Motor Coordination Disorders Evaluated through the Grid Test and Changes in the Nigral Nrf2 mRNA Expression in Rats with Pedunculopontine Lesion.

Neurotoxic lesion of the pedunculopontine nucleus (PPN) is known to cause subtle motor dysfunctions. However, motor coordination during advance on a discontinuous and elevated surface has not been studied. It is also not known whether there are changes in the mRNA expression of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) in nigral tissue. METHODS: The effects of the unilateral neurotoxic lesion of the PPN in motor coordination evaluated through grid test and Nrf2 mRNA expression in nigral tissue were evaluated. Two experimental designs (ED) were organized: ED#1 behavioral study (7 and 30 days after PPN lesion) and ED#2 molecular biology study (24 h, 48 h and 7 days) after PPN lesion. RESULTS: ED#1-The number of faults made with left limbs, were significant higher in the lesioned groups (p < 0.01) both 7 and 30 days post-lesion. The number of failures made by the right limbs, was also significantly higher (p < 0.05) vs. control groups. ED#2-Nrf2 mRNA expression showed an increase 24 h after PPN injury (p < 0.01), followed by a peak of expression 48 h post injury (p < 0.001). CONCLUSIONS: Disorders of motor coordination associated with PPN injury are bilateral. The increased Nrf2 mRNA expression could represent an adaptive response to oxidative stress in the nigral tissue following pontine injury.

Nurr1, Pitx3, and α7 nAChRs mRNA Expression in Nigral Tissue of Rats with Pedunculopontine Neurotoxic Lesion.

Background and Objectives: The knowledge that the cholinergic neurons from pedunculopontine nucleus (PPN) are vulnerable to the degeneration in early stages of the Parkinson disease progression has opened new perspectives to the development of experimental model focused in pontine lesions that could increase the risk of nigral degeneration. In this context it is known that PPN lesioned rats exhibit early changes in the gene expression of proteins responsible for dopaminergic homeostasis. At the same time, it is known that nicotinic cholinergic receptors (nAChRs) mediate the excitatory influence of pontine-nigral projection. However, the effect of PPN injury on the expression of transcription factors that modulate dopaminergic neurotransmission in the adult brain as well as the α7 nAChRs gene expression has not been studied. The main objective of the present work was the study of the effects of the unilateral neurotoxic lesion of PPN in nuclear receptor-related factor 1 (Nurr1), paired-like homeodomain transcription factor 3 (Pitx3), and α7 nAChRs mRNA expression in nigral tissue. Materials and Methods: The molecular biology studies were performed by means of RT-PCR. The following experimental groups were organized: Non-treated rats, N-methyl-D-aspartate (NMDA)-lesioned rats, and Sham operated rats. Experimental subjects were sacrificed 24 h, 48 h and seven days after PPN lesion. Results: Nurr1 mRNA expression, showed a significant increase both 24 h (p < 0.001) and 48 h (p < 0.01) after PPN injury. Pitx3 mRNA expression evidenced a significant increase 24 h (p < 0.001) followed by a significant decrease 48 h and seven days after PPN lesion (p < 0.01). Finally, the α7 nAChRs nigral mRNA expression remained significantly diminished 24 h, 48 h (p < 0.001), and 7 days (p < 0.01) after PPN neurotoxic injury. Conclusion: Taking together these modifications could represent early warning signals and could be the preamble to nigral neurodegeneration events.

Tyrosine Hydroxylase, Vesicular Monoamine Transporter and Dopamine Transporter mRNA Expression in Nigrostriatal Tissue of Rats with Pedunculopontine Neurotoxic Lesion.

BACKGROUND: The degeneration of the pedunculopontine nucleus (PPN) precedes the degeneration of the nigral cells in the pre-symptomatic stages of Parkinson's disease (PD). Although the literature recognizes that a lesion of the PPN increases the vulnerability of dopaminergic cells, it is unknown if this risk is associated with the loss of capability of handling the dopaminergic function. METHODS: In this paper, the effects of a unilateral neurotoxic lesion of the PPN in tyrosine hydroxylase (TH), vesicular monoamine transporter 2 (VMAT2) and dopamine transporter (DAT) mRNA expression in nigrostriatal tissue were evaluated. Three experimental groups were organized: non-treated rats, NMDA-lesioned rats and Sham-operated rats. RESULTS: Seven days after the PPN lesion, in nigral tissue, TH mRNA expression was higher in comparison with control groups (p < 0.05); in contrast, VMAT2 mRNA expression showed a significant decrease (p < 0.01). DAT mRNA expression showed a significant decrease (p < 0.001) in the striatal tissue. Comparing nigral neuronal density of injured and control rats revealed no significant difference seven days post-PPN injury. CONCLUSIONS: Findings suggest that the PPN lesion modifies the mRNA expression of the proteins associated with dopaminergic homeostasis at nigrostriatal level. It could represent vulnerability signals for nigral dopaminergic cells and further increase the risk of degeneration of these cells.

Motor dysfunction and alterations in glutathione concentration, cholinesterase activity, and BDNF expression in substantia nigra pars compacta in rats with pedunculopontine lesion.

