitive and socialization difficulties. This is probably due to a hyper-focus, as opposed to MS dams, which mimic the maternal care dysfunction expressed by women with postpartum depression.

Effects of ivermectin treatment during prepubertal and pubertal period on sexual parameters and sexual behavior in adulthood in rats.

Pediculosis is a parasitic disease that is considered a serious global public health problem. It is caused by the ectoparasite that is popularly known as lice, mainly affecting children in early childhood. The most commonly used treatment to combat this parasitosis is the macrocyclic lactone ivermectin (IVM). However, the use of IVM is contraindicated in children who are younger than 5 years old or who weigh <15 kg because some types of drugs that are used during certain periods of brain maturation can lead to behavioral disorders. The present study evaluated the effects of IVM treatment during the prepubertal and pubertal period on sexual behavior in adulthood in male rats. Genital grooming, preputial separation, sexual behavior, sexual motivation, relative organ weight, the gonadosomatic index, and histopathology were evaluated. Oral dose of 0.2 mg/kg (therapeutic dose) of a commercial IVM formulation was administered. IVM affected genital grooming but did not influence preputial separation in prepubertal rats. Prepubertal IVM administration did not impair sexual behavior in adult rats, with the exception of the time of residence with female rats in the sexual motivation test. It did not affect relative organ weights, with the exception of the relative weight of the full seminal vesicle. It did not alter the gonadosomatic index, and no histopathological alterations were observed in different organs. These results indicate that administration of a therapeutic dose of IVM during the prepubertal and pubertal period does not alter parameters of sexual development or sexual behavior in adult male rats.

Ivermectin does not interfere with seminal and hormonal parameters in male rabbits.

Ivermectin (IVM) is a macrocyclic lactone used as a broad spectrum antiparasitic agent against nematodes and arthropods. It is mainly used in the control of parasitic infections of domestic animals, and recently has been used in humans to treat onchocerciasis, scabies, and pediculosis. In mammals, evidence has indicated that macrocyclic lactones interact with gamma-aminobutyric acid (GABA)-mediated chloride channels. The GABAergic system is known to be involved in the manifestation of sexual behavior, and previous studies have shown that IVM impaired sexual behavior in both male and female rats. Thus, considering that IVM may interfere with the sexual sphere, this study evaluated the temporal (1 up 60 days) effects of exposure to IVM (0.2 and 1.0 mg/kg, administered subcutaneously) on seminal and hormonal parameters of male rabbits. In male rabbits, the spermatozoa concentration, motility and morphology, the integrity of the plasmatic, acrosomal and mitochondrial membranes of the spermatozoa, the organ weights, gonadosomatic index, serum testosterone concentrations, histopathological findings were evaluated and hematological and serum biochemical analysis was conducted. No changes were observed in male seminal parameters evaluated by spermatozoa concentration, motility, and morphology, nor the potential for fertilization evaluated by the integrity of the plasmatic, acrosomal, and mitochondrial membranes of the spermatozoa; there was also no interference in serum testosterone concentration, serum biochemistry and hematological parameters. The findings of this study using the artificial vagina for collection of semen and computer-assisted semen analysis showed that IVM at doses of 0.2 and 1.0 mg/kg of SC did not alter any of the semen parameters of rabbits evaluated for up to 60 days after administration.

Ivermectin reduces motor coordination, serum testosterone, and central neurotransmitter levels but does not affect sexual motivation in male rats.

Ivermectin (IVM) is a macrocyclic lactone used for the treatment of parasitic infections and widely used in veterinary medicine as endectocide. In mammals, evidence indicates that IVM interacts with γ-aminobutyric acid (GABA)-mediated chloride channels. GABAergic system is involved in the manifestation of sexual behavior. We previously found that IVM at therapeutic doses did not alter sexual behavior in male rats, but at a higher dose, the appetitive phase of sexual behavior was impaired. Thus, we investigated whether the reduction of sexual behavior that was previously observed was a consequence of motor or motivational deficits that are induced by IVM. Data showed significant decrease in striatal dopaminergic system activity and lower testosterone levels but no effects on sexual motivation or penile erection. These findings suggest IVM may activate the GABAergic system and reduce testosterone levels, resulting in a reduction of motor coordination as consequence of the inhibition of striatal dopamine release.

