Microencapsulation of sunscreen reduces toxicity of its components to A. salina: Biochemical, behavioral and morphological studies.

Sunscreens contain several substances that cause damage to species where they are disposed. New formulations have been created to prevent such marine environmental damages. One promising formulation is the microencapsulated sunscreen. The objective of this study was to evaluate the possible safety to marine environment of one microencapsulated sunscreen formulation. The animal model Artemia salina (cists and nauplii) was tested with two sunscreen formulations (microencapsulated and non-microencapsulated) and toxicological, behavioral, morphological parameters as well as biochemical assays (lipoperoxidation and carbonylation tests) were analyzed. Results showed that microencapsulated sunscreen impeded some toxic effects caused by the release of the substances within the microcapsule in the highest concentration, reestablishing the mortality and hatching rates to control levels, while removing the sunscreen microcapsule by adding 1 % DMSO reduced the cyst hatching rate, increasing the nauplii mortality rate and decreased locomotor activity in higher concentrations. Finally, nauplii with 24 hours of life and exposed to sunscreen without the microcapsule showed an increase in mitochondrial activity (assessed at 48 hours after exposure) and presented malformations when exposed to the highest concentration non-microencapsulated concentration (assessed by SEM at 72 hours after exposure), when compared to the control group. These results together allow us to conclude that the microencapsulation process of a sunscreen helps protecting A. salina from the harmful effects of higher concentrations of said sunscreens. However, long-term studies must be carried out as it is not known how long a microencapsulated sunscreen can remain in the environment without causing harmful effects to the marine ecosystem and becoming an ecologically relevant pollutant.

Multisensory Stimulation Reverses Memory Impairment in Adrß3KO Male Mice.

Norepinephrine plays an important role in modulating memory through its beta-adrenergic receptors (Adrß: ß1, ß2 and ß3). Here, we hypothesized that multisensory stimulation would reverse memory impairment caused by the inactivation of Adrß3 (Adrß3KO) with consequent inhibition of sustained glial-mediated inflammation. To test this, 21- and 86-day-old Adrß3KO mice were exposed to an 8-week multisensory stimulation (MS) protocol that comprised gustatory and olfactory stimuli of positive and negative valence; intellectual challenges to reach food; the use of hidden objects; and the presentation of food in ways that prompted foraging, which was followed by analysis of GFAP, Iba-1 and EAAT2 protein expression in the hippocampus (HC) and amygdala (AMY). The MS protocol reduced GFAP and Iba-1 expression in the HC of young mice but not in older mice. While this protocol restored memory impairment when applied to Adrß3KO animals immediately after weaning, it had no effect when applied to adult animals. In fact, we observed that aging worsened the memory of Adrß3KO mice. In the AMY of Adrß3KO older mice, we observed an increase in GFAP and EAAT2 expression when compared to wild-type (WT) mice that MS was unable to reduce. These results suggest that a richer and more diverse environment helps to correct memory impairment when applied immediately after weaning in Adrß3KO animals and indicates that the control of neuroinflammation mediates this response.

Highly Diluted Glyphosate Mitigates Its Effects on Artemia salina: Physicochemical Implications.

