Basolateral amygdala stimulation does not recruit LTP at depotentiated synapses.

Hippocampal long-term potentiation (LTP) is a long-lasting increase in synaptic efficacy considered to be the cellular basis of memory. LTP consists of an early, protein synthesis-independent phase (E-LTP) and a late phase that depends on protein synthesis (L-LTP). Application of a weak tetanus can induce E-LTP in the dentate gyrus (DG) which can be reinforced into L-LTP by direct stimulation of the basolateral amygdala (BLA) within 30 min before or after LTP induction (structural LTP-reinforcement). LTP can be depotentiated by low-frequency stimulation (LFS) to the same synaptic input if applied shortly after tetanization (<10 min). Here, we addressed the question of whether stimulation of the BLA is able to recover LTP at depotentiated synaptic inputs. We hypothesized that E-LTP can activate synaptic tags, which were then reset by depotentiation. Stimulation of the BLA thereafter could beneficially act on tag-reactivation as well as on the activation of the synthesis of plasticity-related proteins (PRPs), normally captured by the tags and thus transforming E-LTP into L-LTP. Our results show, that BLA-stimulation was not able to reactivate the resetting of tags by depotentiation in the DG of freely moving rats.

[Evaluation of the survival of bone marrow mononucleate cells transplanted in a rat model of striatal lesion with quinolinic acid]. / Evaluacion de la supervivencia de las células mononucleadas de la médula ósea trasplantadas en un modelo de ratas con lesión estriatal por ácido quinolínico.

INTRODUCTION: Transplant is one of the alternatives available for the treatment of neurodegenerative diseases aimed at replacing the cells lost during the course of the disease. One promising source of cells for the development of transplants could be the mononucleate cells from bone marrow. AIMS. The purpose of this study was to study the capacity of bone marrow mononucleate cells to survive the transplant process, and to search for a method that enables tracking of these cells in vivo once they have been implanted. MATERIALS AND METHODS: Bone marrow mononucleate cells were extracted from the femur of rats by means of a Ficoll-Hypaque gradient. The cells under study were modified genetically with an adenovirus that expresses the PFV or which are marked with Hoechst dye. The marked cells were implanted in the striatum of rats with lesions caused by quinolinic acid. RESULTS: The viability of the genetically modified cells was low, whereas that of the cells marked with Hoechst dye was above 90%. The implanted cells survived the transplant at least a month and dispersed away from the site of entry towards the corpus callosum and cortex. CONCLUSIONS: We consider that the use of Hoechst dye offers more advantages for tracking these cells in vivo. Mononucleate cells have a number of characteristics that allow them to be included as candidate sources of cells for the treatment of neurodegenerative diseases.

Evaluación de la supervivencia de las células mononucleadas de la médula ósea trasplantadas en un modelo de ratas con lesión estriatal por ácido quinolínico / Evaluation of the survival of bone marrow mononucleate cells transplanted in a rat model of striatal lesion with quinolinic acid

Introducción. El trasplante es una de las alternativas para el tratamiento de enfermedades neurodegenerativas, y está encaminado hacia el reemplazo de las células perdidas durante el desarrollo de la enfermedad. Una fuente celular prometedora para el desarrollo de los trasplantes podrían ser las células mononucleadas de la médula ósea. Objetivo. Estudiar la capacidad de las células mononucleadas de la médula ósea de sobrevivir al trasplante y buscar un método que permita el seguimiento de estas células in vivo una vez implantadas. Materiales y métodos. Las células mononucleadas fueron extraídas del fémur de ratas mediante un gradiente de Ficoll-Hypaque. Las células objeto de estudio fueron modificadas genéticamente con un adenovirus que expresa la PFV o marcadas con el reactivo de Hoechst. Las células marcadas se implantaron en el estriado de ratas lesionadas con ácido quinolínico. Resultados. La viabilidad de las células modificadas genéticamente fue baja, mientras que la de las células marcadas con el reactivo de Hoechst fue superior al 90%. Las células implantadas sobrevivieron al trasplante al menos un mes y se dispersaron desde el sitio de entrada hacia el cuerpo calloso y la corteza. Conclusiones. Consideramos más ventajoso el uso del reactivo de Hoechst para el seguimiento de estas células in vivo. Las células mononucleadas tienen características que les permiten formar parte de las fuentes celulares candidatas para el tratamiento de las enfermedades neurodegenerativas

Introduction. Transplant is one of the alternatives available for the treatment of neurodegenerative diseases aimed at replacing the cells lost during the course of the disease. One promising source of cells for the development of transplants could be the mononucleate cells from bone marrow. Aims. The purpose of this study was to study the capacity of bone marrow mononucleate cells to survive the transplant process, and to search for a method that enables tracking of these cells in vivo once they have been implanted. Materials and methods. Bone marrow mononucleate cells were extracted from the femur of rats by means of a Ficoll-Hypaque gradient. The cells under study were modified genetically with an adenovirus that expresses the PFV or which are marked with Hoechst dye. The marked cells were implanted in the striatum of rats with lesions caused by quinolinic acid. Results. The viability of the genetically modified cells was low, whereas that of the cells marked with Hoechst dye was above 90%. The implanted cells survived the transplant at least a month and dispersed away from the site of entry towards the corpus callosum and cortex. Conclusions. We consider that the use of Hoechst dye offers more advantages for tracking these cells in vivo. Mononucleate cells have a number of characteristics that allow them to be included as candidate sources of cells for the treatment of neurodegenerative diseases