Rats exposed to Solanum lycocarpum fruit in utero and during lactation: neurochemical, behavioral and histopathological effects.

Solanum lycocarpum St. Hil (Solanaceae) is a native shrub very common in the Brazilian savannah. This plant contains steroidal glycoalkaloids that can be transformed into an intermediate for steroidal drug production. In this way, it is very possible that these glycoalkaloids and its aglycone, once in the body by ingestion of S. lycocarpum fruits, may act by disrupting the endocrine system. Because its fruits may be consumed by pregnant animals in the fields, the present study determined the possible toxic effects of exposure to S. lycocarpum fruit (10% added in the diet) from gestation day (GD) 6 to postnatal day (PND) 07 in rat dams. The unripe fruits contained 0.6% of solamargine and 0.9% of solasonine. S. lycocarpum, 10% in the diet, during gestation and the beginning of lactation reduced intrauterine growth. In addition, 20% of the treated dams showed some dead pups at birth. Reduced body weight was observed from birth through adulthood in male and female offspring exposed to 10% S. lycocarpum unripe fruits. During adulthood, female offspring showed impaired sexual behavior and male offspring showed prominent degeneration of testis germinative cells, characterized by a reduced number of germ cells and vacuolation. Also, the exposed offspring showed reduced hypothalamic norepinephrine (NOR), vanillylmandelic acid (VMA), 3-methoxy-4-hydrophenylglycol (MHPG) and homovanillic acid (HVA) levels, and reduced striatum NOR, HVA, VMA, MHPG, dopamine (DA), dihydroxyphenylacetic acid (DOPAC) and 5-hydroxyindolacetic acid (5-HIAA) levels. These results suggest that the fruit may act as an estrogen, with a long-term effect, impairing the receptive lordosis behavior of female offspring and promoting testis abnormalities in male offspring at adulthood. Finally, it appears to disrupt brain organization since important central monoamine level alterations were also observed.

Behavioral and endocrine changes induced by perinatal fenvalerate exposure in female rats.

Pyrethroid insecticides have recently been linked to endocrine disruption. Endocrine disrupting chemicals have been defined as exogenous agents that interfere with the synthesis, secretion, binding, action, or elimination of natural hormones in the body. Previous research conducted in our laboratory suggests that perinatal exposure to fenvalerate, a type-II pyrethroid, interferes with brain sexual organization in male pups, probably acting on a critical perinatal hormone-related period. In the present study we investigate the effects of maternal exposure to fenvalerate (FV) during the prenatal and postnatal periods of sexual brain organization of female offspring. Behavioral (open-field, stereotyped and sexual behaviors), physical (sexual maturation, body and uterine weights), and neuroendocrine (estrous cycle and gonadal hormone levels ) parameters were assessed. Results show that 1) sexual maturation was delayed, albeit body weight was unchanged until adulthood; 2) there was a reduction in sexual behavior; 3) the estrous cycle was abnormal, and the uterine weight at different phases of the estrous cycle was modified; 4) gonadal hormone levels in the plasma were not affected, neither was stereotypy nor open-field behaviors. These results were attributed to an anti-estrogenic effect of perinatal exposure to FV during the critical periods of female brain sexual organization.

Comparative effects of maternal prenatal and postnatal exposures to astemizole on reproductive parameters of rats.