Pedunculopontine nucleus (PPN) has been considered a critically important region in the regulation of some of the physiological functions that fail during the progression of Parkinson's disease (PD). In this paper, the effects of unilateral neurotoxic lesion of the PPN [through the injection of N-methyl-d-aspartate (NMDA) solution (concentration: 0.1M; volume: 0.5µL)] in motor execution and gait disorders and the changes in cellular and molecular indicators in rat nigral tissue were evaluated. The motor execution was assessed using the beam test (BT) and the gait disorders by footprint test. Glutathione (GSH) concentrations, acetyl cholinesterase enzymatic activity (AChE EA), and brain-derived neurotrophic factor (BDNF) mRNA expression in nigral tissue were analyzed. NMDA-lesioned rats showed fine motor dysfunction with a significant increase in the slow (p≤0.01) and fast movement (p≤0.01) time and in path deviation (p≤0.01) on the smaller diameter beams. Moreover, NMDA-lesioned rats exhibited an imprecise path with moments of advances and setbacks, alternating with left and right deviations, suspensions, and inverted positions. Footprint test revealed slight gait disorders, which were manifested by a reduction in the left and right stride lengths, the intra-step distance, and the support area (p≤0.01). Biochemical studies showed that 48h after the PPN neurotoxic injury, the GSH concentrations and BDNF expression were significantly increased (p≤0.01). These variables returned to normal values 7days after the PPN lesion; the AChE EA showed a significant increase at this time. These functional changes in nigral tissue could be a plastic responses associated with early PD.

Primera incursión en la obtención de curieles libre de patógenos específicos en Cuba / First foray into the production of specific pathogen-free guinea pigs in Cuba

Resultados confiables y económicos solo son obtenidos cuando los animales de experimentación son aislados de factores ambientales y biológicos, implantándose en el biomodelo una microbiota normal, lejos de la presencia de microorganismos patógenos. El objetivo de la investigación fue obtener curieles libre de patógenos específicos por cesárea aséptica, mantenidos en aisladores y alimentados con dietas estériles. Se realizaron 26 histerectomías. Los animales fueron alimentados con una fórmula modificada (L-477) en forma de papilla hasta los 21 días y permanentemente después la C-484 sólida y granulada, esterilizadas a 121oC/20 minutos o a 1,5Mrad. Además fueron suplementados con vitamina C y B1. El forraje o heno fue consumido a partir de la primera generación. La microbiota gastrointestinal se administró por vía oral en 0,5 ml de una dilución de 10-6/g de contenido de la porción final del íleon, ciego y principio del colon de curieles, a las 24 y 48 horas del nacimiento. Se utilizó para el monitoreo microbiológico caldo Tioglicolato, caldo Triptona Soya y caldo Saboraud incubados aeróbicamente a temperatura de 55, 37 y 25oC respectivamente. Se obtuvieron 51 neonatos. La mortalidad más alta se registró entre los primeros 10 días de edad (58,8%). Se lograron 12 animales (3 machos y 9 hembras), 6 de las hembras se reprodujeron aproximadamente a los 9 meses de edad, lográndose 11 crías por parto normal. La metodología aplicada permitió obtener curieles libres de Salmonella sp, Pasteurella sp, Streptococcus del tipo A y C, Bordetella bronchiseptica, Toxoplasma gondii, Virus Sendai y parásitos internos y externos.

Confidence and economics results are only obtained when the animals are isolated of the environmental and biological factors, that could interfere the course of from investigation and when is being established in them, a normal microflora balanced far from the presence of pathogen microorganisms. They were accomplished 26 histerectomies. The animals were fed with a modified formula of L-477 in the form of porridge until 21 days of age and permanently after with the C-484 solid and granulated, sterilized at 121oC/20 minutes or 1,5Mrad. The forage or hay was consumed by the first generation since the 6 months of age. The gastrointestinal flora was administered by oral route with 0,5 ml of a dilution of 10-6/g of the contents of the ileum final portion, cecum and first part of the colon of conventionalized Dunkin Hartley guinea pigs, at 24 and 48 hours born. It was used for microbiological bacteria monitoring Thioglycolate broth, Tryptic Soy broth and Sabouraud broth incubated aerobically at temperatures of 55, 37 and 25oC respectively. There were obtained 51 newborns. The highest mortality was registered during the first 10 days of age (58,8%). There were archieved 12 animals: 9 female and 3 males. 6 of the female were reproduced approximately at 9 months of age and were archieved 11 normal delivery sucklings. There were obtained guinea pigs free of the followings specific pathogens: Salmonella sp., Pasteurella sp., Streptococcus of the group A y C. Bordetella bronchiseptica, Toxoplasma gondii, Sendai Virus, beside internal and external parasites.