Evaluación de la supervivencia de las células mononucleadas de la médula ósea trasplantadas en un modelo de ratas de lesión estriatal con ácido quinolínico / Evaluation of the survival of bone marrow mononucleate cells transplanted in a rat model of striatal lesion with quinolinic acid

Introducción. El trasplante es una de las alternativas para el tratamiento de enfermedades neurodegenerativas, y está encaminado hacia el reemplazo de las células perdidas durante el desarrollo de la enfermedad. Una fuente celular prometedora para el desarrollo de los trasplantes podrían ser las células mononucleadas de la médula ósea. Objetivo. Estudiar la capacidad de las células mononucleadas de la médula ósea de sobrevivir al trasplante y buscar un método que permita el seguimiento de estas células in vivo una vez implantadas. Materiales y métodos. Las células mononucleadas fueron extraídas del fémur de ratas mediante un gradiente de Ficoll-Hypaque. Las células objeto de estudio fueron modificadas genéticamente con un adenovirus que expresa la PFV o marcadas con el reactivo de Hoechst. Las células marcadas se implantaron en el estriado de ratas lesionadas con ácido quinolínico. Resultados. La viabilidad de las células modificadas genéticamente fue baja, mientras que la de las células marcadas con el reactivo de Hoechst fue superior al 90 por ciento. Las células implantadas sobrevivieron al trasplante al menos un mes y se dispersaron desde el sitio de entrada hacia el cuerpo calloso y la corteza. Conclusiones. Consideramos más ventajoso el uso del reactivo de Hoechst para el seguimiento de estas células in vivo. Las células mononucleadas tienen características que les permiten formar parte de las fuentes celulares candidatas para el tratamiento de las enfermedades neurodegenerativas(AU)

Introduction: Transplant is one of the alternatives available for the treatment of neurodegenerative diseases aimed at replacing the cells lost during the course of the disease. One promising source of cells for the development of transplants could be the mononucleate cells from bone marrow. AIMS. The purpose of this study was to study the capacity of bone marrow mononucleate cells to survive the transplant process, and to search for a method that enables tracking of these cells in vivo once they have been implanted. MATERIALS AND METHODS: Bone marrow mononucleate cells were extracted from the femur of rats by means of a Ficoll-Hypaque gradient. The cells under study were modified genetically with an adenovirus that expresses the PFV or which are marked with Hoechst dye. The marked cells were implanted in the striatum of rats with lesions caused by quinolinic acid. RESULTS: The viability of the genetically modified cells was low, whereas that of the cells marked with Hoechst dye was above 90percent. The implanted cells survived the transplant at least a month and dispersed away from the site of entry towards the corpus callosum and cortex. CONCLUSIONS: We consider that the use of Hoechst dye offers more advantages for tracking these cells in vivo. Mononucleate cells have a number of characteristics that allow them to be included as candidate sources of cells for the treatment of neurodegenerative diseases

[Survival of dopaminergic neurons that were hibernated in vitro for seven days]. / Supervivencia in vitro de neuronas dopaminérgicas hibernadas durante siete días.

INTRODUCTION: The use of fresh foetal tissue in neurotransplants entails considerable problems of logistics that limit its clinical applicability, something that can be resolved by the development of optimal tissue storage procedures that do not affect in vivo viability and survival of dopamine. AIMS. To determine whether 7 days' hibernation affects the survival of mesencephalic tissue in vitro, and to compare it to fresh tissue. MATERIALS AND METHODS: The midbrains of rats were hibernated for 1, 3, 5 and 7 days at 4 degrees C. A cellular suspension was prepared for culture throughout a 7-day period. The number of TH+ cells present in the fresh and hibernated cultures was determined. RESULTS: The morphology of the hibernated and cultured dopaminergic neurons was very similar to that of the fresh cells. Comparing the viability of the hibernated and fresh cells did not reveal any significant differences. No significant differences between the numbers of TH+ neurons were observed at any of the hibernation times. The lowest rate of TH+ cell survival was reached at seven days' hibernation. Significant differences (p < 0.05) were found between the number of TH+ neurons for fresh and hibernated tissue. CONCLUSIONS: Hibernation at 4 degrees C for up to five days guarantees the survival of TH+ cells in vitro, but it is affected by longer times. This procedure could be considered useful for preserving human tissue in clinical transplant applications. These results refer to in vitro conditions; therefore, studies must be conducted to investigate the survival and functionality of hibernated and transplanted neurons in animal models to enable us to evaluate its applicability in neurorestorative therapy.

[The effects of lesions in the compact part of the substantia nigra on glutamate and GABA release in the pedunculopontine nucleus]. / Efecto de la lesión de la sustancia negra pars compacta sobre la liberación de glutamato y GABA en el núcleo pedunculopontino.