The prenatal and postnatal effects of administration of a nonsedative antihistamine H1, astemizole (ATZ), were compared. ATZ (10 mg/kg) was injected daily into female Wistar rats throughout pregnancy (prenatal treatment) or during the first 6 days of lactation (postnatal treatment). Neither treatment modified dam body weight. Prenatal exposure reduced offspring body weight and lead to a latter expression of the vaginal opening of female offspring. In addition, a long-term disruption of male reproductive behavior was observed, while female sexual behavior was not modified. The sexual activity index and the intromission frequency were increased in prenatally treated animals. Testes wet weight was reduced, but no modifications were detected in vas deferens or seminal vesicles. Postnatal treatment did not alter offspring body weight, open-field activity, sexual behavior and organ weight as well as did not delay testes descent but reduced the time until vaginal opening. Hypothalamic serotonin (5-HT), dopamine (DA) and noradrenaline (NA) as well as DA and NA metabolites were not modified by both prenatal and postnatal treatments. Increased striatal 3,4-dihydroxyphenylacetic acid (DOPAC) levels were observed after prenatal and postnatal treatments, while only postnatal 5-HT levels were increased. We propose that the present results indicate that prenatal ATZ exposure can have long-lasting organizational effects on reproductive behavior of male rats, while postnatal exposure to this drug did not alter mating behavior. In relation to female rats, prenatal and postnatal exposures to ATZ accelerated puberty but did not alter sexual behavior. Neurochemical data show that both treatments increased striatal dopaminergic system activity, suggesting a central ATZ effect after perinatal exposure.

Embryotoxic and long-term effects of cadmium exposure during embryogenesis in rats.

The present study was performed to evaluate the long-term behavioral effect in offspring of a subteratogenic Cd dose administered by the oral route to Wistar rat during organogenesis. First, the teratogenic Cd dose was determined by treating pregnant rats with 20 mg/kg Cd from Day 6 to Day 14 of pregnancy and by visceral and skeletal analysis of their fetuses. In a second experiment, pregnant rats treated with this Cd dose were allowed to give birth and nurture their offspring. The physical and behavioral parameters of the offspring were analyzed in infancy and during adulthood. Results showed that Cd treatment during organogenesis (1) was not able to induce maternal toxicity; (2) induced external malformations; (3) increased significantly fetus anomalies and malformations, with reduced metacarpus ossification, cleft palate and right or left renal cavitation being observed in these animals; (4) did not modify pup body weight or weight gain during the lactation period; (5) improved testis descent and delayed the vaginal opening of pups; (6) did not modify ear unfolding, incisor eruption, eye opening, negative geotaxis or palmar grasp; (7) did not modify the open-field parameters and the stereotyped behavior of male or female pups; and (8) modified male sexual behavior and (9) reduced female sexual behavior. We conclude that prenatal exposure to a teratogenic Cd dose induced in the survivor animals several deleterious effects in their development as well as in adult behaviors, mainly in the sexual sphere.

Maternal exposure to diphenhydramine during the fetal period in rats: effects on physical and neurobehavioral development and on neurochemical parameters.

Previous research from our laboratory suggested that the administration of antihistaminics (H(1) receptor antagonists) to pregnant Wistar rats throughout pregnancy altered brain sexual differentiation and dopaminergic physiology of the offspring. In the present study, we assessed the effects of 20 mg/kg diphenhydramine (DPH) administration to pregnant rats during the fetal period of pregnancy [Gestation Days (GDs) 16-21], a critical period for brain sexual differentiation and central nervous system (CNS) maturation. Maternal body weight and water and food consumption were measured during pregnancy and offspring physical and behavioral development were evaluated during lactation. Offspring open-field behavior was assessed at 21 and 100 days of age. After the final open-field test, male and female sexual behavior, stereotypy following an apomorphine challenge, striatal content of dopamine (DA), the dopamine metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanilic acid (HVA), serotonin (5-HT) and the serotonin metabolite 5-hydroxyindolacetic acid (5-HIAA) were assessed. There were no significant treatment-related changes in maternal reproductive parameters, but DPH treatment decreased maternal body weight gain during the treatment period. Offspring physical parameters were not altered in the treated group, and no significant treatment-related changes were found in female open-field measures, sexual behavior or in striatal neurochemical measurements. However, delayed testis descent and altered patterns of sexual behavior occurred in male offspring accompanied by increased striatal DA, decreased striatal DOPAC as well as reduced DOPAC/DA, HVA/DA and 5-HIAA/5-HT ratios. Taken together, these data suggest that exposure to DPH during the fetal period of rat development altered postnatal CNS maturation and sexual development of male offspring via changes in striatal bioamine systems.

