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1.
Int. j. morphol ; 38(6): 1623-1630, Dec. 2020. graf
Article in English | LILACS | ID: biblio-1134489

ABSTRACT

SUMMARY: This study aims to investigate the Effects of Titanium dioxide nanoparticles (TiO2 NPs) on the stereological parameters in the dentate gyrus and the morphology of granular hippocampal neurons in adult mice. Adult male mice (n=20, weight average: 45 g) were randomly divided into four groups including: group receiving saline (controls), low-dose (LD) 2.5 mg/kg TiO TiO2 NPs, medium-dose (MD) 5 mg/kg TiO2 NPs and high-dose (HD) 10 mg/kg TiO2 NPs, daily using gavage for 35 days. To estimate the volume of the hippocampus, dentate gyrus, and sub-layers of dentate gyrus the Cavalieri principle was used. The physical dissector was used to determine the numerical density of dentate gyrus granular cells. For analyzing the morphology of dentate gyrus granular cells the qualitative Golgi staining was used. Our data showed that the total volume of the hippocampus, dentate gyrus and its sublayers including molecular, granular and polymorph in TiO2 treated mice decreased significantly compared to the control group. Moreover, the total number and numerical density of dentate gyrus granular sub layer cells showed a significant reduction in all three experimental groups compared to the control group. The granular cells of the dentate gyrus had shorter dendritic length and decreased dendritic branches in the TiO2-treated in comparison with the control mice. These data can justify the disorders related to memory, learning and hippocampus neurons damages due to using of TiO2 NPs.


RESUMEN: En este estudio se analizaron los efectos de las nanopartículas de dióxido de titanio (TiO2 NP) sobre los parámetros estereológicos en el giro dentado y la morfología de las neuronas granulares del hipocampo en ratones adultos. Se dividieron aleatoriamente ratones machos adultos (n = 20, promedio de peso: 45 g) en cuatro grupos: grupo que recibió solución salina (controles), dosis baja (LD) 2,5 mg/kg NP de TiO2, dosis media (MD) 5 mg/kg de NP de TiO2 y dosis altas (HD) de 10 mg/kg de NP de TiO2, por vía utilizando sonda durante 35 días. Para estimar el volumen del hipocampo, el giro dentado y las subcapas del giro dentado se utilizó el principio de Cavalieri. Se utilizó el disector físico para determinar la densidad numérica de las células granulares del giro dentado. Para analizar la morfología de las células granulares del giro dentado se usó la tinción cualitativa de Golgi. Nuestros datos mostraron que el volumen total del hipocampo, el giro dentado y sus subcapas, incluyendo la molecular, granular y polimorfos, en ratones tratados con TiO2, disminuyó significativamente en comparación con el grupo de control. Además, el número total y la densidad numérica de las células de la subcapa granular del giro dentado mostró una reducción significativa en los tres grupos experimentales en comparación con el grupo control. Las células granulares del giro dentado tenían una longitud dendrítica menor y ramas dendríticas disminuidas en los ratones tratados con TiO2 en comparación con los ratones del grupo control. Estos datos pueden justificar los trastornos relacionados con la memoria, el aprendizaje y los daños en las neuronas del hipocampo debido al uso de NP de TiO2.


Subject(s)
Animals , Male , Mice , Titanium/pharmacology , Dentate Gyrus/drug effects , Nanoparticles , Hippocampus/drug effects
2.
Int. j. morphol ; 38(6): 1693-1699, Dec. 2020. tab, graf
Article in English | LILACS | ID: biblio-1134500

ABSTRACT

SUMMARY: Herbal extracts used for treatment of diabetes has focused mostly on the hypoglycaemic and anti-oxidant property.There are no studies which focused on its effect on dendritic architecture of pyramidal neurons of hippocampus caused by diabetes. This study was taken up to explore the effect of administration of Trigonella foenum-graecum (fenugreek) seed extract on diabetes induced dendritic atrophy in hippocampus. Experimental diabetes was induced in rats by administering single dose of Streptozotocin (60 mg/kg)intraperitoneally.Treatment groups of rats were orally administeredfenugreek seed extract of 1 g/kg body weight for 6 weeks. Followingly they were sacrificed and the brains were removed, processed for the Golgi-Cox stain method.The number of dendritic branching points and intersections were counted in successive radial segments of 20 µm up to a radial distance of 100 micron from soma and analysed by the Sholl's method. The rats with diabetes showed a significant decrease in the dendritic length and branching points in most of the apical and basal dendrites of CA1 and CA3 pyramidal neurons.Treatment with fenugreek seed extract were able to significantly alleviate the dendritic atrophy in most of the segments except in the apical branching points of the CA1 neuron. The present study demonstrates that fenugreek seed extract having a proven hypoglycaemic and anti-diabetic property also possess protection to the hippocampal pyramidal neurons form diabetes associated neuronal atrophy.


RESUMEN: Los extractos de hierbas para el tratamiento de la diabetes se han basado principalmente en las propiedades hipoglucémicas y antioxidantes. En la literatura no hay estudios basados en su efecto sobre la arquitectura dendrítica de las neuronas piramidales del hipocampo, causadas por la diabetes. El objetivo de este estudio fue investigar el efecto de la administración de extracto de semilla de Trigonella foenum graecum (fenogreco) sobre la atrofia dendrítica inducida por la diabetes en el hipocampo. Se indujo diabetes experimental en ratas mediante la administración de una dosis única de estreptozotocina (60 mg / kg) por vía intraperitoneal. Se administró a grupos de ratas extracto de semilla de fenogreco a razón de 1 g / kg de peso corporal durante 6 semanas. Las ratas fueron sacrificadas posteriormente y se procesaron los cerebros mediante método de tinción de Golgi-Cox. El número de puntos de ramificación dendrítica e intersecciones se contaron en segmentos radiales sucesivos de 20 µm hasta una distancia radial de 100 micras del soma y se analizaron mediante el método de Sholl. Las ratas con diabetes mostraron una disminución significativa en la longitud dendrítica y los puntos de ramificación en la mayoría de las dendritas apicales y basales de las neuronas piramidales CA1 y CA3. El tratamiento con extracto de semilla de fenogreco alivió significativamente la atrofia dendrítica en la mayoría de los casos, excepto en los puntos de ramificación apical de la neurona CA1. El estudio demuestra que el extracto de semilla de fenogreco además de tener propiedades hipoglucémicas y antidiabéticas, también protege las neuronas piramidales del hipocampo contra la atrofia neuronal asociada a la diabetes.