INTRODUCTION: The pedunculopontine nucleus (PPN), co-localized with the mesencephalic locomotor region, has been proposed as a key structure in the physiopathology of Parkinson's disease. OBJECTIVES: The goal of the present study was to assess if the aminoacid neurotransmitter release in the PPN is modified by the degeneration of dopaminergic cells, from substantia nigra pars compacta in 6-hydroxidopamine (6-OHDA)-lesioned rats. In addition, it was studied the aminoacid neurotransmitter release in the PPN of rats with lesion of the subthalamic nucleus by quinolinic acid (QUIN) (100 nmol) intracerebral injection. MATERIALS AND METHODS: Rats were assigned to five groups: untreated rats (I) (n = 13), 6-OHDA lesion (II) (n = 11), 6-OHDA + QUIN lesion (III) (n = 9), sham-operated (IV) (n = 10), QUIN, STN (V) lesioned (n = 9). The extracellular concentrations of glutamic acid (GLU) and gamma-aminobutyric acid (GABA) were determined by brain microdialysis and high performance liquid chromatography (HPLC). RESULTS. GLU released in PPN from 6-OHDA lesioned rats (group II), was significantly increased in comparison with the others groups (F(4, 47) = 18.21, p < 0.001). GABA released shows significant differences between experimental groups (F(4, 45) = 12.75, p < 0.001). It was detected a higher valour (p < 0.05) in-group II. The groups III and IV exhibited intermeddle valour (p < 0.001) and groups I and IV (p < 0.001) showed the lower GABA extracellular concentrations. The infusion of artificial cerebrospinal fluid with higher potassium (100 mmol) induced an increase in the GLU and GABA released in all groups, which confirm the neuronal origin of the extracellular content. CONCLUSION: These results are in agreement with the current model of basal ganglia functioning and suggest the role of STN-PPN projection in the physiopathology of Parkinson's disease.

Supervivencia in vitro de neuronas dopaminérgicas hibernadas durante siete días / Survival of dopaminergic neurons that were hibernated in vitro for seven days

Introducción. El uso de tejido fetal fresco en el neurotrasplante presenta considerables dificultades logísticas que limitan su aplicabilidad clínica. Este aspecto podría solucionarse con el desarrollo de procedimientos óptimos de almacenamiento del tejido que no afecten a la viabilidad y la supervivencia dopaminérgica in vivo. Objetivo. Determinar si la hibernación durante siete días influye sobre la supervivencia del tejido mesencefálico in vitro, y comparar el tejido hibernado con el fresco. Material y métodos. El mesencéfalo de rata se hibernó 1, 3, 5 y 7 días a 4 °C. Se preparó la suspensión celular para cultivar durante siete días. Se determinó el número de células TH+ presentes en los cultivos frescos e hibernados. Resultados. La morfología de las neuronas dopaminérgicas hibernadas y cultivadas fue muy similar a la de las células frescas. La comparación de la viabilidad de las células hibernadas con la de las frescas mostró diferencias no significativas. No hay diferencias significativas entre el número de neuronas TH+ observadas en todos los tiempos de hibernación. La supervivencia de células TH+ más baja se alcanzó a los siete días de hibernación. Existen diferencias significativas (p < 0,05) entre el número de neuronas TH+ del tejido fresco y el hibernado. Conclusiones. La hibernación a 4 °C hasta cinco días garantiza la supervivencia in vitro de las células TH+; tiempos mayores, la afecta. Este procedimiento podría considerarse útil para la conservación del tejido humano aplicable en el trasplante clínico. Estos resultados se refieren a condiciones in vitro; por tanto, se requiere estudiar la sobrevivencia y funcionalidad de las neuronas hibernadas y trasplantadas en modelos animales para evaluar su aplicación en la terapia neurorrestaurativa

Introduction. The use of fresh foetal tissue in neurotransplants entails considerable problems of logistics that limit its clinical applicability, something that can be resolved by the development of optimal tissue storage procedures that do not affect in vivo viability and survival of dopamine. Aims. To determine whether 7 days’ hibernation affects the survival of mesencephalic tissue in vitro, and to compare it to fresh tissue. Materials and methods. The midbrains of rats were hibernated for 1, 3, 5 and 7 days at 4 °C. A cellular suspension was prepared for culture throughout a 7-day period. The number of TH+ cells present in the fresh and hibernated cultures was determined. Results. The morphology of the hibernated and cultured dopaminergic neurons was very similar to that of the fresh cells. Comparing the viability of the hibernated and fresh cells did not reveal any significant differences. No significant differences between the numbers of TH+ neurons were observed at any of the hibernation times. The lowest rate of TH+ cell survival was reached at seven days’ hibernation. Significant differences (p < 0.05) were found between the number of TH+ neurons for fresh and hibernated tissue. Conclusions. Hibernation at 4 °C for up to five days guarantees the survival of TH+ cells in vitro, but it is affected by longer times. This procedure could be considered useful for preserving human tissue in clinical transplant applications. These results refer to in vitro conditions; therefore, studies must be conducted to investigate the survival and functionality of hibernated and transplanted neurons in animal models to enable us to evaluate its applicability in neurorestorative therapy

Supervivencia in vitro de neuronas dopaminèrgicas hibernadas durante siete dias / s. t

El uso de tejido fetal fresco en el neurotrasplante presenta considerables dificultades logìsticas que limitan su aplicabilidad clìnica . Este aspecto podrìa solucionarse con el desarrollo de procedimientos optimos de almacenamiento del tejido que no afecten a la viabilidad y la supervivencia dopaminèrgica in vivo. Es objetivo del trabajao determinar si la hibernaciòn durante siete dìas influye sobre la supervivencia del tejido mesencefàlico in vitro y comparar el tejido hibernado con el fresco...(AU)