Glyphosate is an herbicide widely used in agriculture but can present chronic toxicity in low concentrations. Artemia salina is a common bio-indicator of ecotoxicity; it was used herein as a model to evaluate the effect of highly diluted-succussed glyphosate (potentized glyphosate) in glyphosate-based herbicide (GBH) exposed living systems. Artemia salina cysts were kept in artificial seawater with 0.02% glyphosate (corresponding to 10% lethal concentration or LC10) under constant oxygenation, luminosity, and controlled temperature, to promote hatching in 48 h. Cysts were treated with 1% (v/v) potentized glyphosate in different dilution levels (Gly 6 cH, 30 cH, 200 cH) prepared the day before according to homeopathic techniques, using GBH from the same batch. Controls were unchallenged cysts, and cysts treated with succussed water or potentized vehicle. After 48 h, the number of born nauplii per 100 µL, nauplii vitality, and morphology were evaluated. The remaining seawater was used for physicochemical analyses using solvatochromic dyes. In a second set of experiments, Gly 6 cH treated cysts were observed under different degrees of salinity (50 to 100% seawater) and GBH concentrations (zero to LC 50); hatching and nauplii activity were recorded and analyzed using the ImageJ 1.52, plug-in Trackmate. The treatments were performed blind, and the codes were revealed after statistical analysis. Gly 6 cH increased nauplii vitality (p = 0.01) and improved the healthy/defective nauplii ratio (p = 0.005) but delayed hatching (p = 0.02). Overall, these results suggest Gly 6cH treatment promotes the emergence of the more GBH-resistant phenotype in the nauplii population. Also, Gly 6cH delays hatching, another useful survival mechanism in the presence of stress. Hatching arrest was most marked in 80% seawater when exposed to glyphosate at LC10. Water samples treated with Gly 6 cH showed specific interactions with solvatochromic dyes, mainly Coumarin 7, such that it appears to be a potential physicochemical marker for Gly 6 cH. In short, Gly 6 cH treatment appears to protect the Artemia salina population exposed to GBH at low concentrations.

Bioresilience to Mercury Chloride of the Brine Shrimp Artemia Salina after Treatment with Homeopathic Mercurius Corrosivus.

INTRODUCTION: Finding solutions to mitigate the impact of pollution on living systems is a matter of great interest. Homeopathic preparations of toxic substances have been described in the literature as attenuation factors for intoxication. Herein, an experimental study using Artemia salina and mercury chloride was developed as a model to identify aspects related to bioresilience. AIMS: The aim of the study was to describe the effects of homeopathic Mercurius corrosivus (MC) on Artemia salina cysts hatching and on mercury bioavailability. METHODS: Artemia salina cysts were exposed to 5.0 µg/mL of mercury chloride during the hatching phase. MC potencies (6cH, 30cH, and 200cH) were prepared in sterile purified water and poured into artificial sea water. Different controls were used (non-challenged cysts and challenged cysts treated with water, succussed water, and Ethilicum 1cH). Four series of nine experiments were performed to evaluate the percentage of cyst hatching. Soluble total mercury (THg) levels and precipitated mercury content were also evaluated. Solvatochromic dyes were used to check for eventual physicochemical markers of MC biological activity. RESULTS: Significant delay (p < 0.0001) in cyst hatching was observed only after treatment with MC 30cH, compared with controls. This result was associated with an increase of THg concentration in water (p = 0.0018) and of chlorine/oxygen ratio (p < 0.0001) in suspended micraggregates, suggesting changes in mercury bioavailability. A specific interaction of MC 30cH with the solvatochromic dye ET33 (p = 0.0017) was found. CONCLUSION: Changes in hatching rate and possible changes in Hg bioavailability are postulated as protective effects of MC 30cH on Artemia salina, by improving its natural bioresilience processes.

Zinc, but not paracetamol, prevents depressive-like behavior and sickness behavior, and inhibits interferon-gamma and astrogliosis in rats.

Considering all mental and addictive disorders, depression is the most responsible for years of life lost due to premature mortality and disability. Antidepressant drugs have limited effectiveness. Depression can be triggered by immune/inflammatory factors. Zinc and paracetamol interfere with immune system and have demonstrated beneficial effects on depression treatment when administered concomitant with antidepressant drugs. The objective of this study was to test zinc and/or paracetamol as treatments of depressive-like behavior, sickness behavior, and anxiety in rats, as well as to understand the central and peripheral mechanisms involved. Sickness behavior and depressive-like behavior were induced in rats with repetitive lipopolysaccharide (LPS, 1 mg/kg for two consecutive days) administrations. Rats received zinc and/or paracetamol for three consecutive days. Sickness behavior (daily body weight and open field general activity); anxiety (light-dark test); depressive-like/antidepressant behavior (forced swim test); plasma corticosterone and interferon (IFN)-gamma levels; and glial fibrillary acidic protein (GFAP) and tyrosine hydroxylase (TH) brain expression were evaluated. LPS induced sickness behavior and depressive-like behavior, as well as elevated IFN-gamma levels and increased GFAP expression. Zinc prevented both behavioral and biochemical impairments. Paracetamol and zinc + paracetamol association induced only slight beneficial effects. Anxiety, corticosterone, and TH do not seem be related with depression and the other behavioral and neuroimmune changes. In conclusion, zinc treatment was beneficial for sickness behavior and depressive-like behavior without concomitant administration of antidepressants. IFN-gamma and GFAP were linked with the expression of sickness behavior and depressive-like behavior and were also involved with the antidepressant effects. Therefore, zinc, IFN-gamma, and GFAP pathways should be considered for depression treatment.

