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.

Acute and subacute (28 days) toxicity of green coffee oil enriched with diterpenes cafestol and kahweol in rats.

Green coffee oil enriched with cafestol and kahweol was obtained by supercritical fluid extraction using carbon dioxide while its safety and possible effects from acute and subacute treatment were evaluated in rats. For acute toxicity study, single dose of green coffee oil (2000 mg/kg) was administered by gavage in female rats. For subacute study (28 days), 32 male rats received different doses of green coffee oil extract (25, 50, and 75 mg/kg/day). In the acute toxicity study, main findings of this treatment indicated no mortality, body weight decrease, no changes in hematological and biochemical parameters, and relative weight increase in heart and thymus, without histopathological alterations in all assessed organs. All these findings suggest that LD50 is higher than aforesaid dose. In the subacute toxicity, main findings showed body weight decrease mainly at the highest dose without food consumption change, serum glucose and tryglicerides levels decrease, and relative weight increase in liver. As evidenced in histopathological pictures, no changes were observed at all treated doses. Our study suggest that green coffee oil can be explored to clinically develop new hypocholesteromic and hypoglycemic agents. However, further studies evaluating long-term effects are needed in order to have sufficient safety evidence for its use in humans.

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.

Maternal Immune Activation with the Viral Mimetic Poly:IC in Pregnant Rats.

Maternal immune activation (MIA) is increasingly well appreciated as an environmental risk factor for some psychiatric disorders. Administration of proinflammatory compounds such as the synthetic double-stranded RNA molecule polyinosinic-polycytidylic acid (polyI:C) to pregnant rodents results in the release of proinflammatory cytokines in the maternal circulation. Various behavioural and brain changes are produced in the offspring that are associated with psychiatric disorders such as autism and schizophrenia. This protocol describes the steps necessary for inducing MIA in pregnant rat dams, which will allow for investigations into the mechanisms in the dam and offspring that mediate the long-term effects of exposure to inflammation while in utero. Increasing our understanding of these mechanisms may provide new insights for the diagnosis, treatment, and prevention of psychiatric disorders. This protocol has been developed and improved over the years by various researchers in Dr. Howland's laboratory at the University of Saskatchewan.

Behavioral and neurochemical characterization of the mlh mutant mice lacking otoconia.

Otoconia are crucial for the correct processing of positional information and orientation. Mice lacking otoconia cannot sense the direction of the gravity vector and cannot swim properly. This study aims to characterize the behavior of mergulhador (mlh), otoconia-deficient mutant mice. Additionally, the central catecholamine levels were evaluated to investigate possible correlations between behaviors and central neurotransmitters. A sequence of behavioral tests was used to evaluate the parameters related to the general activity, sensory nervous system, psychomotor system, and autonomous nervous system, in addition to measuring the acquisition of spatial and declarative memory, anxiety-like behavior, motor coordination, and swimming behavior of the mlh mutant mice. As well, the neurotransmitter levels in the cerebellum, striatum, frontal cortex, and hippocampus were measured. Relative to BALB/c mice, the mutant mlh mice showed 1) reduced locomotor and rearing behavior, increased auricular and touch reflexes, decreased motor coordination and increased micturition; 2) decreased responses in the T-maze and aversive wooden beam tests; 3) increased time of immobility in the tail suspension test; 4) no effects in the elevated plus maze or object recognition test; 5) an inability to swim; and 6) reduced turnover of dopaminergic system in the cerebellum, striatum, and frontal cortex. Thus, in our mlh mutant mice, otoconia deficiency reduced the motor, sensory and spatial learning behaviors likely by impairing balance. We did not rule out the role of the dopaminergic system in all behavioral deficits of the mlh mutant mice.

Prolonged exposure of rats to varenicline increases anxiety and alters serotonergic system, but has no effect on memory.