Subject(s)
Animals , Male , Rats , Atrophy/drug therapy , Plant Extracts/administration & dosage , Trigonella/chemistry , Dendrites/drug effects , Diabetes Mellitus, Experimental/drug therapy , Plant Extracts/therapeutic use , Rats, Wistar , Pyramidal Cells , Diabetes Mellitus, Experimental/complications , Hippocampus/drug effects
3.
Braz. arch. biol. technol ; 63: e20190113, 2020. graf
Article in English | LILACS | ID: biblio-1132164

ABSTRACT

Abstract Norepinephrine in the basolateral amygdala (BLA) plays a pivotal role in mediating the effects of stress on memory functions in the hippocampus, however, the functional contribution of β1-adrenergic receptors on the BLA inputs to the CA1 region of hippocampus and memory function are not well understood. In the present study the role of β1-adrenoreceptor in the BLA on memory, neuronal arborization and long-term potentiation (LTP) in the CA1 region of hippocampus was examined by infusion the β1-adrenoreceptor agonist (Dobutamine; 0.5µl/side) or antagonist (Atenolol; 0.25µL/side) bilaterally into the BLA before foot-shock stress. Passive avoidance test results showed that Step-through latency time was significantly decreased in the stress group rats one, four and seven days after the stress, which intra-BLA injection of Atenolol or Dobutamine before stress couldn't attenuate this reduction. Barnes-maze results revealed that infusion of Dobutamine and Atenolol significantly reduced spatial memory indicators such as increased latency time, the number of errors and the distance traveling to achieve the target hole in the stress group. These learning impairments in stress rats correlated with a reduction of LTP in hippocampal CA1 synapses in-vivo, which infusion of Dobutamine and Atenolol couldn't attenuate the population spike amplitude and mean-field excitatory postsynaptic potentials (fEPSP) slope reduction induced by stress. Also, the Golgi-Cox staining demonstrated that infusion of Atenolol attenuated stress decreased CA1 region dendritic and axonal arborization. These results suggest that β1-adrenergic receptors activation or block seem to exacerbate stress-induced hippocampal memory deficits and this effect is independent of CA1 LTP modulation.


Subject(s)
Animals , Male , Rats , Stress, Physiological/drug effects , Norepinephrine/metabolism , Dobutamine/pharmacology , CA1 Region, Hippocampal/drug effects , Adrenergic beta-1 Receptor Agonists/pharmacology , Basolateral Nuclear Complex/drug effects , Neuronal Plasticity/drug effects , Rats, Inbred BB , Hippocampus/drug effects
4.
Int. j. morphol ; 37(2): 576-583, June 2019. graf
Article in English | LILACS | ID: biblio-1002261

ABSTRACT

Antidepressants use during pregnancy was associated with an increased risk of autism spectrum disorders. Animal models based on early life alterations in serotonin availability replicate some of the anatomical and behavioral abnormalities observed in autistic individuals. In recent years there has been a growing interest in the possible role of the hippocampus in autism. The aim of study is to examine the effects of neonatal antidepressant (CTM) exposure during a sensitive period of brain development on pyramidal and granule cells density of hippocampal formation. We examined the pyramidal and granular cells density of dorsal hippocampus using Nissl stained sections obtained from neonatal citalopram (CTM) exposed rats (5 mg/kg, twice daily, s.c.), from postnatal day 8 to 21 (PN8-21), saline and non-exposed rats. The density of pyramidal cells was significantly increased by 10.2 % in CA1, 10.6 % in CA3 and 13.2 % in CA4 in CTM treated compared with non-treated or saline treated animals (p<0.0001). The density of granule cells in the dentate gyrus was significantly increased by 12.0 % in CTM treated compared with non-treated or saline treated animals (p<0.0001). These findings were obtained only from male rats, suggesting a sexual dimorphism in neural development after SSRI exposure. These data suggest that the neonatal exposure to CTM may induce long-lasting changes in the hippcampal formation in adults, and such effects appear to preferentially target males.


El uso de antidepresivos durante el embarazo se asoció con un mayor riesgo de trastornos del espectro autista. Los modelos animales basados en alteraciones tempranas de la vida en la disponibilidad de serotonina replican algunas de las anomalías anatómicas y de comportamiento observadas en individuos autistas. En los últimos años ha habido un interés creciente en el posible papel del hipocampo en el autismo. El objetivo del estudio fue examinar los efectos de la exposición al antidepresivo neonatal (CTM) durante un período sensible del desarrollo cerebral en la densidad de las células piramidales y granulares de la formación del hipocampo. Examinamos la densidad de las células piramidales y granulares del hipocampo dorsal utilizando secciones teñidas con Nissl obtenidas de ratas expuestas al citalopram neonatal (CTM) (5 mg / kg, dos veces al día, sc), desde el día postnatal 8 a 21 (PN8-21), solución salina y ratas no expuestas. La densidad de células piramidales se incrementó significativamente en un 10,2 % en CA1, 10,6 % en CA3 y 13,2 % en CA4 en CTM tratados en comparación con animales no tratados o tratados con solución salina (p <0,0001). La densidad de células granulares en el giro dentado aumentó significativamente en un 12,0 % en los animales tratados con CTM en comparación con los animales no tratados o tratados con solución salina (p <0,0001). Estos hallazgos se obtuvieron solo en ratas macho, lo que sugiere un dimorfismo sexual en el desarrollo neural después de la exposición a ISRS. Estos datos sugieren que la exposición neonatal a la CTM puede inducir cambios de larga duración en la formación del hipocampo en adultos, y estos efectos parecen dirigirse preferentemente a los machos.


Subject(s)
Animals , Male , Female , Pregnancy , Rats , Prenatal Exposure Delayed Effects , Citalopram/pharmacology , Hippocampus/drug effects , Antidepressive Agents/pharmacology , Autistic Disorder/chemically induced , Behavior, Animal/drug effects , Citalopram/adverse effects , Cell Count , Sex Factors , Rats, Sprague-Dawley , Pyramidal Cells/drug effects , Hippocampus/cytology , Hippocampus/growth & development , Animals, Newborn , Antidepressive Agents/adverse effects
5.
Rev. bras. anestesiol ; 69(1): 58-63, Jan.-Feb. 2019. graf
Article in English | LILACS | ID: biblio-977426

ABSTRACT

Abstract Background and objectives: Developing brain is more vulnerable to environmental risk than is the developed brain. We evaluated the effects of repeated exposure to different concentrations of sevoflurane on the neonatal mouse hippocampus using stereological methods. Methods: Eighteen neonatal male mice were randomly divided into three groups. Group A, inhaled sevoflurane at a concentration of 1.5%; Group B, inhaled sevoflurane at a concentration of 3%; and Group C (control group), inhaled only 100% oxygen. Treatments were applied for 30 min a day for 7 consecutive days. The hippocampal volume, dendrite length, number of neurons, and number of glial cells were evaluated in each group using stereological estimations. Results: We identified a ∼2% reduction in the volume of the hippocampus in Group A compared to Group C. Mean hippocampal volume was ∼11% smaller in Group B than it was in Group C. However, these differences in hippocampal volume between the groups were not statistically significant (p > 0.05 for all). As for the number of neurons, we found significantly fewer neurons in Group A (∼29% less) and Group B (∼43% less) than we did in Group C (p < 0.05 for both). The dendrite length was ∼8% shorter in Group A and ∼11% shorter in Group B than it was in Group C. Conclusions: Repeated exposure to sevoflurane, regardless of the concentration, reduced the volume of the neonatal mouse hippocampus, as well as the number of neurons and dendrite length.