Desarrollo de la formulación Compvit-B® inyectable / Development of Compvit-B® injectable formulation

El incremento de la incidencia de las polineuropatías en Cuba a principio de la década de los 90 del pasado siglo, hizo necesario la aplicación de medicamentos con propiedades antineuríticas, compuestos por vitaminas del grupo B, que hasta el momento no existían en el país por los altos precios a los que se comercializan internacionalmente. Objetivo: obtener una formulación que en su composición contenga una asociación de altas dosis de las vitaminas B1, B6 y B12, cuyos efectos positivos en el tratamiento de las neuropatías ya son conocidos. Métodos: se evaluaron integralmente ocho variantes diferentes de una formulación inyectable, con la presencia o no de etilendiaminotetraacético (EDTA) y alcohol bencílico, y el proceso de liofilización incluido o no en su flujo productivo de acuerdo con la propuesta de la tecnología del fabricante. Resultados: se seleccionó la variante 8, la que cumple con los parámetros establecidos por la tecnología del fabricante y el Centro para el Control Estatal de la Calidad de los Medicamentos (CECMED). Se obtuvo un producto farmacéutico inyectable, liofilizado de factura nacional llamado Compvit-B®, compuesto por 100 mg de B1, 100 mg de B6 y 5 000 µg de B12, que cumple con las especificaciones propuestas y que exigen los órganos regulatorios en la producción de medicamentos para uso humano. Conclusiones: La variante seleccionada permitió desarrollar el producto farmacéutico Compvit-B® que es un medicamento farmacológicamente estable y de calidad, y cuya licencia sanitaria para su generalización y producción fue otorgada por el CECMED...

"At the beginning of the 1990´s, the increased incidence of polyneuropathies in Cuba made it necessary to apply vitamin B group-derived drugs with neuroprotective properties. this kind of drugs was infrequent in the country at that time because of their high prices at the international market. Objectives: to obtain a formulation containing a combination of high dose of vitamins B1, B6 and B12 which have known positive effects on the treatment of neuropathies. Methods: comprehensive assessment of eight different variants of injectable formulation, with or without ethylenediaminetetraacetic acid (EDTA) and benzyl alcohol, and of the lyophilization process included in the flow of production or not, in line with the technology suggested by the manufacturer. Results: the variant number 8 was selected since it meets the set parameters according to the manufacturer's technology and to the Center for the State Quality Control of Drugs. A Cuban-made injectable and lyophilized pharmaceutical called Compvit-B®, made up of 100 mg B1, 100 mg B6 and 5 000 µg B12, was obtained. It meets the established specifications and the requirements by the regulatory bodies for the manufacture of drugs for human use. Conclusions: the selected variant allowed developing the Compvit-B ® pharmaceutical, which is a pharmacologically stable drug of quality, and the health licensing for the general use and the production of this drug was granted by the Center for the State Quality Control of Drugs (CEDMED)...

Actividad antiinflamatoria y antioxidante de Bauhinia kalbreyeri Harms en un modelo de inflamación intestinal agudo en ratas / Anti-inflammatory and antioxidant action of Bauhinia kalbreyeri Harms in an acute intestinal inflammation model used in rats

Objetivo: evaluar la actividad antiinflamatoria y antioxidante de extractos acuosos de hojas y corteza de Bauhinia kalbreyeri Harms mediante un modelo de inflamación intestinal en ratas. Métodos: se utilizaron ratas Wistar, a las cuales se les indujo inflamación intestinal aguda mediante el uso de indometacina (15 mg/kg). Los extractos se administraron por gavage (40 mg/kg) durante 7 d. Se midieron los niveles enzimáticos de glutatión peroxidasa (GPX/L de sangre), se determinó el índice de actividad de la enfermedad y se realizó una caracterización macroscópica y microscópica de las lesiones. Resultados: se determinó que la administración oral de los extractos tiene un efecto moderado sobre el modelo agudo de enteritis inducida por indometacina, con la disminución concomitante de los parámetros clínicos, patológicos e inflamatorios. Tanto el análisis histológico como el macroscópico de las muestras de animales tratados con extractos, confirmaron el efecto beneficioso ejercido por estos en el modelo de enteritis aguda inducida por indometacina, el cual se atribuye a los metabolitos secundarios presentes en la planta ya que se evidenció recuperación de la citoarquitectura, disminución en el grado de lesión y del índice de actividad de la enfermedad; así como la estabilización de los niveles de glutatión peroxidasa, que aumenta la viabilidad de las fibras de colágeno, evita el daño celular y promueve la síntesis de ADN, para iniciar la recuperación de la lesión. Conclusión: este estudio se muestra como uno de los pioneros en dilucidar la actividad antiinflamatoria y antioxidante de Bauhinia kalbreyeri en un modelo in vivo.

Objective: to evaluate the anti-inflammatory and antioxidant activity of aqueous extracts of leaves and bark from Bauhinia kalbreyeri Harms in an intestinal inflammation model applied to Wistar rats. Methods: the Wistar rats were induced acute intestinal inflammation by using indomethacin (15 mg/kg). The extracts were administered by gavage (40 mg/kg) for 7 days. The enzyme levels of glutathione peroxidase (GPX/L of blood) were measured, the rate of disease activity was estimated, and finally the lesions were macroscopically and microscopically characterized. Results: it was found that oral administration of the extracts has a modest effect on acute enteritis model induced by indomethacin, with concomitant decrease in the clinical parameters and inflammatory disease. Both the macroscopic and histological analysis of samples from the animals treated with extracts confirmed their beneficial effect on the indomethacin-induced acute enteritis model. This effect is attributed to the secondary metabolites in the plant since the experiment evidenced recovery of cytoarchitecture, lower degree of injury, reduced rate of disease activity, as well as stabilization of glutathione peroxidase levels that cause more viability of the collagen fibers, prevent cell damage and encourage DNA synthesis to start recovery from injury. Conclusions: this study seems to be one of the pioneers in elucidating the anti-inflammatory and antioxidant properties of Bauhinia kalbreyeri in an in vivo model.