Behavioral and neurochemical characterization of the spontaneous mutation tremor, a new mouse model of audiogenic seizures.

The tremor mutant phenotype results from an autosomal recessive spontaneous mutation arisen in a Swiss-Webster mouse colony. The mutant mice displayed normal development until three weeks of age when they began to present motor impairment comprised by whole body tremor, ataxia, and decreased exploratory behavior. These features increased in severity with aging suggesting a neurodegenerative profile. In parallel, they showed audiogenic generalized clonic seizures. Results from genetic mapping identified the mutation tremor on chromosome 14, in an interval of 5 cM between D14Mit37 (33.21 cM) and D14Mit115 (38.21 cM), making Early Growth Response 3 (Egr3) the main candidate gene. Comparing with wild type (WT) mice, the tremor mice showed higher hippocampal gene expression of Egr3 and Gabra1 and increased concentrations of noradrenalin (NOR; p = .0012), serotonin (5HT; p = .0083), 5-hydroxyindoleacetic acid (5-HIAA; p = .0032), γ-amino butyric acid (GABA; p = .0123), glutamate (p = .0217) and aspartate (p = .0124). In opposition, the content of glycine (p = .0168) and the vanillylmandelic acid (VMA)/NOR ratio (p = .032) were decreased. Regarding to dopaminergic system, neither dopamine (DA) and 3,4-dihydroxyphenylacetic acid (DOPAC) contents nor the turnover rate of DA showed statistically significant differences between WT and mutant mice. Data demonstrated that audiogenic seizures of tremor mice are associated with progressive motor impairment as well as to hippocampal alterations of the Egr3 and Gabra1 gene expression and amino acid and monoamine content. In addition, the tremor mice could be useful for study of neurotransmission pathways as modulators of epilepsy and the pathogenesis of epilepsies occurring with generalized clonic seizures.

Reduced astrocytic expression of GFAP in the offspring of female rats that received hypercaloric diet.

Introduction: Obesity promotes hypothalamic inflammation and local morphological changes in astrocytes, including the increased expression of the astrocytic biomarker glial fibrillary acidic protein (GFAP), which is seen as a sign of neuroinflammation.Objective: This study aimed to observe the astrocytic expression of GFAP in different brain areas from female rats that received a hypercaloric (HD) or a normocaloric (ND) diet during puberty (F0 generation) as well as in their male pups (F1 generation).Methods: Female rats received highly palatable HD (Ensure®) or ND from postnatal day (PND) 23-65. On PND90-95, some were euthanized for the immunohistochemical study and some were mated to obtain the F1 generation. Male pups were immunochallenged on PND50 with lipopolysaccharide (LPS, 100 µg/kg) or 0.9% saline solution (1 mL/kg) intraperitoneal injection. Body weight (BW) and retroperitoneal fat weight (RFW) were recorded on PND95 for F0 generation and on PND50 for F1 generation. GFAP expression for both generations was assessed by morphometry in the parietal/frontal cortex, corpus callosum, nucleus accumbens, arcuate/periventricular nuclei of hypothalamus, pons, molecular/granular layers of cerebellum.Results: Female rats fed with HD presented a significant increase in the GFAP expression in all evaluated areas as well as in the RFW. Male rats born from mothers that received HD showed decreased GFAP expression, BW and RFW when treated with LPS in relation to those from mothers fed with ND.Discussion: HD induced astrogliosis in several brain areas in females from F0 generation and an adaptive phenotypic change of decreased GFAP expression in males from F1 generation after LPS challenge.

