The hypothesis that early degeneration of the pedunculopontine nucleus (PPN) may be related to nigral degeneration has opened new avenues of basic research for this disease. It is not known how the motor function and nigrostriatal gene expression of TH, VMAT2 and DAT behave in an intermediate term (30 days) following the pontine 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.

Introducción. El núcleo pedunculopontino (NPP) desempeña un papel esencial en el control motor. La literatura sugiere que el NPP participa en el inicio y progresión de la enfermedad de Parkinson, y que su degeneración temprana precede a la muerte de las neuronas dopaminérgicas. Objetivos: determinar el efecto de la lesión neurotóxica del NPP sobre la función motora, la homeostasis oxidante nigroestriatal y la expresión génica de proteínas responsables de la homeostasis dopaminérgica. Métodos. La ejecución motora se evaluó mediante las pruebas de la barra transversal, del cilindro y de la huella. Se estudiaron la actividad enzimática catalasa (CAT), colinesterasa (AChE AE) y las concentraciones de malondialdehído (MDA) y glutatión (GSH). Los estudios moleculares contemplaron la expresión del ARNm de la tirosina hidroxilasa (TH), transportador vesicular de dopamina (VMAT), factor neurotrófico derivado del cerebro (BDNF) y transportador de dopamina (DAT). Resultados. Los estudios conductuales revelaron leves trastornos de la coordinación y cambios sutiles de la deambulación de las ratas con lesión pontina. Los estudios bioquímicos mostraron un incremento de la actividad CAT y de las concentraciones de MDA y GSH. Los estudios moleculares demostraron un incremento transitorio de la expresión nigral de BDNF y TH junto a una disminución de la expresión génica de VMAT y DAT.

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.

La presente propuesta aborda por primera vez en Cuba el estudio del trasplante de celulas mononucleares de medula osea (CMMO) en un modelo experimental de la enfermedad de Huntington (EH) en ratas, con el objetivo de evaluar el posible efecto protector de las CMMO trasplantadas sobre la funcion cognitiva y la conducta motora, asi como, los cambios morfologicos y moleculares que aparecen en el modelo. Se emplearon tecnicas de cirugia estereotactica, histoquimicas e inmunohistoquimicas, ensayo inmunoenzimatico, cromatografia liquida de alta resolucion, tecnicas de biologia molecular y estudios conductuales. La EH es un trastorno de origen hereditario con cambios en la esfera conductual, cognoscitiva y psiquiatrica. La inyeccion de acido quinolinico (AQ) en el estriado ha sido utilizada como modelo experimental de la EH. El tratamiento farmacologico en estos pacientes, constituye un proceder paliativo, por lo que en la actualidad no existe una terapia efectiva que permita curar la enfermedad. Todo lo anterior justifica la necesidad de desarrollar nuevas alternativas terapeuticas que mejoren, sustituyan o refuercen la perdida neuronal que se produce en el cerebro de estos enfermos. El Centro Internacional de Restauracion Neurologica (CIREN) tiene experiencia de mas de dos decadas en la reproduccion del modelo experimental de EH lo cual constituye una fortaleza para evaluar desde el punto de vista preclinico una alternativa terapeutica para estos pacientes. A nivel mundial se trabaja con modelos que abordan diferentes aspectos que van desde los mecanismos productores de la enfermedad hasta la evaluacion de estrategias de intervencion tal como el trasplante de celulas madre. En nuestro estudio demostramos que la inyeccion de AQ en el estriado induce una perdida neuronal que se traduce en trastornos cognitivos y motores y que las CMMO trasplantadas son capaces de sobrevivir, desarrollarse y tener un efecto positivo sobre la recuperacion del tejido lesionado con AQ demostrado histologicamente asi como conductual y cognitivamente. Esto se encuentra posiblemente relacionado con la capacidad del trasplante de restablecer la actividad neuroquimica y modificar la expresion genica y las concentraciones de BDNF. Por otra parte, se demostro en las celulas trasplantadas, la expresion de NeuN, asi como de GAD, lo que sugiere la diferenciacion de ellas a un fenotipo neuronal gabaergico que sustentaria la utilidad del trasplante de CMMO como alternativa de tratamiento para los pacientes con EH.