El núcleo pedunuulopontino y su relación con la fisiopatología de la enfermedad de parkinson / The Pedunculopontine Nucleus and its Relationship to the Pathophysiology of Parkinson's Disease

Varias décadas de investigaciones neuropatológicas e imagenológicas han proporcionado suficientes evidencias acerca de las alteraciones en la neurotransmisión colinérgica que acompañan a la disfunción dopaminérgica en la enfermedad de Parkinson (EP). El núcleo pedunculopontino tegmental laterodorsal (NPP) representa una de las fuentes principales de proyecciones colinérgicas en el cerebro y a su vez es el origen de la única proyección colinérgica que recibe la substantia nigra pars compacta (SNpc). Actualmente el estudio de la participación del NPP en la fisiopatología de la EP toma en cuenta dos vertientes: el impacto de la pérdida temprana de la influencia excitatoria pontina sobre la SNpc asociado a la degeneración temprana del NPP y la estimulación a baja frecuencia del NPP como tratamiento quirúrgico beneficioso para los signos axiales de la EP. El NPP ha emergido como una estructura esencial en la comprensión de la fisiopatología de la EP dado sus relaciones con los núcleos de los ganglios basales, el tálamo, la corteza motora y la médula espinal. La degeneración de algunas de sus poblaciones neuronales en etapas presintomáticas de la EP ha sugerido una relación causa-efecto entre este hallazgo y la muerte de las células dopaminérgicas nigrales. Por otra parte la estimulación del NPP tiene resultados favorables sobre los trastornos posturales y de la marcha, los cuales se presentan en etapas tardías de la EP y son refractarios a otros tratamientos farmacológicos y quirúrgicos.

Several decades of neuropathologic and imagenologic investigations have provided sufficient evidences about alterations in cholinergic neurotransmission that go together with the dopaminergic dysfunction in Parkinson s disease (PD). The laterodorsal tegmental pedunculopontine nucleus (PPN) represents one of the main sources of cholinergic projections into the brain and at the same time the origin of the only cholinergic projection that substantia nigra pars compacta (SNpc) receives. At present, the study of the PPN participation as part of the physiopathology of PD has two notions: the impact of the lack of pontine excitatory influence on SNpc, associated to the early degeneration of PPN as well as the low frequency stimulation in the PPN as a beneficial surgical treatment for the axial symptoms of PD. PPN has emerged as an essential structure in the comprehension of PD physiopathology, given by its relation with the basal ganglia nuclei, thalamus, motor cortex and the spinal cord. The degeneration of some of its neuronal populations in PD pre symptomatic steps, has suggested a cause- and-effect relation on this finding and the death of nigral dopaminergic cells. On the other hand, PPN stimulation has favorable results on postural and gait disorders, which present themselves in late PD stages and are refractory to other pharmacological and surgical treatments.

Estabilidad del producto farmacéutico Compvit-BÒ inyectable / Stability of injectable pharmaceutical Compvit-BÒ

Compvit-BÒ es un polifármaco inyectable liofilizado, compuesto por 100 mg de B1, 100 mg de B6 y 5 000 µg de B12. Está indicado en tratamientos de todo tipo de neuropatías y enfermedades neurodegenerativas. El objetivo de este trabajo consistió en el desarrollo tecnológico de una formulación estable. Para evaluar la calidad de este medicamento, se escalaron 3 lotes pilotos a los que se les realizaron ensayos físicos, químicos y microbiológicos con resultados satisfactorios. Los estudios de estabilidad realizados a temperatura ambiente del producto Compvit-BÒ en forma liofilizada, demostraron ser estable por 3 años y la formulación reconstituida por 72 h. Este medicamento está registrado en el órgano regulador cubano, Centro Estatal para el Control de Medicamentos, e incluido en el Cuadro Básico de Medicamentos de Cuba; se comercializa por la Industria Farmacéutica nacional y se encuentra generalizado en los servicios hospitalarios de Cuba

Compvit-BÒ is a lyophilized injectable polypharmaceutical made up of 100 mg of B1, 100 mg of B6 and 5 000 µg of B12. It is prescribed to treat all types of neuropathies and neurodegenerative diseases. The objective of this paper was the technological development of a stable formulation. For the evaluation of the quality of this drug, three pilot batches were scaled up and were subjected to physical, chemical and microbiological tests; the results were all satisfactory. The stability studies of lyophilized Compvit-BÒ were performed at room temperature. They showed that the pharmaceutical was stable for 3 years and the formulation was regenerated for 72 hours. This drug is registered at the Cuban regulating body called State Center for Drug Control and has been included in the Basic Group of Drugs in Cuba. It has been put on the market by the national drug industry. It is also widely used in the hospital services in Cuba

Estabilidad del producto farmacéutico Compvit-BÒ inyectable / Stability of injectable pharmaceutical Compvit-BÒ