Stress resilience evidenced by grooming behaviour and dopamine levels in male mice selected for high and low immobility using the tail suspension test.

Grooming behaviour has different functions on many species during development and can be observed and affected during periods of stress. By selecting male mice with high (HI) and low (LI) immobility traits in the tail suspension test, a screening for antidepressant drugs, we investigate how these phenotypes associated with grooming behaviour may be influenced by the effects of repeated restraint stress. For this we used the sucrose preference test and the splash test in a novel and a familiar cage performed before and after exposure to 2 days of restraint stress. Animals were submitted to an additional day of restraint stress before the hypothalamus, prefrontal cortex and midbrain extraction for dopamine activity analysis. Corticosterone analysis was made in three distinct moments: without stress (prior first restraint session), immediately after the last restrain, and 1 hr after the last restrain episode. Compared to LI group, HI animals exhibited an increased frequency and decreased time of grooming in the familiar cage. In the novel cage, stress increased frequency and time of grooming of HI animals compared to LI. Corticosterone levels were increased in HI animals after 3 days of stress. Lower hypothalamic dopaminergic activity without stress and decreased hypothalamic dopaminergic activity immediately after stress in HI group were observed. The HI group displayed decreased prefrontal cortex dopaminergic activity and increased activity in the mesolimbic area. We proposed that through the influence of stress the two phenotypes manifested as a resilient (LI) and a not resilient (HI) trait in response to restraint stress.

Hyperprolactinemia Impaired the Effects of Lipopolysaccharide on Both Body Temperature and Sickness Behavior in Virgin Female Rats.

OBJECTIVE: Previously we observed an attenuation of body temperature in lactating rats treated with lipopolysaccharide (LPS) compared with virgin saline-treated females. We proposed that high levels of prolactin (PRL) during lactation may induce this attenuation because PRL has a suppressive effect on inflammation. In the present study, we induced hyperprolactinemia in female virgin rats to investigate the effects of PRL on body temperature and sickness behavior induced by LPS. METHODS: To induce hyperprolactinemia, female rats in the estrous phase received domperidone 3 times/day for 5 days and an LPS injection (D + LPS group). Two other groups were treated with saline solution for 5 days, and one of them received a saline injection (S + S group) and the other LPS (S + LPS group). Tympanic temperature was assessed 0, 2, 4, 6, 8, 10, 24, 48, 72, and 96 h after treatment. Body weight gain and food and water consumption were observed 24, 48, 72, and 96 h after treatment. RESULTS: Hyperprolactinemia impaired LPS-induced hypothermia and hyperthermia phases of body temperature. Body weight gains in the S + LPS group and the D + LPS group were similar. A decrease in food consumption was observed in the D + LPS rats at 72 and 96 h compared to the S + LPS group. CONCLUSION: Hyperprolactinemia impaired the body temperature increase induced by LPS and several signs of sickness behavior, suggesting that febrile responses to LPS can be modulated by the physiological state. These phenomena may have adaptive value for reproduction.

Effects of isoflavones on behavior, estradiol, glutamate, and GABA levels in intact middle-aged female rats.

Objectives: Estrogen and phytoestrogens, mainly isoflavones (SIF) treatment has been suggested to improve mood, behavior, and cognitive function in postmenopausal women. However, there is a lack of information on the mechanism of such treatment on the central nervous system. We used rats to investigate the effects of long-term treatment with commercial isoflavones on behavior, hormones, and brain neurotransmitter levels. Methods: Intact female middle-aged (12 months) rats received 50, 100, and 200 mg/kg/day of commercial isoflavones extract by gavage for 90 days. After treatment, locomotor activity, anxiety-like behavior, spatial memory, estradiol, and neurotransmitter levels were measured. Results: Isoflavones treatment decreased total body weight gain in rats received 100 (P < 0.05) and 200 mg/kg (P < 0.05). There were no differences in locomotor activity or anxiety-like behavior; however, isoflavone treatment improved spatial memory (P < 0.05). Estradiol concentration was increased (P < 0.05) in groups SIF 100 and SIF 200. Glutamate (P < 0.01) and γ-aminobutyric acid (GABA) were increased in the prefrontal cortex (PFC) of rats receiving the highest doses and in the hypothalamus in rats that received SIF200 (P < 0.05). Discussion: These findings showed that long-term treatment with commercial isoflavones decreased total body weight gain and facilitated spatial memory performance in rats and this may be involved with the increase in estradiol levels as well as the increase in GABA and glutamate levels in PFC. Furthermore, isoflavones treatment may attenuate age-related cognitive impairment and may therefore be an effective tool to combat this undesirable feature of the natural aging process.

