Methamphetamine abuse impairs motor cortical plasticity and function.

Exposure to addictive drugs triggers synaptic plasticity in reward-related brain regions, such as the midbrain, nucleus accumbens and the prefrontal cortex. Effects of chronic drug exposure on other brain areas have not been fully investigated. Here, we characterize synaptic plasticity in motor cortex after methamphetamine self-administration in rats. We show that this causes a loss of corticostriatal plasticity in rat brain slices and impaired motor learning in the rotarod task. These findings are paralleled by the observation of a lack of transcranial magnetic stimulation-induced potentiation or depression of motor evoked potentials in human patients with addiction, along with poor performance in rotary pursuit task. Taken together, our results suggest that chronic methamphetamine use can affect behavioral performance via drug-evoked synaptic plasticity occluding physiological motor learning.

Vagus nerve stimulation in treating depression: A tale of two stories.

Vagus nerve stimulation (VNS) has been widely used to treat different neurological disorders, especially epilepsy. Accumulating evidence also suggests its potential application in antidepressive therapy, given that VNS has been confirmed by several clinical trials to exert long-term effects on mitigating depression and reducing the risk of relapse in depressed patients. Likewise, VNS has also proven to ameliorate the behavioral deficits in a rat model of depression. While the influences of VNS on monoamine metabolism and mood improvement are well-recognized, the underlying mechanisms mediating its antidepressive action remain poorly understood. Recent findings suggest that VNS-enhanced proliferation of hippocampal neural progenitor cells (NPCs) and synaptic transmission might serve as a monoamine-independent pathway contributive to the beneficial effects of VNS on depression. Here we briefly reviewed the recent progress in this field, based on which we propose that there might be, at least, two little-overlapped, and yet interactive pathways mediating the antidepressive action of VNS.

Retracted: Hypocretin (orexin) cell transplantation diminishes narcoleptic-like sleep behavior in rats.

Arias-Carrión, O.; Drucker-Colín, R.; Murillo-Rodríguez, E. "Hypocretin (orexin) cell transplantation diminishes narcoleptic-like sleep behavior in rats." CNS Neurol. Disord. Drug Targets, 2011,11(7). The above-cited paper has been retracted from CNS & Neurological Disorders-Drug Targets at the request of the authors. The authors advised the Journal of their intention to perform additional experiments in order to strengthen their initial results, at which time an amended manuscript may be submitted.

Ser estudiante de medicina / Being Medical Student

No disponible

Terapia celular para el tratamiento de la enfermedad de Parkinson / No dispoible

En la enfermedad de Parkinson, las neuronas dopaminérgicas de lasustancia nigra degeneran, lo que trae como consecuencia un défi cit dedopamina en sus áreas de proyección. Estas alteraciones histológicasy neuroquímicas se traducen en la mayoría de los trastornos motoresque presentan los pacientes parkinsonianos. Las estrategias terapéuticasactuales se basan en fármacos que mejoran la neurotransmisióndopaminergica. Este enfoque terapéutico tiene efectos secundarios alargo plazo, como fl uctuaciones de la respuesta motora y discinesias. Eltrasplante de células dopaminérgicas fetales ha demostrado una mejoríade los síntomas clínicos. Actualmente, se desarrollan nuevas estrategiasterapéuticas para estimular un reemplazo neuronal endógeno a partirde precursores neuronales presentes en el cerebro adulto. Este trabajoresume los estudios que muestran el potencial de la terapia celular enla enfermedad de Parkinson(AU)

The pathological hallmark of Parkinson’s disease is a gradual loss ofnigrostriatal dopamine-containing neurons, which is responsible for thecardinal motor symptoms of the disease. Current therapeutic strategiesare mostly based on pharmacological enhancement of dopaminergicneurotransmission. This therapeutic approach has several long-term sideeffects, such as dyskinesias and fl uctuations of response, and is thereforelimited in its use. Transplantation of fetal dopaminergic precursor cellshas provided the proof that a cell replacement therapy can ameliorateclinical symptoms in affected patients. Novel therapies aiming at astimulation of an endogenous dopamine production within the brain ata continuous rate might provide a more physiological and elegant wayto overcome the dopaminergic defi ciency in parkinsonian brains. Thisarticle will review recent studies demonstrating the potential of thesealternative cell graft sources for treating Parkinson’s disease(AU)

Terapia celular para el tratamiento de la enfermedad de Parkinson / Cell therapy to treat Parkinson’s disease