Efecto de la lesión de la sustancia negra pars compacta sobre la liberación de glutamato y GABA en el núcleo pedunculopontino / The effects of lesions in the compact part of the substantia nigra on glutamate and gaba release in the pedunculopontine nucleus

Introducción. El núcleo pedunculopontino (NPP), colocalizado con el área locomotora mesencefálica, se ha señalado como una estructura clave en la fisiopatología de la enfermedad de Parkinson. Objetivos. 1. Estudiar el efecto de la lesión de la sustancia negra pars compacta -por inyección de 6-hidroxidopamina (6-OHDA)- sobre la liberación de aminoácidos neurotransmisores en el NPP. 2. Estudiar el efecto de la lesión del núcleo subtalámico (NST), por inyección intracerebral de 100 nmol de ácido quinolínico (QUIN), sobre la liberación de aminoácidos neurotransmisores en el NPP. Materiales y métodos. Se organizaron cinco grupos experimentales: ratas sanas (I; n = 13), lesión con 6-OHDA (II; n = 11), lesión simultánea de 6-OHDA + QUIN (III; n = 9), falsa lesión de 6-OHDA (IV; n = 10), y lesión del NST con QUIN (V; n = 9). Las concentraciones extracelulares de ácido glutámico (GLU) y GABA se determinaron por medio de cromatografía líquida de alta resolución (HPLC) con detección fluorimétrica. Resultados. Se detectaron diferencias significativas en la liberación de GLU entre todos los grupos experimentales (F(4, 47) = 18,21, p < 0,001), con un aumento significativo de esta variable en el grupo II. La liberación de GABA en el NPP mostró diferencias significativas entre los grupos en estudio (F(4, 45) = 12,75, p < 0,001). Para esta variable se produjo una separación entre los grupos, con un aumento significativo (p < 0,05) en el grupo II, valores intermedios y significativamente diferentes para los grupos III y V (p < 0,001) y valores menores para los grupos I y IV. La infusión de una solución de líquido cefalorraquídeo artificial con mayor concentración de potasio (100 mmol) produjo un incremento en la liberación de los aminoácidos neurotransmisores en todos los grupos experimentales, lo cual confirma el origen neuronal del contenido extracelular estudiado. Conclusiones. Estos resultados concuerdan con el ‘modelo’ actual de funcionamiento de los ganglios basales y sugieren un papel importante a la proyección STN-NPP en la fisiopatología de la enfermedad de Parkinson

Introduction. The pedunculopontine nucleus (PPN), co-localized with the mesencephalic locomotor region, has been proposed as a key structure in the physiopathology of Parkinson’s disease. Objectives. The goal of the present study was to assess if the aminoacid neurotransmitter release in the PPN is modified by the degeneration of dopaminergic cells, from substantia nigra pars compacta in 6-hydroxidopamine (6-OHDA)-lesioned rats. In addition, it was studied the aminoacid neurotransmitter release in the PPN of rats with lesion of the subthalamic nucleus by quinolinic acid (QUIN) (100 nmol) intracerebral injection. Materials and methods. Rats were assigned to five groups: untreated rats (I) (n = 13), 6-OHDA lesion (II) (n = 11), 6-OHDA + QUIN lesion (III) (n = 9), sham-operated (IV) (n = 10), QUIN, STN (V) lesioned (n = 9). The extracellular concentrations of glutamic acid (GLU) and gamma-aminobutyric acid (GABA) were determined by brain microdialysis and high performance liquid chromatography (HPLC). Results. GLU released in PPN from 6-OHDA lesioned rats (group II), was significantly increased in comparison with the others groups (F(4, 47) = 18.21, p < 0.001). GABA released shows significant differences between experimental groups (F(4, 45) = 12.75, p < 0.001). It was detected a higher valour (p < 0.05) in-group II. The groups III and IV exhibited intermeddle valour (p < 0.001) and groups I and IV (p < 0.001) showed the lower GABA extracellular concentrations. The infusion of artificial cerebrospinal fluid with higher potassium (100 mmol) induced an increase in the GLU and GABA released in all groups, which confirm the neuronal origin of the extracellular content. Conclusion. These results are in agreement with the current model of basal ganglia functioning and suggest the role of STN-PPN projection in the physiopathology of Parkinson’s disease

Efecto de la lesión de la sustancia negra parte compacta sobre la liberación de glutamato y GABA en el núcleo pedunculopontino / The effects of lesions in the compact part of the substantia nigra on glutamate and GABA release in the pedunculopontine nucleus

The pedunculopontine nucleus (PPN), co-localized with the mesencephalic locomotor region, has been proposed as a key structure in the physiopathology of Parkinson's disease. OBJECTIVES: The goal of the present study was to assess if the aminoacid neurotransmitter release in the PPN is modified by the degeneration of dopaminergic cells, from substantia nigra pars compacta in 6-hydroxidopamine (6-OHDA)-lesioned rats. In addition, it was studied the aminoacid neurotransmitter release in the PPN of rats with lesion of the subthalamic nucleus by quinolinic acid (QUIN) (100 nmol) intracerebral injection...(AU)

[Lesions in the pars compacta substantiae nigra and the subthalamic nucleus modify the density of muscarinic receptors in different nuclei of the basal ganglia]. / La lesión de la sustancia negra pars compacta y del núcleo subtalámico modifica la densidad de receptores muscarínicos en distintos núcleos de los ganglios basales.