Resumo Justificativa e objetivos: O cérebro em desenvolvimento é mais vulnerável ao risco ambiental do que o cérebro já desenvolvido. Avaliamos os efeitos da exposição repetida a diferentes concentrações de sevoflurano sobre o hipocampo de ratos neonatos com o uso de métodos estereológicos. Métodos: Dezoito ratos neonatos foram divididos aleatoriamente em três grupos. O Grupo A foi submetido à inalação de sevoflurano a uma concentração de 1,5%; o Grupo B foi submetido à inalação de sevoflurano a uma concentração de 3%; o Grupo C (controle) foi submetido à inalação de apenas oxigênio a 100%. Os tratamentos foram aplicados durante 30 minutos por dia, durante sete dias consecutivos. Volume do hipocampo, comprimento do dendrito, número de neurônios e número de células gliais foram avaliados em cada grupo com o uso de estimativas estereológicas. Resultados: Identificamos uma redução de ∼2% no volume do hipocampo no Grupo A em comparação com o Grupo C. O volume médio do hipocampo foi ∼11% menor no Grupo B do que no Grupo C. Entretanto, essas diferenças no volume do hipocampo entre os grupos não foram estatisticamente significativas (p > 0,05 para todos). Quanto ao número de neurônios, encontramos um número significativamente menor de neurônios no Grupo A (∼29% menos) e no Grupo B (∼43% menos) do que no Grupo C (p < 0,05 para ambos). O comprimento do dendrito foi ∼8% menor no Grupo A e ∼1% menor no Grupo B que no Grupo C. Conclusões: A exposição repetida ao sevoflurano, independentemente da concentração, reduziu o volume do hipocampo neonatal de camundongos, bem como o número de neurônios e o comprimento dos dendritos.


Subject(s)
Animals , Male , Anesthetics, Inhalation/administration & dosage , Sevoflurane/administration & dosage , Hippocampus/drug effects , Random Allocation , Dose-Response Relationship, Drug , Animals, Newborn , Mice
6.
Int. j. morphol ; 37(1): 265-272, 2019. graf
Article in English | LILACS | ID: biblio-990037

ABSTRACT

SUMMARY: Currently many people with epilepsy do not have seizure control even with the best available medications. Moreover various antiepileptics have adverse cognitive impact with other side effect. Thus, need for new antiepileptic drugs still remains challenge. However, many of the natural components have antiepileptic action and this fact remains scientifically unexplored. This study was designed to check the behavioral and neuro-pathological outcome of 1-Triacontanol cerotate (1TAC), isolated from Marsilea quadrifolia Linn. (MQ) on chronic Pentylenetetrazol (PTZ) kindling model of epilepsy in rats. Two-month-old adult male Wistar rats (n=60) were randomly divided into six groups; Group I (Cage Control), II (Vehicle Control), III (Positive Control), IV (Standard drug treated), V (1TAC: 40 mg/kg) & VI (1TAC: 80 mg/kg). To induce kindling a 35 mg/kg dose of PTZ was injected i.p. in every 48 hrs for 30 days in Group III to VI. Spatial memory performance was tested using Morris water maze, following which brains were further processed for histopathological investigations. Interestingly, 1TAC was able to minimize the loss of pyramidal cells in hippocampal CA3 region. These cellular changes were behaviorally responded as improved special learning and memory, a better spatial navigation and object place configuration. The current study strongly implicates that 1TAC from MQ has potent neuroprotective role and augments special memory deficit in chronic epileptic rats. The isolated component which attenuates spatial memory performance could be beneficial outcome to retain cognitive blunting in chronic epilepsy.


RESUMEN: Actualmente, muchas personas con epilepsia no cuentan con un control adecuado de las convulsiones, incluso con los mejores medicamentos disponibles. Además, varios antiepilépticos tienen un impacto cognitivo adverso además de efectos secundarios. Por lo tanto, la necesidad de nuevos fármacos antiepilépticos sigue siendo un desafío. Sin embargo, muchos de los componentes naturales tienen acción antiepiléptica y este hecho permanece científicamente inexplorado. Este estudio se diseñó para verificar el resultado conductual y neuro-patológico del cerotato de 1-triacontanol (1TAC), aislado de Marsilea quadrifolia Linn. (MQ) en el modelo de epilepsia en ratas del pentilenetetrazol (PTZ) crónico (PTZ). Ratas Wistar adultas de dos meses de edad (n = 60) se dividieron aleatoriamente en seis grupos; Grupo I (Control de jaula), II (Control de vehículo), III (Control positivo), IV (Medicamento estándar de tratamiento), V (1TAC: 40 mg / kg) y VI (1TAC: 80 mg / kg). Para inducir la inflamación se inyectó una dosis de 35 mg / kg de PTZ i.p. en cada 48 horas durante 30 días en los grupos III a VI. El rendimiento de la memoria espacial se probó utilizando el laberinto de agua de Morris, después de lo cual se procesaron los cerebros para investigaciones histopatológicas. Curiosamente, 1TAC pudo minimizar la pérdida de células piramidales en la región CA3 del hipocampo. Estos cambios celulares respondieron de manera conductual como una mejora del aprendizaje especial y la memoria, una mejor navegación espacial y la configuración del lugar del objeto. El estudio actual implica fuertemente que 1TAC de MQ tiene un potente papel neuroprotector y mejora el déficit de memoria especial en ratas epilépticas crónicas. El componente aislado que atenúa el rendimiento de la memoria espacial podría ser un resultado beneficioso para retener la reducción cognitiva en la epilepsia crónica.