Compvit-BÒ es un polifármaco inyectable liofilizado, compuesto por 100 mg de B1, 100 mg de B6 y 5 000 µg de B12. Está indicado en tratamientos de todo tipo de neuropatías y enfermedades neurodegenerativas. El objetivo de este trabajo consistió en el desarrollo tecnológico de una formulación estable. Para evaluar la calidad de este medicamento, se escalaron 3 lotes pilotos a los que se les realizaron ensayos físicos, químicos y microbiológicos con resultados satisfactorios. Los estudios de estabilidad realizados a temperatura ambiente del producto Compvit-BÒ en forma liofilizada, demostraron ser estable por 3 años y la formulación reconstituida por 72 h. Este medicamento está registrado en el órgano regulador cubano, Centro Estatal para el Control de Medicamentos, e incluido en el Cuadro Básico de Medicamentos de Cuba; se comercializa por la Industria Farmacéutica nacional y se encuentra generalizado en los servicios hospitalarios de Cuba(AU)

Compvit-BÒ is a lyophilized injectable polypharmaceutical made up of 100 mg of B1, 100 mg of B6 and 5 000 µg of B12. It is prescribed to treat all types of neuropathies and neurodegenerative diseases. The objective of this paper was the technological development of a stable formulation. For the evaluation of the quality of this drug, three pilot batches were scaled up and were subjected to physical, chemical and microbiological tests; the results were all satisfactory. The stability studies of lyophilized Compvit-BÒ were performed at room temperature. They showed that the pharmaceutical was stable for 3 years and the formulation was regenerated for 72 hours. This drug is registered at the Cuban regulating body called State Center for Drug Control and has been included in the Basic Group of Drugs in Cuba. It has been put on the market by the national drug industry. It is also widely used in the hospital services in Cuba(AU)

Establecimiento de las condiciones para el trasplante de células de médula ósea en un modelo de enfermedad de Huntington y su efecto funcional a través de la conducta motora / Establishment of the conditions for the bone marrow cells transplants in a model of Huntington´s disease and functional effect on the motor behavior

La enfermedad de Huntington (EH) es un trastorno degenerativo hereditario que afecta a personas con predisposición genética. No existe hasta hoy un tratamiento efectivo; la enfermedad avanza lentamente y el paciente termina en incapacidad o muerte después de 15 o 20 años. Los estudios relacionados con el tratamiento de las manifestaciones clínicas que aparecen en la enfermedad, incluyen tratamientos medicamentosos y el uso de trasplante de células. En la actualidad se conoce que es posible reproducir algunas características de la enfermedad en modelos experimentales para ensayar posibles terapéuticas (ej. el modelo de lesión estriatal por inyección de ácido quinolínico; [AQ]). No se conoce el efecto restaurativo de las células de médula ósea (CMO) en este modelo. Objetivos: 1) Caracterizar morfológicamente la lesión por inyección intraestriatal de AQ. 2) Caracterizar inmunocitoquímicamente las CMO. 3) Evaluar la concentración óptima de CMO para el trasplante en el modelo y 4) Evaluar el estado funcional del trasplante de CMO, a través de la conducta motora.

Huntington Disease (HD) is a heritable neurodegenerative disease that affects people with genetic history. Until today, an effective treatment doesn't exist; the illness advances slowly and the patient finishes in inability or death after 15 or 20 years. The studies related with the treatment of the clinical manifestations, include treatments with medications and the use of cells transplant. At the present time it is known that it is possible to reproduce, some characteristics of the disease in experimental models for to use possible therapies [example: estriatal lesion of quinolínico acid; (QA)]. the restorative effect of the bone marrow cells (BMC) is not known in this model. Objectives. 1) characterizationmorphofological of the estriatal lesion whith QA. 2) to characterization immunochemical of BMC. 3) to evaluate the BMC concentration for the transplant and 4) to evaluate the functional state of BMC transplant, through the motor behavior.

Efecto de la adiinistración intracerebral de mk801 y (-) nicotina en las conceentraciones extracelulares de glu y gaba en el núcleo pedunculopontino de ratas / Effect of the Mk801 and (-) Nicotine Intracerebral Administration on Glu and Gaba Extracellular Concentration in the Pedunculopontine Nucleus from Rats

Aunque la manipulación farmacológica de los sistemas glutamatérgico y colinérgico se ha tratado en modelos experimentales de enfermedad de Parkinson (EP), pocos autores han realizado estudios de esta temática a nivel del núcleo pedunculopontino (NPP). El presente trabajo aborda los cambios en las concentraciones extracelulares (CE) de glutamato (Glu) y ácido δ-amino butírico (GABA) en el NPP de ratas hemiparkinsonizadas por inyección de 6-hidroxidopamina (6-OHDA) y sometidas a infusión local de MK-801 (10 µmol/L) o (-) nicotina (10 mM). La infusión se realizó mediante microdiálisis cerebral y la determinación de CE de neurotransmisores se realizó a través de cromatografía líquida de alta resolución acoplada a detección de fluorescencia. La infusión de MK-801 en el NPP produjo disminución significativa de CE de Glu (p< 0,01) y de GABA (p < 0,01) en ratas hemiparkinsonizadas y controles. La infusión de (-) nicotina mostró un incremento significativo de CE de Glu (p < 0,001) y GABA (p< 0,001) en el NPP de ratas hemiparkinsonizadas y controles. El bloqueo local de receptores NMDA por MK-801 facilita la interacción de Glu con sus receptores metabotrópicos que participan en mecanismos de inhibición presináptica y bloquean la liberación de neurotransmisores. Mientras que la infusión de nicotina en el NPP suma los efectos de activación de los receptores nicotínicos a los cambios conocidos en la neurotransmisión glutamatérgica y gabaérgica en el NPP en parkinsonismo. La infusión de fármacos glutamatérgicos y colinérgicos en el NPP, impone un reajuste a la neurotransmisión a este nivel que se añade a los cambios neuroquímicos asociados a denervación dopaminérgica.