Zinc Alleviates Lipopolysaccharide Interference with Both Body Temperature and Sickness Behavior in Virgin Female Rats.

OBJECTIVES: Previous studies from our group showed that lipopolysaccharide (LPS) exposure induces several signs of sickness behavior, including a decrease in food consumption, body weight gain, adipsia, and a biphasic effect in tympanic temperature with a first phase of hypothermia, followed by an increased tympanic temperature. LPS can activate a chain of nonspecific host responses, including the immune response, and decreased zinc levels. In addition, there are differences in the immune response between males and females, particularly fever, with sex hormones interfering with body temperature. This study aims to characterize the effects of zinc treatment on tympanic temperature, body weight gain, food and water consumption, and general activity in open field of virgin female rats exposed to a dose of LPS that was previously reported to induce sickness behavior. METHODS: Virgin female Wistar rats were treated with either saline (S) or LPS. One hour later, the S group received another injection of saline (S + S group), half of the LPS group received saline (LPS + S group) and the other half received zinc (LPS + Zn group). Tympanic temperature, body weight, and water and food consumption were measured for 96 h. Measurements and observations started 2 h after LPS administration. RESULTS: Treatment with zinc attenuated LPS-increased temperature, decreased the body weight gain and food consumption, and water consumption was increased. CONCLUSION: Zinc treatment is beneficial as it reduces the increased tympanic temperature induced by LPS, but it does not influence other sickness behavior caused by exposure to LPS.

Acute Lipopolysaccharide Switches the Selection of Maternal Behavior to Predatory Behavior in Female Rats.

OBJECTIVES: A common problem during the postpartum period and during lactation is being affected by infection due to Gram-negative bacteria. In this situation, a sick mother needs to choose between caring for her pups or the need for survival. This study analyzed the effects of lipopolysaccharide (LPS)-induced sickness behavior on selection between maternal behavior (MB) and predatory behavior (PB) in lactating rats. To assess the LPS-induced sickness behavior, the plasma tumor necrosis factor-α (TNF-α) levels were measured. METHODS: Lactating rats received 100 µg/kg LPS or saline solution on day 5 or 6 of lactation, 2 h before testing. Five pups and 5 cockroaches were introduced to the experimental cage at the same time and maternal and PB were observed for 30 min. The MB was measured by the pup contact, grouping, grooming, and kyphosis and the PB by contacting, eating, and foraging insects. General maternal activity was also observed, including exploration, self-grooming, and immobility. Immediately after the observations, blood was collected to measure the plasma TNF-α levels. RESULTS: LPS administration reduced the time and frequency of pup contact, grouping, grooming, and kyphosis, with an increase in the latency to first pup contact and grouping. With regard to PB, the time of foraging and eating insects increased, and the latencies to first insect contact, eating insects, and foraging decreased. With regard to general maternal activity, immobility time and TNF-α levels increased in the LPS-treated group. CONCLUSIONS: LPS exposure switched MB to PB, prioritizing maternal survival. Thus, in more favorable situations, these rats may have new offspring and therefore her species would survive for long.

Lipopolysaccharide-induced sickness behavior in lactating rats decreases ultrasonic vocalizations and exacerbates immune system activity in male offspring.