Subject(s)
Animals , Male , Rats , Marsileaceae/chemistry , Epilepsy/drug therapy , Fatty Alcohols/administration & dosage , CA3 Region, Hippocampal/drug effects , Spatial Memory/drug effects , Pentylenetetrazole/adverse effects , Chronic Disease , Rats, Wistar , Pyramidal Cells , Epilepsy/chemically induced , Fatty Acids , Fatty Alcohols/isolation & purification , Morris Water Maze Test , Hippocampus/drug effects
7.
Acta cir. bras ; 34(12): e201901205, 2019. graf
Article in English | LILACS | ID: biblio-1054687

ABSTRACT

Abstract Purpose To investigate the effects of huperzine A (HupA) on hippocampal inflammatory response and neurotrophic factors in aged rats after anesthesia. Methods Thirty-six Sprague Dawley rats (20-22 months old) were randomly divided into control, isofluran, and isoflurane+HupA groups; 12 rats in each group. The isoflurane+HupA group was intraperitoneally injected with 0.2 mg/kg of HupA. After 30 min, isoflurane inhalation anesthesia was performed in the isoflurane and isoflurane+HupA groups. After 24 h from anesthesia, Morris water maze experiment and open-field test were performed. Hippocampal inflammatory and neurotrophic factors were determined. Results Compared with isoflurane group, in isofluran+HupA group the escape latency of rats was significantly decreased (P < 0.05), the original platform quadrant residence time and traversing times were significantly increased (P < 0.05), the central area residence time was significantly increased (P < 0.05), the hippocampal tumor necrosis factor α, interleukin 6 and interleukin 1β levels were significantly decreased (P < 0.05), and the hippocampal nerve growth factor, brain derived neurotrophic factor and neurotrophin-3 levels were significantly increased (P < 0.05). Conclusion HupA may alleviate the cognitive impairment in rats after isoflurane anesthesia by decreasing inflammatory factors and increasing hippocampal neurotrophic factors in hippocampus tissue.


Subject(s)
Humans , Animals , Male , Sesquiterpenes/pharmacology , Neuroprotective Agents/pharmacology , Anesthetics, Inhalation/adverse effects , Alkaloids/pharmacology , Hippocampus/drug effects , Nerve Growth Factors/drug effects , Enzyme-Linked Immunosorbent Assay , Random Allocation , Reproducibility of Results , Interleukin-6/analysis , Rats, Sprague-Dawley , Maze Learning , Interleukin-1beta/analysis , Hippocampus/metabolism , Isoflurane/adverse effects , Anesthesia/adverse effects , Nerve Growth Factors/analysis
8.
Rev. bras. psiquiatr ; 40(4): 367-375, Oct.-Dec. 2018. graf
Article in English | LILACS | ID: biblio-959251

ABSTRACT

Objective: To evaluate the effects of Hypericum perforatum (hypericum) on cognitive behavior and neurotrophic factor levels in the brain of male and female rats. Methods: Male and female Wistar rats were treated with hypericum or water during 28 days by gavage. The animals were then subjected to the open-field test, novel object recognition and step-down inhibitory avoidance test. Nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and glial cell-line derived neurotrophic factor (GDNF) levels were evaluated in the hippocampus and frontal cortex. Results: Hypericum impaired the acquisition of short- and long-term aversive memory in male rats, evaluated in the inhibitory avoidance test. Female rats had no immediate memory acquisition and decreased short-term memory acquisition in the inhibitory avoidance test. Hypericum also decreased the recognition index of male rats in the object recognition test. Female rats did not recognize the new object in either the short-term or the long-term memory tasks. Hypericum decreased BDNF in the hippocampus of male and female rats. Hypericum also decreased NGF in the hippocampus of female rats. Conclusions: The long-term administration of hypericum appears to cause significant cognitive impairment in rats, possibly through a reduction in the levels of neurotrophic factors. This effect was more expressive in females than in males.


Subject(s)
Animals , Male , Female , Plant Extracts/pharmacology , Cognition/drug effects , Hypericum , Frontal Lobe/metabolism , Hippocampus/metabolism , Nerve Growth Factors/analysis , Plant Extracts/administration & dosage , Random Allocation , Sex Factors , Treatment Outcome , Rats, Wistar , Models, Animal , Pattern Recognition, Physiological/drug effects , Dose-Response Relationship, Drug , Frontal Lobe/drug effects , Hippocampus/drug effects , Locomotion/drug effects , Memory/drug effects , Nerve Growth Factors/drug effects
9.
Arq. neuropsiquiatr ; 76(9): 603-608, Sept. 2018. graf
Article in English | LILACS | ID: biblio-973951

ABSTRACT

ABSTRACT The neuropeptide orexin-A and its receptors are widely distributed in both hippocampal circuitry and pain transmission pathways. Objective: Involvement of the CA1 orexin 1 receptor (OX1R) on the modulation of orofacial pain and pain-induced changes in hippocampal expression of cyclooxygenase-2 (COX-2) and brain-derived neurotrophic factor (BDNF) was investigated. Methods: Orofacial pain was induced by an intra-lip injection of capsaicin (100 μg). Reverse transcription polymerase chain reaction and immunoblot analysis were used to indicate changes in hippocampal BDNF and COX-2 expression, respectively. Results: Capsaicin induces a significant pain response, which is not affected by either orexin-A or SB-334867-A, an OX1R antagonist. However, an increased expression of COX-2 and decreased expression of BDNF was observed in the hippocampus of animals that received capsaicin or SB-334867-A (80 nM) plus capsaicin. Meanwhile, orexin-A (40 pM) attenuated the effects of capsaicin on the expression of COX-2 and BDNF. Conclusions: CA1 OX1R activation moderates capsaicin-induced neuronal inflammation and neurotrophic deficiency.


RESUMO O neuropeptídeo orexina-A e seus receptores estão amplamente distribuídos nos circuitos do hipocampo e nas vias de transmissão da dor. Objetivo: O envolvimento do receptor de orexina 1 CA1 (OX1R) na modulação da dor orofacial e alterações induzidas pela dor na expressão do hipocampo de ciclooxigenase-2 (COX-2) e fator neurotrófico derivado do cérebro (BDNF) foi investigado. Métodos: A dor orofacial foi induzida por injeção intra-labial de capsaicina (100 μg). A reação em cadeia da polimerase de transcrição reversa e a análise de imunotransferência foram utilizadas para indicar alterações na expressão de BDNF e COX-2 no hipocampo, respectivamente. Resultados: A capsaicina induz uma resposta significativa à dor, que não é afetada pela orexina-A ou pelo SB-334867-A, um antagonista do OX1R. No entanto, uma expressão aumentada de COX-2 e uma expressão diminuída de BDNF foi observada no hipocampo de animais que receberam capsaicina ou SB-334867-A (80 nM) mais capsaicina. Enquanto isso, a orexina A (40 pM) atenuou os efeitos da capsaicina na expressão de COX-2 e BDNF. Conclusões: A ativação de CA1 OX1R modera a inflamação neuronal induzida por capsaicina e a deficiência neurotrófica.