Varenicline is a drug used for smoking addiction cessation treatment and acts as a partial agonist of nicotinic cholinergic receptors. Recent clinical trial data support use of varenicline for treatment of conditions/addictions that are not related to smoking cessation. Considering the importance of this issue and the need for new studies on its effects, especially on behavior, more studies using animal models are necessary. Thus, the aim of this study was to evaluate the effects of prolonged exposure to varenicline in anxiety-like behavior and memory, as well as in cerebral neurochemistry of rats. Male rats received three different doses of varenicline: 0.03 (therapeutic dose for humans), 0.1 and 0.3 mg/kg orally (gavage) for 30 days. Animal behavior was analyzed through open field, elevated plus maze, light/dark box, social interaction, Barnes maze and novel object recognition tests. Neurotransmitter levels and their metabolites in different brain structures (hippocampus, striatum and frontal cortex) were measured. Results showed that prolonged exposure of rats to varenicline: 1) did not interfere in motor activity, but caused an anxiogenic effect on elevated plus maze, light/dark box and social interaction testes; 2) did not alter memory; and 3) promoted alterations on serotoninergic system in the striatum and frontal cortex. In conclusion, compilation of the data indicates that prolonged exposure of rats to varenicline promoted anxiogenic effects and alteration in serotonergic system, which corroborated behavioral findings.

Evaluation of Prolonged Exposure to Varenicline in Adult Rats: Haematological, Biochemical and Anatomopathological Studies.

Varenicline is a synthetic chemical substance produced from the alkaloid cytisine, used for smoking treatment, which acts as a partial agonist for α4ß2 and α3ß4 nicotinic cholinergic receptors and as a total agonist for α7 receptor. While there are studies regarding varenicline's non-smoking-related effects, as in treatment for drug dependence, there are no studies in the literature evaluating the long-term toxicity of varenicline through a physiological approach. Thus, the aim of this study was to evaluate possible toxicity through haematological, biochemical and anatomopathological parameters of prolonged exposure (30 days) to varenicline in rats. Three doses of varenicline were used: 0.03 (therapeutic dose for human beings), 0.1 and 0.3 mg/kg orally (gavage). Body-weight, water and food intake were measured weekly during treatment. On the 30th treatment day, blood and various organs were collected for haematological, biochemical and anatomopathological evaluations. The results show a decrease in some biochemical parameters in animals from the 0.1 and 0.3 mg/kg group, although the values are within the normal range of the species. There were no changes in the other evaluations performed. Together, these data indicate that prolonged exposure of rats to different doses of varenicline was not able to alter haematological, biochemical and anatomopathological parameters.

Perinatal exposure to an aromatase inhibitor glyphosate-base herbicide reduced male and female social behavior in juvenile age and the sexual behavior at adult female rats / Exposição perinatal ao inibidor da aromatase a base de glifosato reduz o comportamento social de machos e fêmeas e o comportamento sexual de ratas

Objectives: The herbicide glyphosate, a pesticide used in agriculture to control weeds, both in food crops and in other agricultural areas, has been identified as an endocrine modulator through the inhibition of aromatase activity and the activation of estrogen receptors. The present study examined the effects of a glyphosate-based herbicide (Roundup® (GLY-BH) on sexual dimorphism of rats after perinatal exposure to low and high GLY-BH in males and females offspring. Methods: Two groups of pregnant rats were treated with two doses of GLY-BH (50 or 150 mg/kg) from day 15 of gestation (GD15) to postnatal day 7 (PND7). Play fighting behavior was observed at the juvenile stage and during social and sexual behaviors in adulthood. Results: Perinatal GLY-BH exposure reduced male and female body weight at 28, 75, and 90 days of age. The play fighting behavior was decreased in both sexes, but female rats were more affected. The sexual behaviors were reduced only in females. Conclusions: Perinatal exposure to both doses of GLY-BH promoted sexually dimorphic effects in both juvenile and adulthood stages. These effects were attributed to the inhibition of aromatase activity induced by exposure to GLY-BH in the perinatal period.(AU)