OBJECTIVE: The present study analyzed the effects of lipopolysaccharide (LPS) on maternal behavior during lactation and possible correlations with changes in emotional and immune responses in offspring. METHODS: Lactating rats received 100 µg/kg LPS, and the control group received saline solution on lactation day (LD) 3. Maternal general activity and maternal behavior were observed on LD5 (i.e. the day that the peak of fever occurred). In male pups, hematological parameters and ultrasonic vocalizations (USVs) were assessed on LD5. At weaning, an additional dose of LPS (50 µg/kg, i.p.) was administered in male pups, and open-field behavior, oxidative burst and phagocytosis were evaluated. RESULTS: A reduction in the time in which dams retrieved the pups was observed, whereas no effects on maternal aggressive behavior were found. On LD5, a reduction of the frequency of USVs was observed in pups, but no signs of inflammation were found. At weaning, an increase in immune system activity was observed, but no differences in open-field behavior were found. CONCLUSION: These results indicate that inflammation in lactating mothers disrupted mother/pup interactions and may have produced short- and long-term effects on pup behavior as well as biological pathways that modulate inflammatory responses to bacterial endotoxin challenge in pups.

Effects of chronic mild stress induced from peripuberty on sexual behavior in male rats, with or without escitalopram treatment.

BACKGROUND: After the Coronavirus Disease pandemic, depression became more present, including in adolescents. Escitalopram, a selective serotonin reuptake inhibitor, was approved in 2009 for treatment of the major depressive disorder, both in children and adolescents. The undesirable effects of antidepressants on sexual dysfunction are usually underestimated. AIMS: To investigate the effects of chronic mild stress, induced from peripuberty up to adulthood, on male sexual behavior parameters, with or without the escitalopram treatment, using rats as experimental model in a translational study. MATERIALS AND METHODS: Forty-four peripubertal male rats were distributed into four groups: Sham control, escitalopram, stress, and stress + escitalopram. The chronic mild stress consisted of nine different stressors randomly applied one per day, for 8 weeks (from 41 to 97 days postpartum). Escitalopram therapy by gavage (10 mg/kg) started at 70 days postpartum and lasted for 4 weeks. The male sexual behavior parameters were evaluated at 114 days postpartum. After that, euthanasia was performed for blood and testis collection. Histopathology of the testes and plasmatic testosterone level were carried out. RESULTS: There was a reduction in sexual activity and motivation in rats exposed to the stress protocol, which were treated or not with escitalopram, as well as an increase in the total number of mounts in animals exposed to the stress and treated with escitalopram. The testosterone levels were lower in animals exposed to the stress, which were or not treated with escitalopram (stress and stress + escitalopram). The frequency of histologically normal seminiferous tubule sections was lower in animals that were exposed to the stress and/or received escitalopram (escitalopram, stress, and stress + escitalopram). CONCLUSION: Chronic mild stress induced from peripuberty, associated or not to escitalopram treatment, altered the testosterone levels and testicular histoarchitecture and seems to be related to the reduction in male sexual motivation.

Prenatal restraint stress downregulates the hypothalamic kisspeptidergic system transcripts genes, reduces the estrogen plasma levels, delayed the onset of puberty, and reduced the sexual behavior intensity in female rats.

AIMS: This study investigated the possible relationships between the expression of the Kiss1 and Gpr54 gene expressions and the pituitary-gonadal hormones with the female onset of puberty and sexual behavior. The Kiss1 and Gpr54 gene expressions were examined because they are critical to controlling the hypothalamic activation of GnRH neurons and, in turn, the pituitary-gonadal hormones related to the early onset of puberty and sexual behavior. Further, it was evaluated that the pituitary and gonadal hormones involved in the vaginal opening and the expression of sexual behavior. METHODS: Pregnant rats exposed to PRS from gestation days 17 to 20 were evaluated for maternal and open-field behaviors. The maternal behavior was analyzed because it may alter brain sexual organization affecting the pups development. It was observed in female pups the physical and development and, in adult age, the open-field behavior, the anxiety-like behavior, the estrous cycle, the sexual behavior, the serum FSH, LH, estrogen, progesterone, and testosterone levels, and the gene expression of kisspeptin protein (Kiss1) and Gpr54 in the hypothalamus. RESULTS: the maternal and open-field behaviors were unaffected. In the F1 generation, PRS reduced weight at weaning, delayed the day of the vaginal opening and reduced the intensity of lordosis, the estrogen levels, and the Kiss1 and Gpr54 gene expression. These effects were attributed to hypothalamic kisspeptidergic system downregulation of transcripts genes and the reduced estrogen levels affected by the PRS.