Subject(s)
Animals , Male , Rats , Facial Pain/metabolism , Brain-Derived Neurotrophic Factor/metabolism , Cyclooxygenase 2/metabolism , Orexin Receptors/metabolism , Orexins/pharmacology , Hippocampus/metabolism , Urea/analogs & derivatives , Urea/pharmacology , Benzoxazoles/pharmacology , Capsaicin , Rats, Wistar , Reverse Transcriptase Polymerase Chain Reaction , Disease Models, Animal , Hippocampus/drug effects , Naphthyridines , Neurons/drug effects , Neurons/metabolism
10.
Arq. neuropsiquiatr ; 76(1): 32-40, Jan. 2018. graf
Article in English | LILACS | ID: biblio-888340

ABSTRACT

ABSTRACT In this study, the effect of thymoquinone (TQ) on propylthiouracil (PTU)-induced memory impairment was investigated in juvenile rats. The rats were grouped into control, Hypo, Hypo-TQ5 and Hypo-TQ10. Propylthiouracil increased latency time in the Morris water maze test and decreased delay in entering the dark compartment in the passive avoidance test. Both 5 mg/kg and 10 mg/kg doses of TQ decreased latency time in the Morris water maze test and increased delay in entering the dark compartment in a passive avoidance test. The PTU also increased malondialdehyde and nitric oxide metabolites in the brain while reduced the thiol content and superoxide dismutase and catalase activities and serum T4 level. Both doses of TQ decreased malondialdehyde and nitric oxide metabolites in the brain while enhanced the thiol content and superoxide dismutase and catalase activities and serum T4 level. The results of the present study showed that TQ protected against PTU-induced memory impairments in rats.


RESUMO Neste estudo, foi investigado o efeito da timoquinona (TQ) contra deficiências de memória induzidas por propiltiouracilo (PTU) em ratos juvenis. Os ratos foram agrupados em grupos: controle, Hypo, Hypo-TQ5, e Hypo-TQ10. O PTU aumentou o tempo de latência no teste do labirinto aquático de Morris (MWM) e diminuiu o atraso para entrar no compartimento escuro no teste de evasão passiva (PA). Ambas as doses de TQ diminuíram o tempo de latência no teste de MWM e aumentaram o atraso para entrar no compartimento escuro no teste de PA. O PTU também aumentou os metabolitos de malondialdeído (MDA) e óxido nítrico (NO) no cérebro, enquanto reduziu o teor de tiol e as atividades de superóxido dismutasa (SOD) e catalasa (CAT) e o nível sérico de T4. Ambas as doses de TQ diminuíram os metabolitos de MDA e de NO no cérebro, aumentaram o conteúdo de tiol e as atividades de SOD e CAT e o nível de T4 no soro. Os resultados do presente estudo mostraram que a TQ protegeu contra deficiências de memória induzidas por PTU em ratos.


Subject(s)
Animals , Male , Benzoquinones/pharmacology , Oxidative Stress/drug effects , Hypothyroidism/complications , Learning Disabilities/drug therapy , Memory Disorders/drug therapy , Antioxidants/pharmacology , Propylthiouracil , Avoidance Learning/drug effects , Superoxide Dismutase/analysis , Antithyroid Agents , Brain Injuries/metabolism , Catalase/analysis , Rats, Wistar , Maze Learning/drug effects , Disease Models, Animal , Hippocampus/drug effects , Hypothyroidism/chemically induced , Learning Disabilities/chemically induced , Malondialdehyde/analysis , Memory Disorders/chemically induced , Nitric Oxide/analysis
11.
An. acad. bras. ciênc ; 89(4): 2657-2662, Oct.-Dec. 2017. tab
Article in English | LILACS | ID: biblio-886836

ABSTRACT

ABSTRACT The purpose of this study was to determine the effects of the high consumption of sucrose on the levels of DNA damage in blood, hippocampus and bone marrow of rats. Male Wistar rats were treated for 4 months with sucrose (10% for 60 initial days and 34% for the following 60 days) in drinking water, and then, glycemia and glycated hemoglobin (A1C) were measured. Levels of DNA damage in blood and hippocampus were evaluated by the comet assay. The micronucleus test was used to evaluate chromosomal damages in the bone marrow. The sucrose treatment significantly increased (p<0.01) the serum glucose levels (~20%) and A1C (~60%). The level of primary DNA damage was significantly increased (p<0.05) in hippocampal cells (~60%) but not in peripheral blood leukocytes (p>0.05). Additionally, it was observed a significative increase (p<0.05) in the markers of chromosomal breaks/losses in bone marrow, as indicated by the micronucleus test. This is the first study that evaluated DNA damage induced by high sucrose concentration in the hippocampus and bone marrow of rats. Sucrose-induced DNA damage was observed in both tissues. However, the mechanism of sucrose toxicity on DNA remains unknown.


Subject(s)
Animals , Male , Rats , Bone Marrow/drug effects , DNA Damage , Hippocampus/drug effects , Bone Marrow/pathology , Micronucleus Tests , Rats, Wistar , Dietary Sucrose/adverse effects , Comet Assay , Diabetes Mellitus, Type 2/complications , Disease Models, Animal , Hippocampus/pathology
12.
Arq. neuropsiquiatr ; 75(7): 477-483, July 2017. graf
Article in English | LILACS | ID: biblio-888290

ABSTRACT

ABSTRACT In this study, we proposed that administration of hippocampal growth hormone in ageing animals with growth hormone deficiency can compensate long-term potentiation and synaptic plasticity in nucleus basalis magnocellularis (NBM)-lesioned rats. Aged male Wistar rats were randomly divided into six groups (seven in each) of sham-operated healthy rats (Cont); NBM-lesioned rats (L); NBM-lesioned rats and intrahippocampal injection of growth hormone vehicle (L + Veh); NBM-lesioned and intrahippocampal injection of growth hormone (10, 20 and 40 µg.2 µl-1) (L + GH). In vivo electrophysiological recording techniques were used to characterize maintenance of long-term potentiation at distinct times (1, 2, 3, 24 and 48 hours) after high-frequency stimulation. The population spike was enhanced significantly for about 48 hours following tetanic stimulation in rats treated with a dose-dependent growth hormone compared to the vehicle group (p < 0.05), possibly through neuronal plasticity and neurogenesis in affected areas.


RESUMO Neste estudo, propusemos que a administração de hormônio hipocampal do crescimento em animais envelhecidos com deficiência de hormônio do crescimento pode compensar a potencialização em longo prazo e a plasticidade sináptica em ratos lesados do núcleo basalis magnocellularis (NBM). Ratos machos Wistar foram divididos aleatoriamente em seis grupos (sete ratos em cada grupo) de ratos falso-operados saudáveis (Cont); ratos lesados do NBM (L); ratos lesados do NBM e injeção intrahipocampal de veículo de hormônio do crescimento (L + Veh); ratos lesados do NBM e injeção de hormônio do crescimento (10, 20 e 40 μg.2 μl-1) (L + GH). Técnicas de registro eletrofisiológico in vivo foram utilizadas para caracterizar a manutenção da potencialização em longo prazo em momentos distintos (1, 2, 3, 24 e 48 horas) após estimulação de alta frequência. O pico populacional aumentou significativamente cerca de 48 horas após a estimulação tetânica em ratos tratados com um hormônio do crescimento dose-dependente, em comparação com o grupo veículo (p <0,05), possivelmente através da plasticidade neuronal e da neogênese nas áreas afetadas.