La enfermedad de Parkinson (EP) es una enfermedad neurodegenerativa que afecta aproximadamente 9,5/1000 personas mayores de 65 anos. Es una enfermedad con una incidencia creciente en Cuba y una de las primeras causas de atencion medica en el CIREN. Debido a su caracter progresivo se hace necesaria la comprension de los mecanismos moleculares involucrados en el dano neuronal que en la actualidad no estan bien dilucidados. Trabajos recientes han demostrado que el mantenimiento de la concentracion de GSH es esencial para proteger a la SNpc de la neurodegeneracion. Sin embargo, el efecto directo de la disminucion del GSH sobre la supervivencia de la celula dopaminergica y la conducta motora no ha sido esclarecido in vivo . De ahi que el objetivo de este trabajo fue determinar el efecto de la disminucion transitoria de la concentracion de glutation sobre el funcionamiento de la substantia nigra pars compacta (SNpc) y la conducta motora de ratas. La administracion unica por cirugia estereotactica de L-butionina sulfoximina en la SNpc produjo disminucion transitoria de la concentracion de glutation nigral y estriatal, lo que constituye un modelo valido para estudiar el papel de esta molecula en el sistema nervioso central. La evaluacion conductual demostro, por primera vez, que la disminucion transitoria de la concentracion de glutation nigral produce alteraciones en la conducta motora de ratas, lo que evidencio la importancia de este antioxidante para el funcionamiento del sistema motor de ratas. Estos cambios conductuales se acompanaron de muerte de neuronas dopaminergicas en la SNpc y cambios en la expresion de genes relacionados con la plasticidad del sistema nigro-estriatal. Por otra parte, la disminucion transitoria de la concentracion de glutation resulta en una acumulacion de oxido nitrico y alteracion de la senalizacion redox hacia la activacion de los mecanismos de apoptosis, asi como un desbalance en los mecanismos de neuroinflamacion que pueden contribuir a perpetuar el dano en esta estructura.

Huntington's disease (HD) is an inherited, neurodegenerative disorder that results from the degeneration of striatal neurons, mainly GABAergic neurons. The study of neurochemical activity has provided reliable markers to explain motor disorders. To treat neurodegenerative diseases, stem cell transplants with bone marrow (BM) have been performed for several decades. In this work we determine the effect of mononuclear bone marrow cell (mBMC) transplantation on the rotational behavior and neurochemical activity in a model of Huntington's disease in rats. Four experimental groups were organized: Group I: Control animals (n = 5); Group II: Lesion with quinolinic acid (QA) in the striatum (n = 5); Group III: Lesion with QA and transplant with mBMC (n = 5); Group IV: Lesion with QA and transplant with culture medium (Dulbecco's modified Eagle's medium (DMEM) injection) (n = 5). The rotational activity induced by D-amphetamine was evaluated and the concentration of the neurotransmitter amino acids (glutamate and GABA) was studied. The striatal cell transplantation decreases the rotations induced by D-amphetamine (p < 0.04, Wilcoxon matched pairs test) and improves the changes produced in the levels of neurotransmitters studied. This work suggests that the loss of GABAergic neurons in the brain of rats lesioned with AQ produces behavioral and neurochemical alterations that can be reversed with the use of bone marrow mononuclear cell transplants.

The aims of the present work were to evaluate the exploratory activity in Sprague-Dawley rats, as well as to analyze the nigral and striatal mRNA expression of the plasticity-related genes bdnf and arc after L-buthionine sulfoximine (BSO) injection into substantia nigra compacta. Lesioned rats traveled less distance in open field but did not show a decline in the novel object recognition test. On the other hand, RT-PCR analysis showed over expression of striatal arc 24 h post-lesion; no significant changes in bdnf expression were observed in nigral or striatal tissue. These results suggest that intranigral BSO injection causes impairment in exploratory behavior in these rats, by affecting locomotion, which is associated with changes in striatal synaptic plasticity.

The purpose of the present study is to access the linkage between dysregulation of glutamatergic neurotransmission, oxidative metabolism, and serine signaling in age-related cognitive decline. In this work, we evaluated the effect of natural aging in rats on the cognitive abilities for hippocampal-dependent tasks. Oxidative metabolism indicators are glutathione (GSH), malondialdehyde (MDA) concentrations, and cytosolic phospholipase A2 (PLA2) activity. In addition, neurotransmitter amino acid (L-Glutamic acid, γ-aminobutyric acid (GABA), DL-Serine and DL-Aspartic acid) concentrations were studied in brain areas such as the frontal cortex (FC) and hippocampus (HPC). The spatial long-term memory revealed significant differences among experimental groups: the aged rats showed an increase in escape latency to the platform associated with a reduction of crossings and spent less time on the target quadrant than young rats. Glutathione levels decreased for analyzed brain areas linked with a significant increase in MDA concentrations and PLA2 activity in cognitive-deficient old rats. We found glutamate levels only increased in the HPC, whereas a reduced level of serine was found in both regions of interest in cognitive-deficient old rats. We demonstrated that age-related changes in redox metabolism contributed with alterations in synaptic signaling and cognitive impairment.

