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1.
Mol Cell ; 63(5): 796-810, 2016 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-27570075

RESUMEN

Stress granules (SGs) are ribonucleoprotein complexes induced by stress. They sequester mRNAs and disassemble when the stress subsides, allowing translation restoration. In amyotrophic lateral sclerosis (ALS), aberrant SGs cannot disassemble and therefore accumulate and are degraded by autophagy. However, the molecular events causing aberrant SG formation and the molecular players regulating this transition are largely unknown. We report that defective ribosomal products (DRiPs) accumulate in SGs and promote a transition into an aberrant state that renders SGs resistant to RNase. We show that only a minor fraction of aberrant SGs is targeted by autophagy, whereas the majority disassembles in a process that requires assistance by the HSPB8-BAG3-HSP70 chaperone complex. We further demonstrate that HSPB8-BAG3-HSP70 ensures the functionality of SGs and restores proteostasis by targeting DRiPs for degradation. We propose a system of chaperone-mediated SG surveillance, or granulostasis, which regulates SG composition and dynamics and thus may play an important role in ALS.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas Reguladoras de la Apoptosis/metabolismo , Autofagia/genética , Gránulos Citoplasmáticos/metabolismo , Proteínas HSP70 de Choque Térmico/metabolismo , Proteínas de Choque Térmico/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Ribosomas/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Reguladoras de la Apoptosis/genética , Arsenitos/farmacología , Gránulos Citoplasmáticos/química , Gránulos Citoplasmáticos/efectos de los fármacos , Expresión Génica , Proteínas HSP70 de Choque Térmico/genética , Células HeLa , Proteínas de Choque Térmico/genética , Homeostasis , Humanos , Leupeptinas/farmacología , Chaperonas Moleculares , Estrés Oxidativo , Inhibidores de Proteasoma/farmacología , Unión Proteica , Proteínas Serina-Treonina Quinasas/genética , Proteolisis , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ribonucleasas/metabolismo , Ribosomas/genética
2.
EMBO Rep ; 22(5): e51740, 2021 05 05.
Artículo en Inglés | MEDLINE | ID: mdl-33738926

RESUMEN

Stress granules (SGs) are dynamic condensates associated with protein misfolding diseases. They sequester stalled mRNAs and signaling factors, such as the mTORC1 subunit raptor, suggesting that SGs coordinate cell growth during and after stress. However, the molecular mechanisms linking SG dynamics and signaling remain undefined. We report that the chaperone Hsp90 is required for SG dissolution. Hsp90 binds and stabilizes the dual-specificity tyrosine-phosphorylation-regulated kinase 3 (DYRK3) in the cytosol. Upon Hsp90 inhibition, DYRK3 dissociates from Hsp90 and becomes inactive. Inactive DYRK3 is subjected to two different fates: it either partitions into SGs, where it is protected from irreversible aggregation, or it is degraded. In the presence of Hsp90, DYRK3 is active and promotes SG disassembly, restoring mTORC1 signaling and translation. Thus, Hsp90 links stress adaptation and cell growth by regulating the activity of a key kinase involved in condensate disassembly and translation restoration.


Asunto(s)
Gránulos Citoplasmáticos , Transducción de Señal , Citoplasma , Gránulos Citoplasmáticos/metabolismo , Diana Mecanicista del Complejo 1 de la Rapamicina/genética , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Fosforilación , ARN Mensajero/metabolismo
3.
J Pediatr ; 197: 104-108, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29650414

RESUMEN

OBJECTIVE: To evaluate the prevalence of joint laxity in children born preterm assessed in the first 2 years, the relationship between joint laxity and motor performance at preschool age, and possible changes over time in a subgroup of children followed longitudinally. STUDY DESIGN: The revised scale of Beighton Score was used to evaluate joint laxity in a population of 132 preschool children born preterm between 24 and 32 weeks of gestational age. All were assessed for joint laxity between 12 and 24 months of age. Children also performed the Movement Assessment Battery for Children-Second Edition between the age of 3 years and 6 months and 4 years; the age at onset of independent walking also was recorded. RESULTS: The total Beighton Score ranged between 0 and 8. Twenty percent of the cohort showed joint laxity. No differences related to sex or gestational age were observed. Children born preterm with joint laxity achieved later independent walking and achieved lower scores on Movement Assessment Battery for Children-Second Edition than those without joint laxity. In 76 children born preterm, an assessment for joint laxity was repeated once between 25 and 36 months and again after >36 months. No statistically significant difference was observed between the 3 assessments. CONCLUSIONS: The Beighton Score can be used to assess generalized joint laxity in children born preterm. As the presence of joint laxity influenced motor competences, the possibility to early identify these infants in the first 2 years is of interest to benefit from early intervention and potentially improve gross motor skills and coordination.