Subject(s)
Animals , Male , Growth Hormone/pharmacology , Basal Nucleus of Meynert/drug effects , Hippocampus/drug effects , Neuronal Plasticity/drug effects , Time Factors , Rats, Wistar , Basal Nucleus of Meynert/physiology , Models, Animal , Hippocampus/physiology , Neuronal Plasticity/physiology
13.
An. acad. bras. ciênc ; 89(2): 1133-1141, Apr.-June 2017. graf
Article in English | LILACS | ID: biblio-886699

ABSTRACT

ABSTRACT Studies have shown that schizophrenic patients seem to have nutritional deficiencies. Ascorbic acid (AA) has an important antioxidant effect and neuromodulatory properties. The aim of this study was to evaluate the effects of AA on locomotor activity and the acetylcholinesterase activity (AChE) in an animal model of schizophrenia (SZ). Rats were supplemented with AA (0.1, 1, or 10 mg/kg), or water for 14 days (gavage). Between the 9th and 15th days, the animals received Ketamine (Ket) (25 mg/kg) or saline (i.p). After the last administration (30 min) rats were subjected to the behavioral test. Brain structures were dissected for biochemical analysis. There was a significant increase in the locomotor activity in Ket treated. AA prevented the hyperlocomotion induced by ket. Ket also showed an increase of AChE activity within the prefrontal cortex and striatum prevented by AA. Our data indicates an effect for AA in preventing alterations induced by Ket in an animal model of SZ, suggesting that it may be an adjuvant approach for the development of new therapeutic strategies within this psychiatric disorder.


Subject(s)
Animals , Male , Acetylcholinesterase/analysis , Acetylcholinesterase/drug effects , Ascorbic Acid/pharmacology , Schizophrenia/enzymology , Locomotion/drug effects , Antioxidants/pharmacology , Acetylcholinesterase/physiology , Schizophrenia/prevention & control , Excitatory Amino Acid Antagonists , Dietary Supplements , Corpus Striatum/drug effects , Corpus Striatum/enzymology , Disease Models, Animal , Hippocampus/drug effects , Hippocampus/enzymology , Ketamine , Locomotion/physiology
14.
An. acad. bras. ciênc ; 89(1): 155-161, Jan,-Mar. 2017. tab, graf
Article in English | LILACS | ID: biblio-886639

ABSTRACT

ABSTRACT Several studies have shown that a high consumption of vegetables and fruits is consistently associated with a low risk of oxidative stress-induced diseases, which includes some degenerative diseases such as amyotrophic lateral sclerosis, Alzheimer and Parkinson. Therefore, the objective of this study is to verify the effects of conventional and organic grape juice in the modulation of the neurotrophic factor (BDNF) and astrocytic markers protein (S100B) in hippocampus and frontal cortex of Wistar rats. In this study, 24 male Wistar rats were divided into three groups. To the first one, it was given organic purple grape juice; to the second, conventional grape juice, while the last one received only saline. After 30 days, all rats were sacrificed and hippocampus and frontal cortex were dissected. The animals that received organic and conventional grape juice showed, in frontal cortex, an elevated BNDF levels in relation to saline group. However, S100B levels did not change. These results showed that grape juices are able to modulate important marker in brain tissue, and could be an important factor to prevent brain diseases.


Subject(s)
Animals , Male , Brain-Derived Neurotrophic Factor/analysis , Vitis/chemistry , S100 Calcium Binding Protein beta Subunit/analysis , Fruit and Vegetable Juices , Frontal Lobe/chemistry , Hippocampus/chemistry , Reference Values , Random Allocation , Reproducibility of Results , Rats, Wistar , Brain-Derived Neurotrophic Factor/drug effects , Food, Organic , S100 Calcium Binding Protein beta Subunit/drug effects , Frontal Lobe/drug effects , Hippocampus/drug effects , Antioxidants/pharmacology
15.
Braz. j. med. biol. res ; 50(10): e6161, 2017. tab, graf
Article in English | LILACS | ID: biblio-888938

ABSTRACT

This study aimed to investigate the antidepressant effect and the mechanism of action of Kai-Xin-San (KXS) in fluoxetine-resistant depressive (FRD) rats. Two hundred male Wistar rats weighing 200±10 g were exposed to chronic and unpredictable mild stresses (CUMS) for 4 weeks and given fluoxetine treatment simultaneously. The rats that did not show significant improvement in behavioral indexes were chosen as the FRD model rats. These rats were randomly divided into four groups: FRD model control; oral fluoxetine and aspirin; oral KXS at a dose of 338 mg·kg-1·day-1; and oral KXS at a dose of 676 mg·kg-1·day-1. Rats continued to be exposed to CUMS and underwent treatment once a day for 3 weeks, then cytokine (COX-2, IFN-γ, IL-1β, IL-2, IL-4, IL-6, IL-10, TGF-β, and TNF-α) levels in the hippocampus and serum, and organ coefficients were measured. Both doses of KXS improved the crossing and rearing frequencies, sucrose-preference index, and body weight in FRD rats. KXS at a dose of 338 mg·kg-1·day-1reduced COX-2, IL-2, IL-6, TNF-α levels, increased IL-10 level in the hippocampus, and reduced IL-2 and TNF-α levels in serum. KXS at a dose of 676 mg·kg-1·day-1reduced TNF-α level in the hippocampus, reduced IL-2 and TNF-α levels in serum, and increased IFN-γ and IL-10 levels in the hippocampus and serum. There were no significant differences in organ-coefficients of the spleen among and between groups. The results suggested that oral administration of KXS in FRD rats was effective in improving behavior disorders by influencing various inflammatory pathways.


Subject(s)
Animals , Male , Rats , Antidepressive Agents/therapeutic use , Cytokines/metabolism , Depression/drug therapy , Drugs, Chinese Herbal/therapeutic use , Hippocampus/metabolism , Cytokines/drug effects , Depression/metabolism , Disease Models, Animal , Drug Resistance , Fluoxetine/adverse effects , Hippocampus/drug effects , Random Allocation , Rats, Wistar , Stress, Psychological/psychology
16.
Arq. neuropsiquiatr ; 74(9): 737-744, Sept. 2016. graf
Article in English | LILACS | ID: lil-796045

ABSTRACT

ABSTRACT Cell physiology is impaired before protein aggregation and this may be more relevant than inclusions themselves for neurodegeneration. The present study aimed to characterize an animal model to enable the analysis of the cell biology before and after protein aggregation. Ten-month-old Lewis rats were exposed either to 1 or 2 mg/kg/day of rotenone, delivered subcutaneously through mini-pumps, for one month. Hyperphosphorylated TAU, alpha-synuclein, amyloid-beta peptide and protein carbonylation (indicative of oxidative stress) were evaluated in the hippocampus, substantia nigra and locus coeruleus through immunohistochemistry or western blot. It was found that 2 mg/kg/day rotenone increased amyloid-beta peptide, hyperphosphorylation of TAU and alpha-synuclein. Rotenone at 1mg/kg/day did not alter protein levels. Protein carbonylation remained unchanged. This study demonstrated that aged Lewis rats exposed to a low dose of rotenone is a useful model to study cellular processes before protein aggregation, while the higher dose makes a good model to study the effects of protein inclusions.