Objetivos: O glifosato é um herbicida não seletivo, usado em muitas culturas alimentares e não alimentares e em áreas não agrícolas, sendo que os produtos a base de glifosato atuam como moduladores das funções endócrinas por meio da inibição da atividade da aromatase e da ativação de receptores de estrógeno. O presente estudo avaliou os efeitos do herbicida Roundup® (GLY-BH) à base de glifosato, em comportamentos sexualmente dimórficos de ratos após exposição perinatal a doses baixas e altas de GLY-BH no período perinatal. Métodos: Ratas prenhas foram tratadas com 50 ou 150 mg/kg de GLY-BH do 15º dia de gestação (GD15) ao 7º dia de lactação (LD7). O comportamento de luta/brincar foi observado na fase juvenil e os comportamentos social e sexual na idade adulta. Resultados: a exposição perinatal a GLY-BH reduziu o peso corporal de machos e fêmeas aos 28, 75 e 90 dias de idade. O comportamento de luta/brincar diminuiu em ambos os sexos, sendo as ratas foram as mais afetadas. O comportamento sexual foi reduzido apenas nas fêmeas. Conclusões: A exposição perinatal a ambas as doses do GLY- BH promoveu tanto na idade juvenil como na idade adulta, efeitos sexualmente dimórficos. Esses efeitos foram atribuídos à inibição da atividade da aromatase induzida exposição perinatal ao GLY-BH.(AU)

Bioimpressão e produção de mini-órgãos com células tronco / Bioprinting with stem cells and production of mini-organs

A bioimpressão é considerada uma fonte promissora no desenvolvimento celular, e na produção de mini-órgãos, válulas, cartilagens que futuramente poderão ser utilizados na terapia para transplantes em animais e humanos. Assim, essa técnica poderá ser utilizada como uma terapia eletiva, no tratamento de injúrias e principalmente no tratamento de doenças crônico-degenerativas. Em humanos essa terapia está sendo pesquisada a fim de auxiliar a medicina no tratamento e regeneração de tecidos impressos a partir de arcabouços de células desenvolvidas a partir de células-tronco, biomateriais e impressões em 3D. O uso dessa tecnologia é também um auxiliar nas pesquisas oncológicas com o intuito de projetar e avaliar a proliferação celular de tumores, bem como a ação de novos medicamentos quimioterápicos. No entanto, a maior limitação para o uso da terapia utilizando-se a impressora de células, órgãos e tecidos em 3D é a falta de protocolos unificados com metodologias reprodutíveis e detalhadas; com o objetivo de viabilizar a utilização da impressora e a impressão de células, órgãos e tecidos em 3D. Dessa forma, esta revisão busca reunir as publicações mais atuais na área, as quais destacam os avanços no uso de bioimpressão com células-tronco, a fim de descrever as principais técnicas e os potenciais de utilização como alternativa terapêutica na medicina humana e veterinária.(AU)

The bioprinting is considered a promising source in cell development, and production of mini-organs, valves, cartilage that may eventually be used in therapy for transplantation in animals and humans. It can also be used as an elective therapy in the treatment of injuries and treatment of chronic degenerative diseases. In humans, this therapy is been studied mainly in the treatment and regeneration of tissues printed from scaffold cells developed from stem cells, biomaterials and impressions in 3D. This technology is also an aid for the study of the formation of tumors, in order to design and evaluate the cellular proliferation of the tumors and the action of new chemotherapy drugs. However, the main drawback to this therapy is the lack of standardized protocols with reproducible and detailed methodologies with the aim of enabling the use of bioprinting and printing cells, tissues and organs in 3D. Thus, this review seeks to bring together the most current publications of the bioprinting area in order to describe the technique and its potential use as a therapeutic alternative.(AU)

Avaliação dos efeitos da exposição prolongada às isoflavonas em ratas na senescência: aspectos comportamentais, bioquímicos e anatomopatológicos / Evaluation of the effects of prolonged isoflavones exposure in rats on senescence: behavioral, biochemical and anatomopathological aspects