INTRODUCTION: Several studies that has focused to the dopaminergic transmission in the basal ganglia in parkinsonian condition, but only a few article has taking into account the imbalance between dopaminergic and cholinergic transmission. OBJECTIVE: To evaluate the muscarinic cholinergic receptors density in SNc and PPN in the 6-OHDA model. MATERIALS AND METHODS: Were organized five experimental groups in correspondence to the place of the lesion: I. Non treated rats, II. 6-OHDA lesion in SNc, III. 6-OHDA lesion in SNc + quinolinic acid lesion in NST, IV. Sham operated rats, V. Quinolinic acid in STN. Were obtained coronal sections of 20 microm thickness of SNc and PPN from rats and in these sections was evaluated the muscarinic receptors density through autoradiographic technique with [3H]quinuclidinylbenzilate (QNB) (1.23 nM). The muscarinic antagonist atropine (1 microM) was utilized as non-specific union. The density was evaluated in both hemispheres and the density optical was converted in fentomolas/mg of tissue with base to values obtained from tritium standards. RESULTS: Significant diminution of the muscarinic receptors density was found in the SNc ipsilateral to the 6-OHDA lesion from experimental groups II (t=2.76; p<0.05) and III (t=4.06; p<0.05). In the group V, was seen a significant increase of muscarinic receptor density in the SNc ipsilateral to the 6-OHDA lesion. The comparison between experimental groups evidenced significant differences among them (F=13.13; p<0.001) with a significant decrease in the density from SNc of groups II and III and significant increase in the density from SNc of group V in comparison of the others groups. In relation to PPN, muscarinic receptors density from right PPN ipsilateral to the 6-OHDA lesion, shown significant differences (F=3.93; p<0.01) between the experimental groups with a significant increase of this variable in the group II. CONCLUSIONS: These results signal a modification of cholinergic activity after 6-OHDA lesion. The changes in the muscarinic receptors populations located in SNc and PPN could be part of different compensatory mechanisms to attempt ameliorate the imbalance between dopaminergic and cholinergic transmission that it was installed after denervation of nigrostriatal forebrain bundle. The excitotoxic lesion of STN impose a new adjust mechanism for cell from PPN, which could be expressed in the changes of muscarinic cholinergic receptors population at the level of SNc.

La lesión de la sustancia negra pars compacta y del núcleo subtalámico modifica la densidad de receptores muscarínicos en distintos núcleos de los ganglios basales / Lesions in the pars compacta substantiae nigrae and the subthalamic nucleus modify the density of muscarinic receptors in different nuclei of the basal ganglia

Introducción. Numerosos estudios han abordado el papel de la neurotransmisión dopaminérgica en los ganglios basales en condiciones de parkinsonismo, pero pocos se han encaminado hacia el desequilibrio entre la trasmisión dopaminérgica y colinérgica. Objetivo. Evaluar la densidad de receptores colinérgicos muscarínicos en sustancia negra pars compacta (SNc) y núcleo pedunculopontino (NPP) en el modelo de 6-OHDA. Materiales y métodos. Se organizaron cinco grupos experimentales según la lesión de SNcyNST: 1. Animales sanos; 2. Ratas lesionadas con 6-OHDA; 3. Ratas con lesión simultánea de SNcyNST; 4. Ratas Sham del modelo de 6-OHDA; 5. Ratas con lesión de NST. Se obtuvieron cortes de 20 µm de grosor de SNc y NPP de ratas, en los cuales se evaluó la densidad de receptores colinérgicos muscarínicos por autorradiografía con [3H]quinuclidinilbencilato (QNB) (1,23 nM). Como unión no específica se usó el antagonista muscarínico atropina (1 µM). Se realizaron lecturas en los dos hemisferios y la densidad óptica se convirtió en fentomolas por mg de tejido con base en los valores obtenidos de los estándares de tritio. Resultados. En los grupos 2 (t = 2,76; p < 0,05) y 3 (t = 4,06; p < 0,05) se evidenció una disminución significativa de la densidad de receptores muscarínicos en la SNc ipsilateral a la lesión de 6-OHDA. El grupo 5 mostró un aumento significativo de la densidad de receptores muscarínicos en la SNc lesionada con 6-OHDA (t = 2,69; p < 0,05). La comparación entre grupos experimentales arrojó diferencias significativas entre éstos (F=13,13;p<0,001), con una disminución en los grupos 2 y 3 y un aumento significativo en el grupo 5, en relación con los restantes grupos. La densidad de receptores muscarínicos para el NPP derecho ipsilateral a la lesión de SNc mostró diferencias significativas entre los grupos experimentales (F=3,93;p<0,01), con un aumento significativo de esta variable en el grupo 2. Conclusiones. Estos resultados apuntan hacia una modificación de la actividad colinérgica posterior a la denervación de la SNc por inyección de 6-OHDA. Los cambios en las poblaciones de receptores muscarínicos distribuidos en SNc y NPP pueden ser parte de distintos mecanismos compensatorios que intentan atenuar el desequilibrio entre las transmisiones dopaminérgica y colinérgica, que se instala después de la degeneración de la vía negroestriatal. La lesión excitotóxica de lNST impone un nuevo mecanismo de ajuste a las células del NPP, que pudiera expresarse en los cambios en las poblaciones de receptores colinérgicos de la SNc (AU)