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.

•Transient glutathione depletion causes cognitive impairment in rats.•Cognitive impairment is associated with a selective vulnerability of hippocampus to maintain redox homeostasis.•Glutathione depletion generates glial activation and neuroinflammation correlated with a subtle cognitive deficit.

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.

Glutathione (GSH) deficiency has been identified as an early event in the progression of Parkinson's disease. However, the role of GSH in the etiology and pathogenesis of this neurodegenerative disorder is not well established. The aim of this study is to assess the effect of transient GSH depletion in the substantia nigra pars compacta (SNpc) on neuroinflammation after the injection of a single dose of l-buthionine sulfoximine (BSO) into the SNpc of male Sprague-Dawley rats. The results showed that BSO treatment stimulates microglia (p<0.01) and astroglial response (p<0.01), c-Jun N-terminal kinase and inducible nitric oxide synthase (iNOS) (p<0.001) in the SNpc, accompanied by dopaminergic dysfunction. In addition, high levels of tumor necrosis factor α (p<0.01), interleukins IL-1β p<0.01), IL-6 p<0.001) and nitric oxide p<0.01) were found in the treated animals compared to control groups, while no significant differences were found in IL-10 levels. These results suggest that transient GSH depletion can increase the susceptibility of SNpc to degeneration by promoting an inflammatory response and nitrosative stress, reinforcing the possible role of GSH unbalance, oxygen/nitrogen reactive species and neuroinflammation as causal factors on the degeneration of the SNpc.

INTRODUCCION: La esclerosis multiple es una enfermedad inflamatoria cronica del sistema nervioso central caracterizada por areas generalizadas de desmielinizacion focal. El modelo animal principalmente utilizado es la encefalomielitis autoinmune experimental. OBJETIVO: Demostrar los efectos del tratamiento con ficocianobilina y sus combinaciones. La PCB es una biliproteina derivada de la cianobacteria Spirulina platensis. METODOS: Se indujo EAE en ratones C57BL / 6 con MOG35–55 en adyuvante completo de Freund/emulsion de Mycobacterium tuberculosis y la toxina pertussis. En este modelo fue evaluado el efecto de la PCB/IFNbeta en comparacion con los ingredientes activos de forma independiente. La progresion clinica diaria fue evaluada, y se determinaron, mediante ELISA, las concentraciones de CCL5, CXCL10, IFN–γ, CXCL2, CCL2, IL–17A, IL–6 e IL–10 en homogeneizados de tejido. RESULTADOS: Los ratones con EAE tratados con la combinacion PCB/IFN–beta mostraron una disminucion significativa de la puntuacion clinica. Por otro lado, el tratamiento de combinacion PCB/IFN–beta indujo una disminucion significativa de los niveles de IL–10 y IL–17 en homogeneizados de cerebro. CONCLUSION: La combinacion PCB/IFN–beta aminora la progresion clinica de la enfermedad EAE, un efecto posiblemente mediado en el cerebro por una disminucion de los niveles de IL–17A e IL–10.

This article investigates the possible effects of transplantation of mononuclear bone marrow cells (mBMCs) to ameliorate or prevent the behavioral impairments and the cellular damage observed in a quinolinic acid (QA) model of Huntington's disease. mBMCs were isolated using a standard procedure and implanted within the QA-lesioned striatum. Behavior was explored using motor (beam test) and memory (object recognition and Morris water maze) tests. Morphology was evaluated using conventional histology (cresyl violet), bisbenzimide (to evaluate cell vitality), and immunohystochemistry to identify neurons or glia. mBMC-transplanted animals showed improvements in motor coordination (beam test). Regarding memory, object recognition was significantly improved in transplanted animals, while spatial memory (Morris water maze test) was not severely affected by QA and, therefore, the results after transplantation were significant only in the probe-trial retention test. In samples taken from the animals that participated in the behavioral tests, a preserved morphology of striatal neurons and a reduced glial reaction indicated a possible neuroprotective effect of the transplanted mBMCs. A parallel study confirmed that the transplanted mBMCs have a long survival period (1 year follow-up). The results presented confirm the possibility that mBMC transplantation may be a viable therapeutic option for Huntington's disease.