En la enfermedad de Parkinson, las neuronas dopaminérgicas de la sustancia nigra degeneran, lo que trae como consecuencia un déficit de dopamina en sus áreas de proyección. Estas alteraciones histológicasy neuroquímicas se traducen en la mayoría de los trastornos motores que presentan los pacientes parkinsonianos. Las estrategias terapéuticasactuales se basan en fármacos que mejoran la neurotransmisión dopaminergica. Este enfoque terapéutico tiene efectos secundarios a largo plazo, como fl uctuaciones de la respuesta motora y discinesias. Eltrasplante de células dopaminérgicas fetales ha demostrado una mejoría de los síntomas clínicos. Actualmente, se desarrollan nuevas estrategiasterapéuticas para estimular un reemplazo neuronal endógeno a partir de precursores neuronales presentes en el cerebro adulto. Este trabajo resume los estudios que muestran el potencial de la terapia celular enla enfermedad de Parkinson

The pathological hallmark of Parkinson’s disease is a gradual loss of nigrostriatal dopamine-containing neurons, which is responsible for thecardinal motor symptoms of the disease. Current therapeutic strategies are mostly based on pharmacological enhancement of dopaminergicneurotransmission. This therapeutic approach has several long-term side effects, such as dyskinesias and fl uctuations of response, and is thereforelimited in its use. Transplantation of fetal dopaminergic precursor cells has provided the proof that a cell replacement therapy can ameliorate clinical symptoms in affected patients. Novel therapies aiming at a stimulation of an endogenous dopamine production within the brain at a continuous rate might provide a more physiological and elegant way to overcome the dopaminergic defi ciency in parkinsonian brains. Thisarticle will review recent studies demonstrating the potential of these alternative cell graft sources for treating Parkinson’s disease (AU)

[Neurogenesis as a therapeutic strategy to regenerate central nervous system]. / Neurogénesis como estrategia terapéutica para regenerar el sistema nervioso central.

INTRODUCTION: In the past few years, it has been demonstrated that the adult mammalian brain maintains the capacity to generate new neurons from neural stem/progenitor cells. These new neurons integrate into pre-existing systems through a process referred to as 'neurogenesis in the adult brain'. DEVELOPMENT: This discovery has modified our understanding of how the central nervous system functions in health and disease. Until today, a great effort has been made attempting to decipher the mechanisms regulating adult neurogenesis, which might help to induce neuronal endogenous cell replacement in various neurological diseases. CONCLUSIONS: In this revision, we will attempt to shed some light on the neurogenesis process with respect to diseases of the central nervous system and we will describe some therapeutic potentials in relation to neurodegenerative diseases.

Neurogénesis como estrategia terapéutica para regenerar el sistema nervioso central / Neurogenesis as a therapeutic strategy to regenerate central nervous system

La investigación generada en los últimos años ha demostrado que el cerebro adulto de mamíferosmantiene la capacidad de generar nuevas neuronas a partir de células troncales/progenitoras neuronales. Las nuevas neuronas se integran a las redes preexistentes a través de un proceso denominado ‘neurogénesis en el cerebro adulto’. Desarrollo.Este descubrimiento ha modificado nuestra comprensión de cómo el sistema nervioso central funciona en la salud y en la enfermedad. Hasta ahora se ha realizado un gran esfuerzo para descifrar los mecanismos que regulan la neurogénesis en el adulto, lo cual puede permitir realizar un reemplazo neuronal endógeno en diversos trastornos neurológicos. Conclusiones.Esta revisión se centra en la neurogénesis que se presenta en respuesta a trastornos del sistema nervioso central y aborda su potencial terapéutico en las enfermedades neurodegenerativas

In the past few years, it has been demonstrated that the adult mammalian brain maintains the capacityto generate new neurons from neural stem/progenitor cells. These new neurons integrate into pre-existing systems through a process referred to as ‘neurogenesis in the adult brain’. Development. This discovery has modified our understanding of how the central nervous system functions in health and disease. Until today, a great effort has been made attempting to decipher themechanisms regulating adult neurogenesis, which might help to induce neuronal endogenous cell replacement in various neurological diseases. Conclusions. In this revision, we will attempt to shed some light on the neurogenesis process with respect to diseases of the central nervous system and we will describe some therapeutic potentials in relation to neurodegenerativediseases

[Neurogenesis in the adult brain]. / Neurogénesis en el cerebro adulto.