Although the pharmacological manipulation of the glutamatergic and cholinergic systems have been studied in animal models of Parkinson´s disease (PD), only some authors have done work on this topic at the pedunculopontine nucleus (PPN). The present work studied the changes in glutamate (Glu) and δ-aminobutyric acid (GABA) extracellular concentrations (EC) in the PPN from hemiparkinsonian rats by 6hydroxydopamine injection. The rats were locally perfused by MK-801 (10 µmol/L) or (-) nicotine (10 mM) solutions by cerebral microdyalisis. The biochemical studies were carried out through high performance liquid chromatography coupled to fluorescence detection. MK-801 infusion induced a significant decrease of Glu (p< 0.01) and GABA (p< 0.01) EC in PPN. On the other hand (-) nicotine infusion induced a significant increase of Glu (p< 0.001) and GABA (p< 0.001) EC in PPN from hemiparkinsonian rats. The local blockade of NMDA receptors by MK-801 infusion facilitates the interaction between Glu and their metabotropic receptors that take part in presynaptic inhibition mechanisms and interfere with neurotransmitters release. Meanwhile, the nicotine infusion sums the effects of nicotinic receptor activation with the glutamatergic and gabaergic neurotransmission changes produced in the PPN in the parkinsonian condition. The cholinergic and glutamergic drug infusion in PPN impose a new adjustment to the neurotransmition at this level that is added to the neurochemical changes associated to dopaminergic denervation.

Enfermedad de hnntington: modelos experimentales y perspectivas terapéuticas / Huntington'disease: Experimentals Models and Therapeutic Perspectives

La enfermedad de Huntington (EH) es un trastorno degenerativo de Weiss de origen hereditario. Hasta el momento no existe un tratamiento efectivo para la enfermedad que inexorablemente después de transcurridos 15 a 20 años, evoluciona hacia incapacidad total o muerte. En este trabajo se revisan las características clínicas y morfológicas de la EH y los modelos experimentales más utilizados para su estudio tomando como fuente, artículos indexados en la base de datos Medline publicados en los últimos 20 años. Se valoran las ventajas y desventajas de estos modelos y su perspectiva para el desarrollo de ensayos clínicos. El consenso de lo reportado plantea que de los modelos tóxicos, los inducidos por neurotoxinas tales como ácido quinolínico parecen ser los más adecuados para reproducir las características neuropatológicas, y por otro lado los modelos genéticos contribuyen con más evidencias al conocimiento del origen etiológico de la enfermedad. Numerosos tratamientos han sido aplicados en el manejo de las manifestaciones clínicas que aparecen en EH, sin poder detener o disminuir las afectaciones que derivan de la pérdida neuronal. La sintomatología clínica ha sido posible reproducirla, al menos en parte, en animales de experimentación lo que ha permitido realizar ensayos terapéuticos. Desde el punto de vista de tratamiento, lo que más promisorio parece ser, la terapia celular con células provenientes de diferentes fuentes y dentro de ellas las no neurales, que implican menor censura ética y mayor factibilidad de obtención para la aplicación en los enfermos. Por otro lado el desarrollo de la tecnología del ARN de interferencia, emerge como una herramienta terapéutica potencial para el tratamiento de EH, así como para responder interrogantes básicas relacionadas con el desarrollo de la enfermedad.

Huntington'disease (HD) is a degenerative dysfunction of hereditary origin. Up to date there is not, an effective treatment to the disease which having lapsed 15 or 20 years advances inexorably, in a slow form, toward the total inability or death. This paper reviews the clinical and morphological characteristics of Huntington's disease as well as the experimental models more commonly used t study this disease, having as source the articles indexed in Medline data base, published in the last 20 years. Advantages and disadvantages of all experimental models to reproduce the disease as well as the perspectives to therapeutic assay have been also considered. The consent of outline reported about the toxic models, those induced by neurotoxins such as quinolinic acid, appears to be the most appropiate to reproduce the neuropathologic characteristic of the disease, an genetic models contributing with more evidence to the knowledge of the disease ethiology. Numerous treatments ameliorate clinical manifestations, but none of them has been able to stop or diminish the affectations derived from neuronal loss. At present time it is possible to reproduce, at least partially, the characteristics of the disease in experimentation animals that allow therapy evaluation in HD. From the treatment view point, the more promissory seems to be transplantation of no neuronal cells, taking into account ethical issues and factibility. On the other hand the new technology of interference RNA, emerges as a potential therapeutic tool for treatment in HD, and to respond basic questions on the development of the disease.