Introduction. Several studies that has focused to the dopaminergic transmission in the basal ganglia in parkinsonian condition, but only a few article has taking into account the imbalance between dopaminergic and cholinergic transmission. Objective. To evaluate the muscarinic cholinergic receptors density in SNc and PPN in the 6-OHDA model. Materials and methods. Were organized five experimental groups in correspondence to the place of the lesion: I. Non treated rats, II. 6-OHDA lesion in SNc, III. 6-OHDA lesion in SNc + quinolinic acid lesion in NST, IV. Sham operated rats, V. Quinolinic acid in STN. Were obtained coronal sections of 20 µm thickness of SNc and PPN from rats and in these sections was evaluated the muscarinic receptors density through autoradiographic technique with [3H]quinuclidinylbenzilate (QNB) (1.23 nM). The muscarinic antagonist atropine (1 µM) was utilized as non-specific union. The density was evaluated in both hemispheres and the density optical was converted in fentomolas/mg of tissue with base to values obtained from tritium standards. Results. Significant diminution of the muscarinic receptors density was found in the SNc ipsilateral to the 6-OHDA lesion from experimental groups II (t = 2.76; p < 0.05) and III (t = 4.06; p < 0.05). In the group V, was seen a significant increase of muscarinic receptor density in the SNc ipsilateral to the 6-OHDA lesion. The comparison between experimental groups evidenced significant differences among them (F = 13.13; p < 0.001) with a significant decrease in the density from SNc of groups II and III and significant increase in the density from SNc of group V in comparison of the others groups. In relation to PPN, muscarinic receptors density from right PPN ipsilateral to the 6-OHDA lesion, shown significant differences (F = 3.93; p < 0.01) between the experimental groups with a significant increase of this variable in the group II. Conclusions. These results signal a modification of cholinergic activity after 6-OHDA lesion. The changes in the muscarinic receptors populations located in SNc and PPN could be part of different compensatory mechanisms to attempt ameliorate the imbalance between dopaminergic and cholinergic transmission that it was installed after denervation of nigrostriatal forebrain bundle. The excitotoxic lesion of STN impose a new adjust mechanism for cell from PPN, which could be expressed in the changes of muscarinic cholinergic receptors population at the level of SNc (AU)

The amygdala is part of the behavioural reinforcement system modulating long-term potentiation in rat hippocampus.

Long-term potentiation (LTP) in the dentate gyrus can be modulated and prolonged by emotional/motivational influences when concurrently activated. A similar effect on LTP can be obtained by stimulating the amygdala, suggesting that this limbic structure might be part of the neural system involved in behavioural reinforcement. To confirm this we have performed a series of experiments in which the basolateral amygdala was either temporary inactivated by injection of lidocaine or permanently lesioned electrolytically. Both manipulations completely blocked the reinforcing effect of a motivational stimulus (drinking after 24-h deprivation) on LTP at the perforant pathway-dentate gyrus synapses, whilst leaving intact the non-reinforced potentiation. These results demonstrate that the basolateral amygdala is a key structure within the system involved in the modulatory interaction between the affective status of the animal and the mechanisms of functional plasticity.

[Effects of simultaneous transplant of foetal mesencephalic cells in the striatum and the subthalamic nucleus of hemiparkinsonian rats]. / Efectos del trasplante simultáneo de células mesencefálicas fetales en el estriado y el núcleo subtalámico de ratas hemiparkinsonianas.

INTRODUCTION: The main strategy followed in neural transplants as a method of treatment for Parkinson s disease, both experimental and clinical, has been to introduce foetal mesencephalic cells into the target area: the striatum. However, when the dopaminergic cells in the substantia nigra degenerate, not only is the dopaminergic innervation of the striatum affected but also other nuclei: globus pallidus, substantia nigra, substantia nigra pars reticulata and subthalamic nucleus. A series of data from pharmacological and physiological studies offer strong evidence that the dopamine released in these nuclei may play an important role in regulating the output nuclei of the basal ganglia. AIM: To evaluate the effect of transplanting foetal mesencephalic cells on the behaviour of 6 OH DA rats when introduced into the striatum and the subthalamic nucleus. MATERIALS AND METHODS: 6 OH DA was used to induce lesions in the substantia nigra of rats, which were divided into several experimental groups. The rotating activity induced by D amphetamine (5 mg/kg, intraperitoneally) and apomorphine (0.05 mg/kg, subcutaneously) was evaluated before and three months after the transplant in all the experimental groups, except in the control group of healthy rats. The hemiparkinsonian rats received a total of 350,000 foetal ventral mesencephalic cells, which were implanted within small deposits in the striatum (8) and in the subthalamic nucleus (4). RESULTS AND CONCLUSIONS: Rotation induced by both drugs was significantly lower (p= 0.05) in animals that had had dopaminergic cells transplanted into the striatum body. No significant improvement in this behaviour was to be found when transplants were limited to just the subthalamus or, simultaneously, also to the striatum. A significant increase in rotating behaviour induced by apomorphine was observed in the group which received a transplant in just the subthalamus.