Effects of Ipomoea carnea aqueous fraction intake by dams during pregnancy on the physical and neurobehavioral development of rat offspring.

The effects of daily prenatal exposure to 0.0, 0.7, 3.0 and 15.0 mg/kg of the aqueous extract (AQE) of Ipomoea carnea dried leaves on gestational days 5-21 were studied in rat pups and adult offspring. The physical and reflex developmental parameters, open-field, plus-maze, social interaction, forced swimming, catalepsy and stereotyped behaviors, as well as striatal, cortical and hypothalamic monoamine levels (at 140 days of age) were measured. Maternal and offspring body weights were unaffected by exposure to the different doses of the AQE. High postnatal mortality, smaller size at Day 1 of life, reversible hyperflexion of the carpal joints and delay in the opening of both ears and in negative geotaxis were observed in the offspring exposed to the higher dose of AQE. At 60 and 90 days of age, open-field locomotion frequency was quite different between 0.0 and animals treated with 0.7 and 3.0 mg/kg AQE. No changes were observed in the plus-maze, social interaction, forced swimming, catalepsy, stereotyped behavior and central nervous system monoamines concentrations. Dams treated with the higher AQE dose showed severe cytoplasmic vacuolation in liver, kidney, pancreas and thyroid tissues, in contrast to the mild vacuolation observed in the other experimental groups. No alterations were observed in the histopathological study of the offspring of all experimental groups at 140 days of age. During adulthood, behavior was not modified in offspring exposed to the higher dose of AQE as well as no changes occurred in central nervous system neurotransmitters. The present data show that the offspring development alterations were not severe enough to produce behavioral and central monoamine level changes.

Embryotoxic effects of Solanum lycocarpum St. Hill fruits consumption during preimplantation and organogenesis in rats.

Solanum lycocarpum St. Hill is a common plant in the Brazilian savanna. This plant has an alkaloid with stereospecific configuration to the synthesis of steroid hormones. Since the plant may be consumed by pregnant animals, the present study was undertaken to determine the possible embryotoxic effects of S. lycocarpum fruit ingestion (3% added to the diet) during preimplantation (from the first to the sixth days of gestation) or during organogenesis in rats (from the sixth to the sixteenth days of gestation). Few differences were observed in food and water consumption without biological importance. The placental weight in the group that received the plant during the organogenesis period was decreased. An increase in sternebra abnormalities was observed in animals treated with the plant during organogenesis. Olfactory bulb hemorrhage was increased in the group that received the plant during preimplantation when compared to the control group. These results indicate that consumption of S. lycocarpum at 3% in diet during pregnancy cause slight toxicological effects. Other studies have to be conducted to better investigate the causes of toxicity and other toxic effects of higher levels of exposure to this plant.

Role of early GnRH administration in sexual behavior disorders of rat pups perinatally exposed to lead.

The effects of maternal exposure to lead (Pb) during the perinatal (1% and 0.1% Pb) periods of sexual brain differentiation were studied in adult male offspring. Maternal Pb levels were measured after treatment. Behavioral (open field and sexual behavior), physical (sexual maturation, body and organ weights), and biochemical (testosterone levels and hypothalamic monoamine and respective metabolite levels) data were assessed in perinatally exposed offspring. The effects of gonadrotopin-releasing hormone (GnRH) administration to pups at birth on puberty and sexual behavior were also investigated in offspring postnatally exposed to the metal. Results showed that perinatal administration of the two Pb concentrations did not modify maternal weight gain; 1% Pb exposure reduced offspring body weight during the 7 days of treatment while no changes were observed after 0.1% Pb exposure; neither Pb concentration altered offspring sexual maturation; the higher Pb concentration improved sexual behavior while the 0.1% concentration reduced it; exposure to 0.1% Pb caused decrease in testis weight, an increase in seminal vesicle weight and no changes in plasma testosterone levels; hypothalamic VMA levels were increased compared to the control group; GnRH administration reversed the effects of 0.1% Pb administration on male sexual behavior. These results show that perinatal exposure to Pb had a dose-dependent effect on the sexual behavior of rats and that a decrease in GnRH source in the offspring was probably involved in the reduction of their sexual performance.