Aplicación del eest de la barra transversal modficado para evaluar ratas hemipparkinsonizadas. / Modify Beam Transversal Test to Evauate Hemiparkinsonian Rats.

La degeneración nigroestriatal que caracteriza a la enfermedad de Parkinson (EP) es estudiada en modelos experimentales en roedores por inyección de 6-hidroxidopamina (6-OHDA). El presente estudio presenta una versión modificada del test de la barra transversal (TBT) que permite la cuantificación del déficit motor a través de: tiempo que demora la rata en alcanzar una de las plataformas (latencia de escape, LE); tiempo que demora en caer de la barra (latencia de caída, LC); número total de errores cometidos durante la ejecución en cada barra (número de errores, NE). La forma y el diámetro de la sección transversal de la barra se modificaron desde barras rectangulares y circulares de 2,5 cm de diámetro hasta barras con esta misma forma y 1 cm de diámetro respectivamente lo cual impuso la mayor dificultad a la ejecución del test. Tres grupos de ratas Wistar fueron evaluados: no tratadas (n=15), lesionadas con 6-OHDA (n=14) y falsas operadas (n=14). Todas las variables estudiadas mostraron diferencias signifi-cativas entre ratas controles y hemiparkinsonizadas. Para todos los tipos de barras, las variables LE y NE se incrementaron mientras que la LC disminuyó significativamente en las ratas hemiparkinsonizadas en comparación con las ratas controles. La LC mostró diferencias altamente significativas (p<0,001) entre las barras de mayor y menor diámetro. TBT es un test que explora la función sensoriomotora, no requiere grandes sesiones de entrenamiento previo ni motivación aversiva ni deprivación de alimento. Este test resulta de gran utilidad para evaluar las deficiencias motoras que se presentan en el modelo de hemiparkinsonismo unilateral así como en otros modelos experimentales de enfermedades neurodegenerativas.

The nigrostriatal degeneration underlying Parkinson’s disease (PD) is commonly studied in experimental animals by injection of the neurotoxin 6-hydroxydopamine. The present study describes a modified version of a beam traversal test which allows the quantification of the motor deficit through the time spent to arrive to the platform once all four paws of the animals are in contact with the beam (escape latency, EL), the time spent before falling (tumbled down latency, TDL) and the number of errors (NE) committed for the animals in each beam. The shape and the diameter of the cross section of the beams were modified from rectangular and circular cross section with 2,5 cm of diameter to the same shape with 1 cm of diameter, which induced a high difficulty to the execution of the test. Three groups of Wistar rats were examined: untreated (n=15), lesioned with 6-hydroxydopamine (n=14), and sham-operated (n=14). All variables studied showed significant differences between control and hemiparkinsonian rats. The EL and the NE were increased and the TDL was decreased in hemiparkinsonian rats for all beams in comparison with control rats. In TDL the significant differences between groups were more evident (p<0.001) for the beams with high cross section irrespective of the shape of the cross section. BTT is a convenient sensorimotor test that does not need to be trained extensively, and require adverse motivation or food deprivation and appears to be very useful in evaluating the motor deficits in established unilateral model of PD and also other experimental models.

Nerve growth factor and striatal glutathione metabolism in a rat model of Huntingtonïs disease

Purpose. To test the influence of nerve growth factor (NGF) on striatal glutathione (GSH) content and the activities of GSH-related enzymes from quinolinic acid-lesioned rats. Methods. Rats were intrastriatally injected with QA and NGF. Enzymatic and GSH assays were performed one week later. Resuts. NGF prevented the QA-induced decline in glutathione reductase activity and GSH content. Conclusions. NGF is able to prevent some of the disturbances induced by the excitotoxic insult in the striatal GSH metabolism(AU)

Quinolinic acid lesion induces changes in rat striatal glutathione metabolism

Although the involvement of oxidative mechanisms in thecytotoxicity of excitatory amino acids has been well documented, it is not known whether the instrastriatal injection of quinolinic acid (QA) induces changes in gluthatione (GSH) metabolism. In this work, the activities of the enzynes GSH reductase (GRD), GSH peroxidase (GPX), and GSH S-transferase (GST), as well as the GSH content, were studied in the striatum, hippocampus, and frontal cortex of rats 1 and 6 weeks following the instrastriatal injection of QA (225 nmol). One group of animals remained untreated. This lesion resulted in a 20 porciento decrease in striatal GRD activity at both the 1- and 6-week postlesion time. GSH related enzyme activities and GSH content from other areas outside the lesioned striatum were not affected. GST activation could represent a beneficial compensatory response to neurtralize some of the oxidant agents generated by the lesion. However, this effect together with the reduction in GRD activity could be the cause or a contributing factor to the observed QA-induced deficit in GSH availability and, consequently, further disrupt the oxidant homeostasis of the injured striatal tissue. Therefore, these results provide evidence that the in vivo excitotoxic injury to the brain might affect oxidant/antioxidant equilibrium by eliciting changes in gluthatione metabolism(AU)

NGF prevents changes in rat brain glutathione-related enzymes following transection of the septohippocampal pathway