Efectos del trasplante simultáneo de células mesencefálicas fetales en el estriado y el núcleo subtalámico de ratas hemiparkinsonianas / Effects of simultaneous transplant of foetal mesencephalic cells in the striatum and the subthalamic nucleus of hemiparkinsonian rats

Introducción. La principal estrategia de trasplante neural como tratamiento de la enfermedad de Parkinson, tanto experimental como clínico, ha sido colocar las células mesencefálicas fetales en su principal blanco: el estriado. Sin embargo, cuando las células dopaminérgicas de la sustancia negra degeneran, no sólo se afecta la inervación dopaminérgica del estriado; por el contrario, la inervación de otros núcleos, como el globo pálido, sustancia negra parte reticulada y núcleo subtalámico, también se afectan. Una serie de datos provenientes de estudios farmacológicos y fisiológicos proveen de fuertes evidencias acerca de que la dopamina liberada en estos núcleos puede desempeñar un papel importante en la regulación de los núcleos de salida de los ganglios basales. Objetivo. El objetivo principal de este estudio fue evaluar el efecto del trasplante de células mesencefálicas fetales sobre la conducta de ratas-6-OH-DA, cuando el mismo se coloca en el estriado y el núcleo subtalámico. Materiales y métodos. Se utilizaron ratas con lesión de la sustancia negra inducida por la 6-OHDA, divididas en varios grupos experimentales. La actividad rotatoria inducida por D-anfetamina (5 mg/kg, intraperitonealmente) y apomorfina (0,05 mg/kg, subcutáneamente) se evaluó antes y en los tres meses posteriores al trasplante en todos los grupos experimentales, excepto en el grupo de controles sanos. Las ratas hemiparkinsonianas recibieron un total de 350.000 células de mesencéfalo ventral fetal, que se implantaron en pequeños depósitos en el estriado (8) y en el núcleo subtalámico (4). Resultados y conclusiones. Los animales con trasplante de células dopaminérgicas en el cuerpo estriado redujeron significativamente el número de vueltas inducido por ambas drogas (p= 0,05). No fue posible demostrar mejoría significativa de estas conductas cuando los trasplantes se colocaron sólo en el subtálamo o en este núcleo, simultáneamente al estriado. Se observó un incremento significativo en la conducta de giro inducida por apomorfina en el grupo con trasplante aislado en subtálamo (AU)

Efectos del trasplante simultáneo de células mesencefálicas fetales en el estriado y el núcleo subtalámico de ratas hemiparkinsonianas / EFFECTS OF SIMULTANEOUS TRANSPLANT OF FOETAL MESENCEPHALIC CELLS IN THE STRIATUM AND THE SUBTHALAMIC NUCLEUS OF HEMIPARKINSONIAN RATS

Introducción. La principal estrategia de trasplante neural como tratamiento de la enfermedad de Parkinson, tanto experimental como clínico, ha sido colocar las células mesencefálicas fetales en su principal blanco: el estriado. Sin embargo, cuando las células dopaminérgicas de la sustancia negra degeneran, no sólo se afecta la inervación dopaminérgica del estriado; por el contrario, la inervación de otros núcleos, como el globo pálido, sustancia negra parte reticulada y núcleo subtalámico, también se afectan. Una serie de datos provenientes de estudios farmacológicos y fisiológicos proveen de fuertes evidencias acerca de que la dopamina liberada en estos núcleos puede desempeñar un papel importante en la regulación de los núcleos de salida de los ganglios basales. Objetivo. El objetivo principal de este estudio fue evaluar el efecto del trasplante de células mesencefálicas fetales sobre la conducta de ratas-6-OH-DA, cuando el mismo se coloca en el estriado y el núcleo subtalámico. Materiales y métodos. Se utilizaron ratas con lesión de la sustancia negra inducida por la 6-OHDA,divididas en varios grupos experimentales. La actividad rotatoria inducida por D-anfetamina (5 mg/kg, intraperitonealmente) y apomorfina (0,05 mg/kg, subcutáneamente) se evaluó antes y en los tres meses posteriores al trasplante en todos los grupos experimentales, excepto en el grupo de controles sanos. Las ratas hemiparkinsonianas recibieron un total de 350.000 células de mesencéfalo ventral fetal, que se implantaron en pequeños depósitos en el estriado (8) y en el núcleo subtalámico (4). Resultados y conclusiones. Los animales con trasplante de células dopaminérgicas en el cuerpo estriado redujeron significativamente el número de vueltas inducido por ambas drogas (p=0,05). No fue posible demostrar mejoría significativa de estas conductas cuando los trasplantes se colocaron sólo en el subtálamo o en este núcleo, simultáneamente al estriado. Se observó un incremento significativo en la conducta de giro inducida por apomorfina en el grupo con trasplante aislado en subtálamo neural(AU)

[Nerve growth factor: possibilities and limitations of its clinical application]. / Factor de crecimiento nervioso: posibilidades y limitaciones de su aplicación clínica.