RESUMO A fisiologia celular está prejudicada antes da agregação proteica podendo ser mais importante para a neurodegeneração do que as próprias inclusões. Assim, o objetivo deste estudo é caracterizar um modelo animal para analisar os mecanismos e efeitos da agregação proteica. Ratos Lewis com 10 meses de idade foram expostos a rotenona (1 ou 2 mg/kg/dia), administrada subcutaneamente, utilizando minibombas osmóticas. Os níveis de peptídeo beta-amiloide, TAU hiperfosforilada, alfa-sinucleína e proteínas carboniladas (indicativo de estresse oxidativo) foram avaliados por imunohistoquímica e western blot no hipocampo, substância negra e locus coeruleus. Foi demonstrado que 2 mg/kg/dia de rotenona promoveu aumento do peptídeo beta-amiloide, hiperfosforilação da TAU e alfa-sinucleína. Já 1 mg/kg/dia de rotenona não alterou os níveis dessas proteína nessas regiões. As proteínas carboniladas não se alteraram. Foi demonstrado que ratos Lewis idosos expostos a baixas doses de rotenona são modelo de estudo dos processos celulares antes da agregação proteica, enquanto 2 mg/kg/dia de rotenona permite estudos sobre os efeitos da agregação proteica.


Subject(s)
Animals , Male , Rotenone/administration & dosage , Central Nervous System/drug effects , Central Nervous System/pathology , Disease Models, Animal , Protein Aggregation, Pathological/chemically induced , Protein Aggregation, Pathological/pathology , Rats, Inbred Lew , Substantia Nigra/drug effects , Immunohistochemistry , Central Nervous System/metabolism , Blotting, Western , Reproducibility of Results , Amyloid beta-Peptides/drug effects , Amyloid beta-Peptides/metabolism , Oxidative Stress , alpha-Synuclein/drug effects , alpha-Synuclein/metabolism , Alzheimer Disease/metabolism , Alzheimer Disease/pathology , Hippocampus/drug effects , Hippocampus/metabolism , Hippocampus/pathology
17.
An. Fac. Med. (Perú) ; 77(4): 339-344, 2016. ilus, tab
Article in Spanish | MTYCI, LILACS, MTYCI | ID: biblio-1007464

ABSTRACT

Objetivo: Evaluar el efecto de la ingestión de Banisteriopsis caapi y Psychotria viridis 'Binomio ayahuasca' en el hipocampo de cerebro de ratas. Diseño: Estudio experimental, descriptivo, analítico, transversal. Institución: Instituto de Investigación en Ciencias Farmacéuticas y Recursos Naturales, Facultad de Farmacia y Bioquímica, Universidad Nacional Mayor de San Marcos, Lima, Perú. Material biológico: Ratas. Intervenciones: Administración del binomio ayahuasca por vía orogástrica a ratas albinas adultas de la especie Rattus novergicus y de cepa Holtzman. A siete grupos de cinco con un peso promedio de 240 ± 30 g se les administró (GI) blanco, (GII) 2,5 mL diazepam, (GIII) 0,7 mL solución de Banisteriopsis caapi, (GIV) 0,7 mL Psychotria viridis, y a los grupos (GV), (GVI) y (GVII) se administró 0,7 mL, 3,5 mL y 7,0 mL de solución del binomio ayahuasca, respectivamente. Principales medidas de resultados: Macroscópicos: comportamiento de reflejos y actividad motora. Microscópicos: número de células piramidales y granulosas, y desorganización celular. Resultados: En el tamizaje fitoquímico del extracto se caracterizó presencia de alcaloides, antraquinonas, triterpenoides y esteroides, fenoles, flavonoides y saponinas. Los volúmenes de droga administradas a los grupos de intervención con el binomio en la dosis de 0,7 mL manifestaron significativo aumento en el número de células granulosas sobre las células piramidales; a dosis de 3,5 mL el número de células granulosas fue menor con presencia de células piramidales grandes y pequeñas; y a dosis de 7,0 mL se manifestó desorganización celular, presencia de células piramidales grandes y pequeñas, y aumento de células granulosas. Conclusiones: El extracto alcohólico del binomio ayahuasca presenta efecto neuropatológico en el hipocampo del cerebro de ratas. (AU)


Subject(s)
Animals , Rats , Banisteriopsis , Psychotria , Hippocampus/drug effects , Peru , Plants, Medicinal , Models, Animal , Medicine, Traditional
18.
Article in English | WPRIM | ID: wpr-110770

ABSTRACT

In this study, we investigated the effects of chronic aluminum (Al) exposure for 10 weeks on cell proliferation and neuroblast differentiation in the hippocampus of type 2 diabetic rats. Six-week-old Zucker diabetic fatty (ZDF) and Zucker lean control (ZLC) rats were selected and randomly divided into Al- and non-Al-groups. Al was administered via drinking water for 10 weeks, after which the animals were sacrificed at 16 weeks of age. ZDF rats in both Al- and non-Al-groups showed increases in body weight and blood glucose levels compared to ZLC rats. Al exposure did not significantly affect body weight, blood glucose levels or pancreatic β-cells and morphology of the pancreas in either ZLC or ZDF rats. However, exposure to Al reduced cell proliferation and neuroblast differentiation in both ZLC and ZDF rats. Exposure to Al resulted in poor development of the dendritic processes of neuroblasts in both ZLC and ZDF rats. Furthermore, onset and continuation of diabetes reduced cell proliferation and neuroblast differentiation, and Al exposure amplified reduction of these parameters. These results suggest that Al exposure via drinking water aggravates the impairment in hippocampal neurogenesis that is typically observed in type 2 diabetic animals.