Perinatal fenvalerate exposure: behavioral and endocrinology changes in male rats.

The effects of maternal exposure to fenvalerate during the prenatal and postnatal periods of sexual brain differentiation were studied in adult male offspring. Behavioral (open field, stereotyped, and sexual behaviors), physical (sexual maturation, body and organ weights), endocrine (testosterone levels), and neurochemical (striatal and hypothalamic monoamine and respective metabolite levels) data were assessed. The results showed that there was no change in the age of testis descent or testis weight, nor were there changes in monoamine levels or stereotyped behavior. However, there were significant reductions in ductus deferens and seminal vesicle weights and plasma testosterone concentrations. In addition, treated offspring showed decreased male sexual behavior and increased immobility in the open field. These results indicate that perinatal exposure to fenvalerate during the critical periods of male brain sexual differentiation has long-term effects on the reproductive physiology and behavior of male rats.

Effects of exposure to a pyrethroid insecticide during lactation on the behavior of infant and adult rats.

Cyhalothrin, a pyrethroid insecticide, was administered to female Wistar rats as a 0.02% solution plus 0.04% sucrose (w/v) in drinking water from whelping to pup weaning after 21 days of lactation. The pesticide did not change the maternal behavior of the dams as measured by the scoring system of Soderstein and Eneroth. The body weight of pups exposed to the pesticide and at age 90 days was not different from that of controls, and the motor activity of the pups measured in a simple photocell activity cage was not affected by pesticide treatment. Furthermore, no overt signs of neural toxicity were observed in the offspring. However, the treatment disrupted rat behavior in adulthood when assessed by using an inhibitory avoidance learning task. Thus, inhibitory avoidance tests carried out on rats at 90 days of age were capable of demonstrating neural toxicity of Cyhalothrin (0.02%) present only in the drinking water of dams during 21 days of lactation.

Perinatal astemizole exposure in the rat throughout gestation: long-term behavioral and anatomic effects associated with reproduction.

Astemizole (ATZ), a non-sedative antihistamine, which antagonize histamine at the level of H1 receptor, was administered daily to female Wistar rats as a 10-mg/kg dose throughout pregnancy. ATZ exposure reduced offspring body weight and delayed the pinna detachment and startle reflex without any modification of dams body weight during gestation. Long-term disruption of male reproductive behavior was seen in experimental animals, whereas female sexual behavior was not modified. In addition, no motor alterations were observed in female or males in adulthood. Testis wet weight was reduced, but no modifications were detected in vasa deferentia or seminal vesicle. We proposed that ATZ administration during pregnancy causes several effects mainly of a sexual nature by interfering either with the hormonal mechanism involved in the central nervous system masculinization or by a direct action of the drug on pups during the development.

The use of ELISA tests and immunoaffinity chromatography combined with reversed-phase high-performance liquid chromatography for dexamethasone detection in equine urine.

Dexamethasone is a corticosteroid drug widely used in racehorses because of its anti-inflammatory effect. It is, therefore, frequently detected in antidoping tests. A method for the antidoping control of dexamethasone in equine urine using screening by ELISA and confirmation by immunoaffinity chromatography combined with reversed-phase high-performance liquid chromatography-diode array detection (HPLC-DAD) is described. The ELISA test is frequently used in antidoping tests for its sensitivity, relative speed, and low cost. The test showed linearity in the range of 4-500 ng/mL of urine, and the intra-assay and interassay imprecision were 9.4 and 9.7%, respectively. The confirmation method showed a limit of detection of 4 ng/mL for dexamethasone. The intra-assay and interassay imprecisions were 10.3 and 14.4%, respectively. The HPLC-DAD showed a limit of detection of 5 ng and linearity in the range of 25-500 ng of dexamethasone. The absolute method recovery was 56.4%. The proposed method detected dexamethasone up to 52 h after administration and proved to be adequate for the antidoping control.