The dopaminergic D1 receptor modulates the hyperactivity of Bapa mutant mice.

The mutant bate-palmas ("claps"; symbol - bapa) mice induced by the mutagenic chemical ENU present motor incoordination and postural alterations. A previous study showed that bapa mice present increased motor/exploratory behaviors during the prepubertal period due to increased striatal tyrosine hydroxylase expression, suggesting striatal dopaminergic system hyperactivity. This study aimed to evaluate the involvement of striatal dopaminergic receptors in the hyperactivity of bapa mice. Male bapa mice and their wild strain (WT) were used. Spontaneous motor behavior was observed in the open-field test, and stereotypy was evaluated after apomorphine administration. The effects of DR1 and DR2 dopaminergic antagonists (SCH-23,390; sulpiride) and the striatal DR1 and D2 receptor gene expression were evaluated. Relative to WT, bapa mice showed: 1) increased general activity for four days; 2) increased rearing and sniffing behavior and decreased immobility after apomorphine; 3) blockage of rearing behavior after the DR2 antagonist but no effect after DR1 antagonist; 4) blockage of sniffing behavior after the DR1 antagonist in bapa and WT mice but no effect after the DR2 antagonist; 5) increased immobility after the DR1 antagonist but no effect after the DR2 antagonist; 6) increased expression of striatal DR1 receptor gene and reduced the DR2 expression gene after apomorphine administration. Bapa mice showed increased activity in open field behavior. The increased rearing behavior induced by apomorphine of bapa mice resulted from the increased gene expression of the DR1 receptor.

Impact of neuroinflammation on epigenetic transcriptional control of Sonic Hedgehog members in the central nervous system.

Sonic Hedgehog (Shh) signaling plays a critical role during central nervous system (CNS) development, and its dysregulation leads to neurological disorders. Nevertheless, little is known about Shh signaling regulation in the adult brain. Here, we investigated the contribution of DNA methylation on the transcriptional control of Shh signaling pathway members and its basal distribution impact on the brain, as well as its modulation by inflammation. The methylation status of the promoter regions of these members and the transcriptional profile of DNA-modifying enzymes (DNA Methyltransferases - DNMTs and Tet Methylcytosine Dioxygenase - TETs) were investigated in a murine model of neuroinflammation by qPCR. We showed that, in the adult brain, methylation in the CpG promoter regions of the Shh signaling pathway members was critical to determine the endogenous differential transcriptional pattern observed between distinct brain regions. We also found that neuroinflammation differentially modulates gene expression of DNA-modifying enzymes. This study reveals the basal transcriptional profile of DNMTs and TETs enzymes in the CNS and demonstrates the effect of neuroinflammation on the transcriptional control of members of the Shh Signaling pathway in the adult brain.

Glyphosate impairs male offspring reproductive development by disrupting gonadotropin expression.

Sexual differentiation in the brain takes place from late gestation to the early postnatal days. This is dependent on the conversion of circulating testosterone into estradiol by the enzyme aromatase. The glyphosate was shown to alter aromatase activity and decrease serum testosterone concentrations. Thus, the aim of this study was to investigate the effect of gestational maternal glyphosate exposure (50 mg/kg, NOAEL for reproductive toxicity) on the reproductive development of male offspring. Sixty-day-old male rat offspring were evaluated for sexual behavior and partner preference; serum testosterone concentrations, estradiol, FSH and LH; the mRNA and protein content of LH and FSH; sperm production and the morphology of the seminiferous epithelium; and the weight of the testes, epididymis and seminal vesicles. The growth, the weight and age at puberty of the animals were also recorded to evaluate the effect of the treatment. The most important findings were increases in sexual partner preference scores and the latency time to the first mount; testosterone and estradiol serum concentrations; the mRNA expression and protein content in the pituitary gland and the serum concentration of LH; sperm production and reserves; and the height of the germinal epithelium of seminiferous tubules. We also observed an early onset of puberty but no effect on the body growth in these animals. These results suggest that maternal exposure to glyphosate disturbed the masculinization process and promoted behavioral changes and histological and endocrine problems in reproductive parameters. These changes associated with the hypersecretion of androgens increased gonadal activity and sperm production.

