Search results for "PLASTICITY"
showing 10 items of 765 documents
Endocannabinoid Role in Synaptic Plasticity and Learning
2009
Endocannabinoids have recently emerged as versatile modulators of synaptic transmission and can act as retrograde neurotransmitters. As they cannot be stored in synaptic vesicles, endocannabinoid signaling is believed to start ‘on-demand,’ via a stimulus-dependent synthesis from membranous precursors at the postsynaptic site. After synthesis, endocannabinoids bind presynaptically to cannabinoid type 1 (CB1) receptors, leading to a short- or long-term suppression of neurotransmitter release. CB1 receptors are present in a plethora of different synaptic connections in the brain. Electrophysiological and behavioral analyses of mutant mice lacking CB1 receptors and of pharmacologically treated …
Chapter 31 Transcranial magnetic stimulation studies of contralesional space attention deficits
2002
Publisher Summary The power of transcranial magnetic stimulation (TMS) to disrupt and modulate the neural activity in focal brain regions has provided researchers in this field a promising tool to empirically test specific neuropsychological models and constructs of contralesional space attention deficits. A group of studies has used TMS to transiently disrupt the cortical activity of the focal brain areas in normal subjects to replicate the effects of neurological lesions. This chapter discusses a number of studies, using single-pulse, paired-TMS, and repetitive TMS (rTMS) and different experimental paradigms that show how this technique can be of fundamental importance, in elucidating the…
Continuous neuronal integration in the cerebral cortex of rodents and humans
2021
La plasticidad neuronal es la capacidad del sistema nervioso para realizar cambios funcionales adaptativos, durante el desarrollo y la edad adulta. Se refiere a todo tipo de cambios que modifican la forma y estructura de las neuronas y de las células gliales del sistema nervioso central (SNC). Entre los diferentes niveles de plasticidad que ocurren en el cerebro adulto, la neurogénesis es un tipo de plasticidad cerebral, que implica la producción e incorporación continua de nuevas neuronas en las redes neuronales funcionales. En el cerebro de los mamíferos adultos, las nuevas neuronas se generan tradicionalmente en dos "nichos neurogénicos canónicos": la zona subventricular (SVZ) y la zona …
Nicotinic receptor agonists as neuroprotective/neurotrophic drugs. Progress in molecular mechanisms
2007
In the present work we reviewed recent advances concerning neuroprotective/neurotrophic effects of acute or chronic nicotine exposure, and the signalling pathways mediating these effects, including mechanisms implicated in nicotine addiction and nAChR desensitization. Experimental and clinical data largely indicate long-lasting effects of nicotine and nicotinic agonists that imply a neuroprotective/neurotrophic role of nAChR activation, involving mainly alpha 7 and alpha 4 beta 2 nAChR subtypes, as evidenced using selective nAChR agonists. Compounds interacting with neuronal nAChRs have the potential to be neuroprotective and treatment with nAChR agonists elicits long-lasting neurotrophic e…
Analysis of structural plasticity in the adult and adolescent mouse brain. Effects of erythropoietin
2019
INTRODUCCIÓN Los organismos están sujetos diariamente a cambios que ocurren en su entorno y dentro del propio organismo. Estas entradas de información del medio externo e interno son integradas y analizadas por el organismo con el fin de dar una respuesta adecuada que asegure la supervivencia. Es crucial, por lo tanto, que el sistema responda de forma apropiada al amplio abanico de cambios y demandas que acontecen a lo largo de la vida del organismo. En este aspecto, el sistema nervioso se destaca como uno de los principales sistemas encargados de mantener el orden interno y reaccionar con cambios adaptativos a los eventos que lo rodean. Un funcionamiento aberrante del sistema da lugar a la…
Impact of pharmacological and environmental manipulations on neuronal structural plasticity and dynamics
2017
El sistema nervioso de vertebrados es uno de los más estudiados, aunque peor comprendidos, del organismo de mamíferos. Desde que Ramón y Cajal postuló su teoría celular de este sistema (Ramón y Cajal 1909), la neurona se ha postulado como su unidad funcional. Sin embargo, durante las últimas décadas se ha revolucionado la visión que se tenía de éste. Una de las percepciones más asentadas era que, tras el desarrollo embrionario, el sistema nervioso se mantenía inmutable. Sin embargo, ahora sabemos que diferentes formas de plasticidad gobiernan su adaptación, que son necesarias para importantes procesos del día a día, tales como el aprendizaje y la memoria (Smythies 2002; Berlucchi and Buchte…
Modulation of Human Motor Cortical Excitability and Plasticity by Opuntia Ficus Indica Fruit Consumption: Evidence from a Preliminary Study through N…
2022
Indicaxanthin (IX) from Opuntia Ficus Indica (OFI) has been shown to exert numerous biological effects both in vitro and in vivo, such as antioxidant, anti-inflammatory, neuro-modulatory activity in rodent models. Our goal was to investigate the eventual neuro-active role of orally assumed fruits containing high levels of IX at nutritionally-relevant amounts in healthy subjects, exploring cortical excitability and plasticity in the human motor cortex (M1). To this purpose, we applied paired-pulse transcranial magnetic stimulation and anodal transcranial direct current stimulation (a-tDCS) in basal conditions and followed the consumption of yellow cactus pear fruits containing IX or white ca…
Parietal Cortex Connectivity as a Marker of Shift in Spatial Attention Following Continuous Theta Burst Stimulation
2021
Non-invasive brain stimulation is a useful tool to probe brain function and provide therapeutic treatments in disease. When applied to the right posterior parietal cortex (PPC) of healthy participants, it is possible to temporarily shift spatial attention and mimic symptoms of spatial neglect. However, the field of brain stimulation is plagued by issues of high response variability. The aim of this study was to investigate baseline functional connectivity as a predictor of response to an inhibitory brain stimulation paradigm applied to the right PPC. In fourteen healthy adults (9 female, aged 24.8 ± 4.0 years) we applied continuous theta burst stimulation (cTBS) to suppress activity in the …
The corticotrophin-releasing factor/urocortin system regulates white fat browning in mice through paracrine mechanisms.
2015
Objectives:\ud The corticotrophin-releasing factor (CRF)/urocortin system is expressed in the adipose tissue of mammals, but its functional role in this tissue remains unknown.\ud \ud Methods:\ud Pharmacological manipulation of the activity of CRF receptors, CRF1 and CRF2, was performed in 3T3L1 white pre-adipocytes and T37i brown pre-adipocytes during in vitro differentiation. The expression of genes of the CRF/urocortin system and of markers of white and brown adipocytes was evaluated along with mitochondrial biogenesis and cellular oxygen consumption. Metabolic evaluation of corticosterone-deficient or supplemented Crhr1-null (Crhr1−/−) mice and their wild-type controls was performed alo…
Toward a link between brain plasticity and satiety
2021
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