The activities of the enzymes glutathione reductase (GRD), glutathione peroxidase (GPX), and glutathione S-transferase (GST) were studied in several rat brain areas following the aspirative transection of the septohippocampal pathway (fimbria fornix) and the administration of nerve growth factor (NGF) or cytochrome c. One group of animals remained untreated. This lesion resulted in a decreased hippocampal GRD and septal GST activities, as well as, in an increase in GPX activity from the frontal cortex, striatum, and septum, NGF prevented the lesion-induced changes in hippocampal GRD and septal GPX. These findings show that the insult resulting from the aspiration of the fimbria fornix bundle involves modifications in glutathione-related enzymes, and, therefore, in the antioxidant status of brain tissue. These changes in gluthatione metabolism could be a consequence of the oxidative damage to GRD and GST protein or represent a compensatory response of GPX to the oxidative threat. The restirubg effects if BGF ib aktered ebztne activities are possibly linked to its known neuroprotective action(AU)

Retrieval of overtrained place navigation during occlusion of one eye and ipsi- or contralateral blockade of relevant brain centers in rats

Place navigation engrams acquired with intact brain can be retrieved with either eye and are stored in both hemispheres. The retrieval circuitry was examined by testing an overtrained rat under lidocaine inactivation of the hippocampus, visual cortex, and superior colliculus. Thirty-three hooded rats with implanted cannulae aimed at the above structures were trained to find a target in the southwest quadrant of the pool. Retrieval was tested during occlusion of one eye alone or combined with ipsi-or contralateral blockade (1 æ4 por ciento lidocaine) of hippocampus, hippocampus and visual cortes, or hippocampus, visual cortex, and superior colliculus. The intact brain escape latencies (9,8 s) were only slightly prolonged by occlusion of one eye (to 12,6 s). Blockade of centers ipsi/ or contralateral to the occluded eye increased escape latencies to 12,7 or 15,2 s for hippocampus, to 16,8 or 16,9 s for hippocampus and visual cortex, and to 23,6 or 17,4 s for hippocampus, visual cortex, and superior colliculus, respectively. Significant asymmetry appearing in the last case indicates that the superior colliculus plays an important role in mediation of the crossed visual input supporting place navigation. Residual goal-finding capacity in rats with blockade of centers ipsilateral to the occluded eye is probably due to uncrossed visual projections to the intact hemisphere(AU)

Retrieval of overtrained place navigation during occlusion of one eye and ipsi- or contralateral blockade of relevant brain centers in rats

Place navigation engrams acquired with intact brain can be retrieved with either eye and are stored in both hemispheres. The retrieval circuitry was examined by testing an overtrained rat under lidocaine inactivation of the hippocampus, visual cortex, and superior colliculus. Thirty-three hooded rats with implanted cannulae aimed at the above structures were trained to find a target in the southwest quadrant of the pool. Retrieval was tested during occlusion of one eye alone or combined with ipsi-or contralateral blockade (1 æ4 por ciento lidocaine) of hippocampus, hippocampus and visual cortes, or hippocampus, visual cortex, and superior colliculus. The intact brain escape latencies (9,8 s) were only slightly prolonged by occlusion of one eye (to 12,6 s). Blockade of centers ipsi/ or contralateral to the occluded eye increased escape latencies to 12,7 or 15,2 s for hippocampus, to 16,8 or 16,9 s for hippocampus and visual cortex, and to 23,6 or 17,4 s for hippocampus, visual cortex, and superior colliculus, respectively. Significant asymmetry appearing in the last case indicates that the superior colliculus plays an important role in mediation of the crossed visual input supporting place navigation. Residual goal-finding capacity in rats with blockade of centers ipsilateral to the occluded eye is probably due to uncrossed visual projections to the intact hemisphere(AU)

Retrieval of overtrained place navigation during occlusion of one eye and ipsi- or contralateral blockade of relevant brain centers in rats

Place navigation engrams acquired with intact brain can be retrieved with either eye and are stored in both hemispheres. The retrieval circuitry was examined by testing an overtrained rat under lidocaine inactivation of the hippocampus, visual cortex, and superior colliculus. Thirty-three hooded rats with implanted cannulae aimed at the above structures were trained to find a target in the southwest quadrant of the pool. Retrieval was tested during occlusion of one eye alone or combined with ipsi-or contralateral blockade (1 æ4 por ciento lidocaine) of hippocampus, hippocampus and visual cortes, or hippocampus, visual cortex, and superior colliculus. The intact brain escape latencies (9,8 s) were only slightly prolonged by occlusion of one eye (to 12,6 s). Blockade of centers ipsi/ or contralateral to the occluded eye increased escape latencies to 12,7 or 15,2 s for hippocampus, to 16,8 or 16,9 s for hippocampus and visual cortex, and to 23,6 or 17,4 s for hippocampus, visual cortex, and superior colliculus, respectively. Significant asymmetry appearing in the last case indicates that the superior colliculus plays an important role in mediation of the crossed visual input supporting place navigation. Residual goal-finding capacity in rats with blockade of centers ipsilateral to the occluded eye is probably due to uncrossed visual projections to the intact hemisphere(AU)