Immunoaffinity chromatography in the detection of dexamethasone in equine urine.

Due to the widespread use of dexamethasone in racing horses, mostly in low doses by intra-articular administration for the treatment of inflammatory processes, a method is developed to detect this drug in horse urine samples using liquid-liquid extraction followed by immunoaffinity chromatography. Liquid chromatography with diode-array detection is used for the identification of the drug. The use of immunoaffinity columns enhances the selectivity of the analysis, and the results show that dexamethasone can be detected up to 28 h after intra-articular administration.

Hydrocortisone concentrations in post-race urine from horses.

As hydrocortisone is an endogenous substance, it is first necessary to establish its normal concentrations so as to be able to control its use in racing animals. This study was designed to establish the hydrocortisone concentrations in post-race urine samples of horses racing in Brazil and also to evaluate the results in relation to the international threshold set for this drug. Urine samples were analysed by HPLC-UV. The results were evaluated according to the concentration range as well as sex and time of sample collection (afternoon or evening races). The results showed a high degree of variation in the concentrations of hydrocortisone in the urine (93 +/- 69 ng/ml). The maximum concentration observed was 646 ng/ml, although only a few horses (around 1%) showed levels within the range 500-650 ng/ml, 91% being in the range 0-150 ng/ml. The data suggested a normal distribution curve. Statistical analysis showed no significant influence of sex or time of sample collection.

The clinical, biochemical, haematological and pathological effects of long-term administration of Ipomoea carnea to growing goats.

Ipomoea carnea has been held responsible for several poisoning episodes, mainly in goats. This plant contains swainsonine, which inhibits acid or lysosomal alpha-mannosidase enzyme, causing cellular vacuolization. The objective of this study was to evaluate I. carnea toxicosis when four different doses of this plant were fed to growing goats. Twenty-five male goats were divided into five groups, one control group and four experimental groups that received 2.5, 5.0, 10.0 and 30.0 g of the plant per kg of live weight per day for 4 months. Blood samples were collected for haematological and biochemical determinations and fragments from some tissues were collected for histopathological study. All the experimental goats ingested the plant throughout the trial, presenting nystagmus, muscle tremors, weakness of the hind limbs and ataxia. They also had a significant increase in alanine aminotransferase (ALT) from the sixth week of the experiment compared to the goats in the control group. There was a significant reduction in haemoglobin concentration in the goats treated with I. carnea. Histopathology revealed degenerative vacuolar alterations in the liver, pancreas, thyroid and kidney cells, and in the neurons of the central nervous system in the animals that received the plant. All these alterations occurred in a dose-dependent manner.

Ivermectin reduces sexual behavior in female rats.

Ivermectin (IVM) is an antiparasitic drug that is widely used in domestic animals. In mammals, IVM acts as a γ-aminobutyric acid (GABA) receptor agonist. This neurotransmitter plays an important role in the regulation of female sexual behavior. The present study investigated the effects of therapeutic (0.2 mg/kg) and high (1.0 mg/kg) IVM doses on female sexual behavior in physiological and pharmacological conditions. Female rats in estrus or treated with estradiol valerate to induce sexual behavior 24 h before the experiments were used. Ivermectin was administered 15 min before the sexual observations. The number of lordosis events in 10 mounts was recorded to calculate the lordosis quotient. The intensity of lordosis (0 [no lordosis], 1 [low lordosis], 2 [normal lordosis] and 3 [exaggerated lordosis]) was scored. In estrus and hormonal treated female rats, both IVM doses decreased the intensity of the lordosis reflex and the percentage of females that presented high levels of lordosis (exaggerated lordosis). However, the number of females that presented lordosis was unaltered. We conclude that in both hormonal conditions, 0.2mg/kg IVM treatment reduced female sexual behavior and the execution of the lordosis reflex. The present results may be useful for avoiding the side effects of this drug in veterinary practice.