Subject(s)
Aluminum/toxicity , Animals , Blood Glucose/analysis , Cell Differentiation/drug effects , Cell Proliferation/drug effects , Diabetes Mellitus, Experimental/pathology , Diabetes Mellitus, Type 2/pathology , Disease Models, Animal , Hippocampus/drug effects , Neurogenesis/drug effects , Random Allocation , Rats, Zucker
19.
Trends psychiatry psychother. (Impr.) ; 37(3): 143-151, jul. set. 2015. tab, graf
Article in English | LILACS | ID: lil-764667

ABSTRACT

Objective:To investigate the effects of ethanol exposure in adolescent rats during adulthood by assesssing aggression and anxiety-like behaviors and measuring the levels of inflammatory markers.Methods:Groups of male Wistar rats (mean weight 81.4 g, n = 36) were housed in groups of four until postnatal day (PND) 60. From PNDs 30 to 46, rats received one of three treatments: 3 g/kg of ethanol (15% w/v, orally, n = 16), 1.5 g/kg of ethanol (12.5% w/v, PO, n = 12), or water (n = 12) every 48 hours. Animals were assessed for aggressive behavior (resident x intruder test) and anxiety-like behaviors (elevated plus maze) during adulthood.Results:Animals that received low doses of alcohol showed reduced levels of brain-derived neurotrophic factor (BDNF) in the hippocampus as compared to the control group. No significant difference was found in prefrontal cortex.Conclusions:Intermittent exposure to alcohol during adolescence is associated with lower levels of BDNF in the hippocampus, probably due the episodic administration of alcohol, but alcohol use did not alter the level agression toward a male intruder or anxiety-like behaviors during the adult phase.


Objetivo: Investigar os efeitos da exposição ao etanol em ratos adolescentes durante a idade adulta sobre os comportamentos agressivos e semelhantes à ansiedade, bem como sobre as medidas de níveis de marcadores inflamatórios.Métodos:Os grupos de ratos Wistar machos (peso médio de 81,4 g; n = 36) foram alojados em grupos de quatro até o dia pós-natal (DPN) 60. Entre os DPNs 30 e 46, os ratos receberam um dos três tratamentos: 3 g/kg de etanol (15% w/v, oralmente, n = 16), 1.5 g/kg de etanol (12,5% w/v, oralmente, n = 12), ou água (n = 12) a cada 48 horas. Os comportamentos agressivos (teste residente-intruso) e semelhantes à ansiedade (labirinto em cruz elevado) foram avaliados durante a idade adulta dos animais.Resultados:Os animais que receberam doses menores de álcool mostraram níveis reduzidos de fator neurotrófico derivado do cérebro (BDNF) no hipocampo quando comparados ao grupo controle. Nenhuma diferença significativa foi verificada no córtex pré-frontal.Conclusões:A exposição intermitente ao álcool durante a adolescência é associada com menores níveis de BDNF no hipocampo, provavelmente divido a administração episódica de álcool, mas o uso não alterou o nível de agressão contra o macho intruso ou os comportamentos semelhantes à ansiedade durante a fase adulta.


Subject(s)
Animals , Male , Central Nervous System Depressants/administration & dosage , Ethanol/administration & dosage , Binge Drinking/metabolism , Binge Drinking/psychology , Hippocampus/growth & development , Hippocampus/drug effects , Anxiety/physiopathology , Risk-Taking , Central Nervous System Depressants/adverse effects , Tumor Necrosis Factor-alpha/metabolism , Interleukin-10/metabolism , Rats, Wistar , Prefrontal Cortex/growth & development , Prefrontal Cortex/drug effects , Prefrontal Cortex/metabolism , Brain-Derived Neurotrophic Factor/metabolism , Aggression/drug effects , Aggression/physiology , Aggression/psychology , Disease Models, Animal , Ethanol/adverse effects , Dose-Response Relationship, Drug , Interleukin-1alpha/metabolism , Hippocampus/metabolism
20.
Int. j. morphol ; 33(3): 962-970, Sept. 2015. ilus
Article in English | LILACS | ID: lil-762571

ABSTRACT

Hypoxia-ischemia (HI) is a major cause of brain damage in the newborn. Several studies elicited the neuroprotective effects of progesterone in adult rats but there is very little literature available on neonatal rats. Therefore the present study is undertaken to see the effect of progesterone in hypoxic ischemic brain injury in neonatal rats, using an established neonatal HI rat pup model. Seven-day-old rat pups were subjected to right common carotid artery ligation and then 60 minutes hypoxia. The first dose of progesterone to treatment group was administered by peritoneal injection (4 mg/kg), after 10 minutes of exposure and subsequent doses were given by subcutaneous injection at 6 h, 24 h and 48 h intervals. Control group was also exposed to HI and was given only the vehicle (peanut oil) through the same route and intervals as that of treatment group. After 96 h, the pups were perfused with 10% formalin and brains were sampled and stained with toluidine blue. Cells density and number of pyramidal cells of the hippocampal Cornu Ammonis (CA) regions were examined by stereological methods. The histomorphometric assessment of the effects of progesterone showed minimal but no significant protective value in the volume, cells density and total number of pyramidal cells of hippocampal CA region of the treatment and control groups (p>0.05) after HI. Our results concluded that 4 mg/kg of PROG had no significant neuroprotective effect in HI model of the neonatal rat's hippocampus.


La hipoxia-isquémica (HI) es una causa importante de daño cerebral en el recién nacido. Varios estudios indican los efectos neuroprotectores de la progesterona en ratas adultas, sin embargo existe poca literatura disponible en ratas recién nacidas. Por tanto, el presente estudio se llevó a cabo para ver el efecto de la progesterona en la lesión cerebral HI en ratas recién nacidas, utilizando un modelo de cría de rata neonata HI establecido. A los siete días de nacidas, las crías de ratas fueron sometidas a la ligadura de la arteria carótida común derecha y luego 60 minutos de hipoxia. La primera dosis de progesterona fue administrada al grupo de tratamiento mediante inyección peritoneal (4 mg/kg), después de 10 minutos de exposición y las dosis posteriores fueron administradas por inyecciones subcutáneas en intervalos de 6 h, 24 h y 48 h. El grupo control también fue expuesto a HI y se le administró solamente aceite de cacahuete a través de la misma ruta y con los intervalos que recibió el grupo de tratamiento. Después de 96 h, las crias fueron perfundidas con formalina al 10% y se tomaron muestras de los cerebros, los que se tiñeron con azul de toluidina. La densidad celular y el número de células piramidales de las regiones del hipocampo Cornu Ammonis (CA) fueron examinadas por métodos estereológicos. La evaluación histomorfométrica de los efectos de la progesterona mostró un valor protector mínimo, pero no significativo en el volumen, densidad de las células y el número total de células piramidales de la región de CA del hipocampo de los grupos de tratamiento y control (p>0,05) después de HI. En conclusión, nuestros resultados indican que 4 mg/kg de progesterona no tuvo efecto neuroprotector significativo en el modelo de HI del hipocampo de ratas neonatas.


Subject(s)
Animals , Male , Rats , Hippocampus/drug effects , Hypoxia-Ischemia, Brain/pathology , Progesterone/pharmacology , Animals, Newborn , Hippocampus/cytology , Hippocampus/pathology , Neuroprotective Agents , Pyramidal Cells/drug effects , Pyramidal Cells/pathology , Rats, Sprague-Dawley
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