Perinatal exposure to glyphosate-based herbicides induced neurodevelopmental behaviors impairments and increased oxidative stress in the prefrontal cortex and hippocampus in offspring.

Glyphosate is the organophosphate pesticide most widely used in the world. Recent studies correlate exposure to glyphosate and the emergence of neurodevelopmental disorders. Therefore, it was objective to propose a rat model of perinatal exposure to glyphosate-based herbicides (GBH) to study associated neurodevelopmental disorders. Behavioral aspects and brain pathways were assessed in the prepubertal phase. For this, maternal treatment occurred throughout the entire gestation period (from GD0) until weaning on postnatal day 22 (PND 22). Control group received oral gavage with 5 mL/kg of saline per day and GBH group received oral gavage with 50 mg/kg of GBH per day (n = 10 per group). Maternal behavior was evaluated in PND 2-6. Offspring were evaluated for quantification of ultrasonic vocalizations (PND 5); homing behavior test (PND 13); and hole board, social play behavior, open field, and object recognition tests (PND 28-32). Prefrontal cortex and hippocampus of the offspring were processed to evaluate oxidative stress. Maternal exposure to GBH impaired early social communication, olfactory discrimination, social play behavior, and the exploration of objects, in addition to increasing repetitive and stereotyped movements. GBH also increased oxidative stress. Therefore, perinatal GBH exposure induced behavioral and oxidative stress impairments in rats associated with neurodevelopmental disorders. The manifestations found in the offspring are in accordance with symptoms of autism spectrum disorder.

Long-term maternal separation differentially alters serum corticosterone levels and blood neutrophil activity in A/J and C57BL/6 mouse offspring.

OBJECTIVES: In this work, we searched for maternal separation effects on serum corticosterone levels and blood neutrophil activity in adult male A/J and C57BL/6 mouse offspring. METHODS: 40 male A/J mice and 40 male C57BL/6 mice were divided within each strain into two groups. Mice in the maternal separation group were separated from their mothers (1 h/day) on postnatal days 0-13. Mice in the control group were left undisturbed. On postnatal day 45, blood was drawn from all mice and used to assess neutrophil activity by flow cytometry and serum corticosterone levels by radioimmunoassay. RESULTS: The results showed that each mouse strain responded differently to maternal separation, but in both cases, serum corticosterone levels were affected. In both strains, adult mice that experienced maternal separation showed lower serum corticosterone levels than control mice. In relation to control mice kept together with their mothers, the levels of serum corticosterone were 72.7 and 36.36% lower in A/J and C57BL/6 mice submitted to maternal separation, respectively. The current findings showed that maternal separation increased neutrophil activity in mice after reaching adulthood. The observed effects, although in the same direction, differed between A/J and C57BL/6 mice. Maternal separation increased both the percentage and intensity of phagocytosis in C57BL/6 mice, but had no effects on A/J mice. Furthermore, maternal separation increased basal and propidium iodide-labeled Staphylococcus aureus-induced oxidative burst in A/J mice but did not affect oxidative burst in C57BL/6 mice. Finally, phorbol myristate acetate-induced oxidative burst increased in both strains. CONCLUSION: These results indicate that early maternal separation increases innate immunity, most likely by modifying hypothalamus-pituitary-adrenal axis activity. This suggests that maternal separation is a good model for stress which produces long-term neuroimmune changes whatever the animal species and strain used.