O envelhecimento é um processo acompanhado por uma série de mudanças físicas, fisiológicas e psicológicas, além de ser caracterizado pelo declínio de diferentes funções motoras e cognitivas, que afetam a independência do idoso. Particularmente na mulher, um acompanhante inevitável do envelhecimento é a menopausa. Desse modo, é natural o interesse em medidas terapêuticas que possam ser utilizadas para minimizar os sintomas da menopausa, bem como o prejuízo motor e cognitivo. Assim, o presente estudo teve como objetivo (i) avaliar o efeito da idade nos aspectos comportamentais, neuroquímicos e de ácidos graxos poli-insaturados em ratas jovens (3 meses de idade), de meia-idade (12 meses de idade) e senescentes (18 meses de idade); e, (ii) avaliar os efeitos da administração prolongada (90 dias) de diferentes doses (50, 100 e 200 mg/kg/dia) de isoflavonas (ISOs) no perfil comportamental, na análise bioquímica sérica e de estradiol, na quantificação dos níveis de neurotransmissores encefálicos e achados anatomopatológicos em ratas de meia-idade. Os resultados da primeira etapa mostraram que: ratas com 12 e 18 meses de idade apresentaram: 1) diminuição da frequência de levantar e de grooming no campo aberto; 2) aumento do comportamento tipo-ansioso no labirinto em cruz elevado e na caixa claro-escuro; 3) prejuízo na memória espacial observada no labirinto de Barnes; 4) diminuição, sobretudo, nos níveis de dopamina e de seus metabólitos no córtex pré-frontal (CPF), no hipotálamo, no hipocampo e no estriado; 5) diminuição dos níveis dos hidróxidos 12 e 15/14 do ácido araquidônico (AA) no CPF de ratas com 18 meses de idade. Esses dados em conjunto evidenciam prejuízo motor e cognitivo, aumento do comportamento tipo-ansioso, bem como redução nos níveis de monoaminas e dos hidróxidos do AA com o avanço da idade das ratas. Em relação ao tratamento prolongado com diferentes doses de ISOs em ratas de meia-idade, os resultados mostraram que: 1) não houve alterações motoras e no comportamento tipo-ansioso; 2) evidenciou melhora no desempenho cognitivo espacial; 3) mostrou aumento nos níveis séricos de estradiol e 4) promoveu aumento nos níveis de glutamato e de GABA no CPF e no hipotálamo. Esses achados sugerem que o tratamento prolongado com diferentes doses de ISOs em ratas de meia-idade, foi capaz de melhorar a performance cognitiva espacial e esse efeito pode ser associado ao aumento dos níveis de estrógeno, bem como ao aumento dos níveis de glutamato e de GABA no córtex pré-frontal e no hipotálamo, evidenciando também um possível efeito neuroprotetor das ISOs em ambas regiões.

Aging is a process accompanied by a series of physical, physiological and psychological changes, besides being characterized by the decline of different motor and cognitive functions, which affect the independence of the elderly. Specifically, in women, an inevitable companion of aging is menopause. Therefore, it is of high interest therapeutic procedures that can be used to reduce the symptoms of menopause, as well as motor and cognitive impairment. Thus, the present study aimed to (i) evaluate the effect of age on behavioral, neurochemical and polyunsaturated fatty acids aspects in young (3 months old), middle-aged (12 months old) and senescent (18 months of age) female rats; and (ii) to evaluate the effects of prolonged (90 days) administration of different doses (50, 100 and 200 mg/kg/day) of isoflavones (ISOs) in the behavioral profile, biochemical and estradiol serum analysis, brain neurotransmitters levels and anatomopathological findings in middle-aged rats. Our first results showed that rats at 12 and 18 months of age: 1) presented a decrease in rearing and grooming frequency in the open field; 2) increase of anxiety-like behavior in the elevated plus maze and light-dark box; 3) spatial memory impairment observed in the Barnes maze; 4) a decrease mainly in the levels of dopamine and its metabolites in the prefrontal cortex (PFC), hypothalamus, hippocampus and striatum; 5) decreased levels of 12 and 15/14 arachidonic acid (AA) hydroxides in the PFC in 18-month old rats . These data altogether show motor and cognitive impairment, increase in anxiety-like behavior, as well as reductions in monoamine levels and AA hydroxides as the rat age progresses. Regarding the prolonged treatment with different doses of ISOs in middle-aged rats, the results showed that: 1) there were no motor or anxiety-like behavior alterations; 2) there was an improvement in spatial cognitive performance; 3) increase in serum estradiol levels and 4) increase in glutamate and GABA levels in the PFC and hypothalamus. These findings suggest that prolonged treatment with different doses of ISOs could improve spatial cognitive performance and that this effect may be associated with increased estrogen levels, as well as increased levels of glutamate and GABA in the prefrontal cortex and hypothalamus, evidencing a possible neuroprotective effect of ISOs in both regions.