Glutathione is the major antioxidant in the living cells. Its deficit has been linked to neurodegenerative disorders as Parkinson's disease but its role in the etiology of nigral degeneration and sensory-motor performance has been poorly explored. To evaluate the effect of glutathione depletion on nigro-striatal oxidative metabolism and sensory-motor performance in rats, l-buthionine sulfoximine (15 mM) or saline solution was injected into substantia nigra pars compacta (SNpc). Then, oxidative metabolism was studied 24h and 7 days later in SNpc and corpus striatum (CS). Tyrosine hydroxylase and GFAP immunohistochemistry assays were carried out at 7 days. In addition, animals were evaluated in open field, adhesive removal, staircase and traverse beam tests. Glutathione depletion induced compensatory response in catalase activity and glial response in the in SNpc and no oxidative damage was observed. However, a loss in dopaminergic cells was found. At the same time, animals with glutathione depletion have shown poor performance in behavioral tests except for staircase test. These results suggest that glutathione depletion can be related to sensory-motor dysfunction.

Cerebral ischemia is a major cause of death, for this reason animal models of cerebral ischemia are widely used to study both the pathophysiology of ischemic phenomenon and the evaluation of possible therapeutic agents with protective or regenerative properties. The objectives of this study were to examine the presence of neuronal damage in different brain areas following the ischemic event, and assess consequences of such activities on the processes of memory and learning. The study group included an experimental group ischemic animals (30 rats with permanent bilateral occlusion of the carotids), and a control group. Was evaluated gene expression and inflammatory ischemic by qPCR techniques 24h post injury, brain tissue morphology in areas of cortex, striatum and hippocampus seven days post injury and processes of memory and learning, 12 days post injury. The morphological studies showed that the procedure induces death of cell populations in cortex, striatum and hippocampus, ischemia modified gfap gene expression and ho, il-6, il-17 and ifn-gamma, which can be used as a marker of early ischemic process. Additionally, the ischemic injury caused spatial memory decline. This characterization gives us an experimental model to develop future studies on the pathophysiology of ischemic events and assessing therapeutic strategies.

Deep brain stimulation (DBS) has become the standard surgical procedure for advanced Parkinson's disease (PD). Recently, the pedunculopontine tegmental nucleus (PPN) has emerged as a potential target for DBS in patients whose quality of life is compromised by freezing of gait and falls. To date, only a few groups have published their long-term clinical experience with PPN stimulation. Bearing in mind that the Barrington (Bar) nucleus and some adjacent nuclei (also known as the micturition centre) are close to the PPN and may be affected by DBS, the aim of the present study was to review the anatomical location of this structure in human and other species. To this end, the Bar nucleus area was analysed in mouse, monkey and human tissues, paying particular attention to the anatomical position in humans, where it has been largely overlooked. Results confirm that anatomical location renders the Bar nucleus susceptible to influence by the PPN DBS lead or to diffusion of electrical current. This may have an undesirable impact on the quality of life of patients.

Brain-derived neurotrophic factor (BDNF) concentration was measured in the striatum and cortex after quinolinic acid intrastriatal lesion and transplantation of bone marrow cells (BMSC). The results showed a significant increase of the BDNF levels in the striatum and cortex of the lesioned animals and the ability of the transplanted cells to increase the levels of BDNF in both sites. This recovery of BDNF production and distribution might have beneficial effects and ameliorate the negative consequences of the striatal lesion, a mechanism of potential interest for the treatment of Huntington's disease (HD).

In Down's syndrome there is evidence that increased gene expression coding for specific cystathionine beta-synthase translates directly into biochemical aberrations, which result in a biochemical and metabolic imbalance of the methyl status. This event is destined to impact mitochondrial function since methylation is a necessary event in mitochondria and relies on the availability and uptake of the methyl donor S-adenosylmethionine. Indeed mitochondrial dysfunctions have been widely described in Down's syndrome, but they have never been correlated to a possible mitochondrial methyl unbalance. In the present study we find that the mitochondrial levels of S-adenosylmethionine are reduced in Down's syndrome compared to control cells demonstrating the effect of the methyl unbalance on mitochondria. The possible role of methylation in mitochondria is discussed and some preliminary results on a possible methylation target are presented.