INTRODUCTION: The discovery that new neurons continue to be generated in the adult brain has modified the concept of brain plasticity and has brought to light new mechanisms that ensure the homeostasis of the nervous system. DEVELOPMENT: Neurogenesis, that is to say, the process involving the generation of new neurons, has been shown to occur in the hippocampus and in the olfactory bulb in adult mammals, which suggests that neuronal stem cells persist throughout the entire lifespan. The primary precursors have been identified in specialised regions called neurogenic niches. Interestingly, the cells that give rise to the new neurons in the adult brain express markers for glial cells, a cell lineage that is a long way from that of neurons. Studies conducted during the development of the brain have shown that radial glial cells not only give rise to astrocytes but also neurons, oligodendrocytes and ependymal cells. In addition, it is known that radial glial cells are also the precursors of neuronal stem cells in the adult brain. CONCLUSIONS: Overall, these data support the idea that stem cells develop from a neuroepithelial-glial radial-astrocytic lineage. Thus, identifying the primary precursors, both in the developing brain and in the adult brain, is essential to understand the functioning of the nervous system and, from there, to develop strategies for neuronal replacement in the adult brain when needed.

Neurogénesis en el cerebro adulto / Neurogenesis in the adult brain

Introducción. El descubrimiento de que nuevas neuronas continúan generándose en el cerebro adulto ha modificado el concepto de plasticidad cerebral y ha revelado nuevos mecanismos que garantizan la homeostasis del sistema nervioso. Desarrollo. La neurogénesis, proceso que involucra la generación de nuevas neuronas, se ha demostrado en el hipocampo y en el bulbo olfatorio de mamíferos adultos, lo cual sugiere la persistencia de células troncales neuronales a lo largo de toda la vida. Los precursores primarios se han identificado en zonas especializadas denominadas nichos neurogénicos. De manera interesante, la célula que da origen a las nuevas neuronas en el cerebro adulto expresa marcadores de células gliales, un linaje celular lejano al de las neuronas. Trabajos realizados durante el desarrollo del cerebro han demostrado que la glía radial no sólo origina astrocitos, sino también neuronas, oligodendrocitos y células ependimales. Además, se sabe que la glía radial también es la precursora de las células troncales neuronales del cerebro adulto. Conclusiones. En conjunto, estos datos soportan la idea de que las células troncales se desarrollan de un linaje neuroepitelial-glía radial-astrocítico. Así, la identificación de los precursores primarios, tanto en el cerebro en desarrollo como en el cerebro adulto, es fundamental para comprender el funcionamiento del sistema nervioso y, con esto, desarrollar estrategias de reemplazo neuronal en el cerebro adulto que lo requiera

Introduction. The discovery that new neurons continue to be generated in the adult brain has modified the concept of brain plasticity and has brought to light new mechanisms that ensure the homeostasis of the nervous system. Development. Neurogenesis, that is to say, the process involving the generation of new neurons, has been shown to occur in the hippocampus and in the olfactory bulb in adult mammals, which suggests that neuronal stem cells persist throughout the entire lifespan. The primary precursors have been identified in specialised regions called neurogenic niches. Interestingly, the cells that give rise to the new neurons in the adult brain express markers for glial cells, a cell lineage that is a long way from that of neurons. Studies conducted during the development of the brain have shown that radial glial cells not only give rise to astrocytes but also neurons, oligodendrocytes and ependymal cells. In addition, it is known that radial glial cells are also the precursors of neuronal stem cells in the adult brain. Conclusions. Overall, these data support the idea that stem cells develop from a neuroepithelial- glial radial-astrocytic lineage. Thus, identifying the primary precursors, both in the developing brain and in the adult brain, is essential to understand the functioning of the nervous system and, from there, to develop strategies for neuronal replacement in the adult brain when needed

Neurogenesis in the subventricular zone following transcranial magnetic field stimulation and nigrostriatal lesions.

Neurogenesis continues at least in two regions of the mammalian adult brain, the subventricular zone (SVZ) and the subgranular zone in hippocampal dentate gyrus. Neurogenesis in these regions is subjected to physiological regulation and can be modified by pharmacological and pathological events. Here we report the induction of neurogenesis in the SVZ and the differentiation after nigrostriatal pathway lesion along with transcranial magnetic field stimulation (TMFS) in adult rats. Significant numbers of proliferating cells demonstrated by bromodeoxyuridine-positive reaction colocalized with the neuronal marker NeuN were detected bilaterally in the SVZ, and several of these cells also expressed tyrosine hydroxylase. Transplanted chromaffin cells into lesioned animals also induced bilateral appearance of subependymal cells. These results show for the first time that unilateral lesion, transplant, and/or TMFS induce neurogenesis in the SVZ of rats and also that TMFS prevents the motor alterations induced by the lesion.