Epigenetics in the nervous system: An overview of its essential role.

The role that epigenetic mechanisms play in phenomena such as cellular differentiation during embryonic development, X chromosome inactivation, and cancers is well‑characterized. Epigenetic mechanisms have been implicated to be the mediators of several functions in the nervous system such as in neuronal‑glial differentiation, adult neurogenesis, the modulation of neural behavior and neural plasticity, and also in higher brain functions like cognition and memory. Its particular role in explaining the importance of early life/ social experiences on adult behavioral patterns has caught the attention of scientists and has spawned the exciting new field of behavioral epigenetics which may hold the key to explaining many complex behavioral paradigms. Epigenetic deregulation is known to be central in the etiology of several neuropsychiatric disorders which underscore the importance of understanding these mechanisms more thoroughly to elucidate novel and effective therapeutic approaches. In this review we present an overview of the findings which point to the essential role played by epigenetics in the vertebrate nervous system.

Neuroplasticidad en psiguiatría: algunos aspectos de utilidad teórica y práctica / Neuroplsticity in psychiatry: some aspects of theoretical and practical usefulness

La neuroplasticidad es la capacidad que tiene el sistema nervioso de experimentar cambios funcionales y estructurales como respuesta a las variaciones que se producen en el ambiente interno y externo. Las características de este fenómeno se van develando a pasos agigantados gracias a los avances vertiginosos de la neurociencia en los últimos años. Sus alcances prometen ser alentadores para comprender la intimidad de las condiciones normales y patológicas con sede en el sistema nervioso central y, por lo tanto, para establecer estrategias preventivas y terapéuticas especialmente en el área de la Neurología y la Psiquiatría.Este trabajo presenta una revisión de los conocimientos publicados hasta mediados de 2009 en relación a diversos aspectos teóricos y prácticos de la neuroplasticidad relacionados con la Psiquiatría: estrés, influencias genéticas y ambientales, potencialidades terapéuticas farmacológicas y psicoterapéuticas. A partir de aquí se pretende mostrar cómo el aporte de la neurociencia ha profundizado la comprensión de varios procesos mentales, sus bases biológicas y la importancia de las intrincadas influencias ambientales y genéticas en el desarrollo de diversos fenómenos psicopatológicos. Las magníficas potencialidades preventivas y terapéuticas relacionadas con la neuroplasticidad hacen que sea necesaria una actualización permanente de estos conocimientos.

Neuroplasticity is the ability of the nervous system to experience functional and structural changes in response to the variations taking place in the internal and the external environment. The characteristics of this phenomenon are being revealed at great speed, thanks to the dramatic advances in neuroscience over the last years. Their scope promise to be encouraging to understand the intimacy of normal and pathological conditions stemming from the central nervous system, and therefore, to establish preventive and therapeutical strategies en the field of Neurology and Psychiatry. This work provide a review of the information published until the mid 90's on certain theoretical and practical aspects of neuroplasticity related with Psychiatry: stress, genetic and environmental influences, therapeutic, pharmacological and psychotherapeutic potential. From this point, the aim is to demonstrate how the neuroscientific contribution has deepened the understanding of several mental processes, its biological foundations and the importance of the intricate environmental and genetic influences for the development of different psychopathological phenomena. The astonishing preventive and therapeutic potential associated with neuroplasticity make it necessary to continuously update this knowledge.

Cyclic AMP response element binding protein and brain-derived neurotrophic factor: molecules that modulate our mood?

Depression is the major psychiatric ailment of our times, afflicting approximately 20% of the population. Despite its prevalence, the pathophysiology of this complex disorder is not well understood. In addition, although antidepressants have been in existence for the past several decades, the mechanisms that underlie their therapeutic effects remain elusive. Building evidence implicates a role for the plasticity of specific neuro-circuitry in both the pathophysiology and treatment of depression. Damage to limbic regions is thought to contribute to the etiology of depression and antidepressants have been reported to reverse such damage and promote adaptive plasticity. The molecular pathways that contribute to the damage associated with depression and antidepressant-mediated plasticity are a major focus of scientific enquiry. The transcription factor cyclic AMP response element binding protein (CREB) and the neurotrophin brain-derived neurotrophic factor (BDNF) are targets of diverse classes of antidepressants and are known to be regulated in animal models and in patients suffering from depression. Given their role in neuronal plasticity, CREB and BDNF have emerged as molecules that may play an important role in modulating mood. The purpose of this review is to discuss the role of CREB and BDNF in depression and as targets/mediators of antidepressant action.

Morphometric evidences for regional variation in potential of neural plasticity

RESUMEN: Aunque la plasticidad neural muestra la capacidad del sistema nervioso para cambiar su estructura y función, lo cual es un hecho bien documentado, pocos estudios han mostrado la variación regional, dentro de la estructura del sistema nervioso central para sufrir cambios plásticos. A través de disecciones parasagitales, secuenciadas de medial a lateral, se estudió el grosor de la capa molecular, en el límite de la cisura primaria de hemisferio izquierdo del cerebelo, de ratas, con el propósito de evaluar las diferencias regionales en plasticidad. A pesar de la homogeneidad de la histología cerebelar, el estudio mostró que hay una diferencia interlobular significativa entre el grosor de la capa molecular en el límite de la fisura prima. Agregado a ello, fue revelado que los cambios de grosor tienen una tendencia significativa dentro de cada límite. La heterogeneidad cuantitativa de la arquitectura cerebelar, tal como la variación en el grosor cortical, puede proveer algunas evidencias que muestran que regiones diferentes de un corte homogéneo, aún de límites y áreas adyacentes dentro del mismo, pueden tener diferentes potenciales para plasticidad.