INTRODUCTION: The use of neurotrophic factors for the treatment of degenerative disorders of the nervous system opens up promising new perspectives. DEVELOPMENT: Nerve growth factor (NGF) represents the most known and studied trophic factor, which acts on sensory and sympathetic neurons of the peripheral nervous system, and on basal forebrain and striatal cholinergic neurons of the central nervous system. The specificity and trophic actions of NGF on these neuronal populations and its efficacy at preventing neurodegeneration have led to its proposal of evaluation in the treatment of neurological diseases such as: Alzheimer's disease, diabetic neuropathies and Huntington's diseases. Preclinical and clinical studies carried out in animal models and patients with diagnosis of these diseases have revealed satisfactory results. The difficulties of the NGF central chronic infusion, and the NGF detrimental effects arising from the stimulation of other sensitive neuronal population have stimulated active efforts for the development of more efficacious delivery strategies. Besides, it has also promoted further studies on the relation between the neuropathological stage, the dose and the effects of NGF administration. CONCLUSION: The NGF is a potential therapeutic agent in the treatment of neurodegenerative diseases.

Factor de crecimiento nervioso: posibilidades y limitaciones de su aplicación clínica / Nerve growth factor

Introducción. El uso de factores neurológicos en el tratamiento de las enfermedades degenerativas del sistema nervioso abre nuevas y prometedoras perspectivas. Desarrollo. El factor de crecimiento nervioso (NGF) representa el factor trófico mejor conocido y estudiado, actuando sobre las neuronas sensitivas y simpáticas del sistema nervioso periférico y sobre el cerebro basal frontal y neuronas colinérgicas estriadas del sistema nervioso central. La especificidad y acciones tróficas del NGF sobre estas poblaciones neuronales y su eficacia en prevenir la neurodegeneración han conducido a la propuesta de valorar su uso en el tratamiento de enfermedades neurológicas tales como la enfermedad de Alzheimer, la neuropatía diabética y la enfermedad de Huntington. Estudios preclínicos y clínicos llevados a cabo en modelos animales y en enfermos con diagnósticos de estas enfermedades han puesto de manifiesto resultados satisfactorios. Las dificultades para la infusión central de NGF originados por la estimulación de otras poblaciones neuronales sensibles han estimulado la iniciativa para desarrollar estrategias de entrega más eficaces. Además, esto ha dado lugar a otros estudios sobre la relación entre la etapa neuropatológica, la dosis y los efectos de la administración de NGF. Conclusión. El NGF es un agente terapéutico potencial en el tratamiento de las enfermedades neurodegerativas(AU)

[Nerve growth factor and diabetic neuropathy]. / Factor de crecimiento nervioso y neuropatía diabética.

INTRODUCTION: The progress made by contemporary neurobiology opens new horizons both for study and for treatment of disorders of the nervous system. At the present time we are in the age of growth factors. These are molecules which affect survival, development and the normal functioning of cell populations. DEVELOPMENT: One of the most widely studied growth factors is nervous growth factor (NGF) which is necessary for normal life of various types of neurones, including sensory nerves and nerves derived from the neural crests. Diabetic neuropathy, worldwide a major neurological disorder, is primarily characterized by involvement of the fine fibres for temperature and pain perception and also by a variety of autonomic disorders. The great dependence of sensory and sympathetic nerves on NGF, the quantity of results which show alterations in the levels of neurotrophic factors in diabetic neuropathy (DN), and the encouraging experimental and clinical results of using NGF as a new alternative to treatment with DN, were the basic reasons which led us to do this study. CONCLUSIONS: We started by considering neurotrophic factors, especially NGF and its connection with DN disorders and its clinical applications, we made a summary of the main findings in this field to date.

Factor de crecimiento nervioso y neuropatía diabética / Nerve growth factor and diabetic neuropathy

Introducción. El desarrollo alcanzado por la neurobiología contemporánea abrió nuevos horizontes tanto para el estudio como para el tratamiento de afecciones del sistema nervioso. En el presente, nos encontramos inmersos en la era de los factores de crecimiento, moléculas cuyo efecto modula fenómenos como la supervivencia, el desarrollo y el funcionamiento normal de poblaciones celulares. Desarrollo. Entre los factores de crecimiento más ampliamente estudiados se puede señalar el factor de crecimiento nervioso (NGF), compuesto necesario para la vida normal de variados tipos neuronales, entre los que se puede mencionar las neuronas sensoriales y simpáticas derivadas de las crestas neurales. La neuropatía diabética, afección neurológica de elevada incidencia a nivel mundial, se caracteriza primariamente por la afección de fibras finas encargadas de la percepción térmica y dolorosa, así como por variadas disfunciones autonómicas. La elevada dependencia de las neuronas sensoriales y simpáticas por el NGF, el cúmulo de resultados que evidencian alteraciones en los niveles del factor neurotrófico en la neuropatía diabética (ND), así como los alentadores resultados experimentales y también clínicos del empleo del NGF como novedosa alternativa en el tratamiento de la ND, constituyen los puntos de partida fundamentales para la realización del presente trabajo. Conclusiones. Comenzando por abundar sobre factores neurotróficos y en especial sobre el NGF, argumentando su vínculo con las afecciones que tienen lugar en la ND y llegando hasta sus aplicaciones clínicas, pretendemos exponer de forma resumida los principales hallazgos que existen sobre la temática en cuestión hasta el presente (AU)