Asunto(s)
Inestabilidad de la Articulación/epidemiología , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Recien Nacido Prematuro , Italia/epidemiología , Estudios Longitudinales , Masculino , Prevalencia
4.
Int J Mol Sci ; 19(8)2018 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-30044455

RESUMEN

Recently, we showed that matrix metalloproteinase-12 (MMP-12) is highly expressed in microglia and myeloid infiltrates, which are presumably involved in blood⁻brain barrier (BBB) leakage and subsequent neuronal cell death that follows status epilepticus (SE). Here, we assessed the effects of a hydroxypyrone-based inhibitor selective for MMP-12 in the pilocarpine-induced SE rat model to determine hippocampal cell survival. In the hippocampus of rats treated with pilocarpine, intra-hippocampal injections of the MMP-12 inhibitor protected Cornu Ammonis 3 (CA3) and hilus of dentate gyrus neurons against cell death and limited the development of the ischemic-like lesion that typically develops in the CA3 stratum lacunosum-moleculare of the hippocampus. Furthermore, we showed that MMP-12 inhibition limited immunoglobulin G and albumin extravasation after SE, suggesting a reduction in BBB leakage. Finally, to rule out any possible involvement of seizure modulation in the neuroprotective effects of MMP-12 inhibition, neuroprotection was also observed in the retina of treated animals after optic nerve crush. Overall, these results support the hypothesis that MMP-12 inhibition can directly counteract neuronal cell death and that the specific hydroxypyrone-based inhibitor used in this study could be a potential therapeutic agent against neurological diseases/disorders characterized by an important inflammatory response and/or neuronal cell loss.


Asunto(s)
Inhibidores Enzimáticos/farmacología , Metaloproteinasa 12 de la Matriz/metabolismo , Fármacos Neuroprotectores/farmacología , Traumatismos del Nervio Óptico/tratamiento farmacológico , Pironas/química , Estado Epiléptico/metabolismo , Animales , Región CA3 Hipocampal/efectos de los fármacos , Región CA3 Hipocampal/patología , Giro Dentado/efectos de los fármacos , Giro Dentado/patología , Modelos Animales de Enfermedad , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/uso terapéutico , Humanos , Masculino , Ratones Endogámicos C57BL , Compresión Nerviosa/efectos adversos , Fármacos Neuroprotectores/química , Fármacos Neuroprotectores/uso terapéutico , Nervio Óptico/efectos de los fármacos , Nervio Óptico/patología , Pilocarpina/farmacología , Ratas , Convulsiones , Estado Epiléptico/inducido químicamente
5.
Epilepsy Behav ; 54: 30-3, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26630186

RESUMEN

The aim of this study was to investigate language disorders prospectively in patients with Dravet syndrome (DS) during the first years of life in order to identify their features and possibly the underlying mechanisms of the disease. At the Child Neurology Unit of Catholic University in Rome (Italy), thirteen patients with typical findings of DS were enrolled in the study. Full clinical observations, including neurological examination and long-term EEG monitoring, were prospectively and serially performed until a mean of 6years of age (range: 4years to 7years and 8months). The epileptic history was also collected in each case. In particular, developmental, cognitive, and detailed language assessments were performed with different tests according to the age of the patient. In addition to cognitive decline, characteristic language impairment was also found with a relative preservation of receptive abilities (comprehension) and a strong impairment of productive skills. This defect in sensorimotor verbal processing integration is discussed to highlight the possible mechanisms underlying cognitive decline.


Asunto(s)
Trastornos del Conocimiento/complicaciones , Epilepsias Mioclónicas/complicaciones , Trastornos del Desarrollo del Lenguaje/complicaciones , Desarrollo del Lenguaje , Niño , Preescolar , Comprensión , Electroencefalografía , Femenino , Humanos , Masculino , Examen Neurológico , Pruebas Neuropsicológicas
6.
J Neural Transm (Vienna) ; 121(12): 1431-49, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24866694

RESUMEN

The current view on the organization of the central nervous system (CNS) is basically anchored to the paradigm describing the brain as formed by networks of neurons interconnected by synapses. Synaptic contacts are a fundamental characteristic for describing CNS operations, but increasing evidence accumulated in the last 30 years pointed to a refinement of this view. A possible overcoming of the classical "neuroscience paradigm" will be here outlined, based on the following hypotheses: (1) the basic morpho-functional unit in the brain is a compartment of tissue (functional module) where different resident cells (not only neurons) work as an integrated unit; (2) in these complex networks, a spectrum of intercellular communication processes is exploited, that can be classified according to a dichotomous criterion: wiring transmission (occurring through physically delimited channels) and volume transmission (exploiting diffusion in the extracellular space); (3) the connections between cells can themselves be described as a network, leading to an information processing occurring at different levels from cell network down to molecular level; (4) recent evidence of the existence of specialized structures (microvesicles and tunneling nanotubes) for intercellular exchange of materials, could allow a further type of polymorphism of the CNS networks based on at least transient changes in cell phenotype. When compared to the classical paradigm, the proposed scheme of cellular organization could allow a strong increase of the degrees of freedom available to the whole system and then of its plasticity. Furthermore, long range coordination and correlation can be more easily accommodated within this framework.


Asunto(s)
Encéfalo/fisiología , Modelos Neurológicos , Vías Nerviosas/fisiología , Neuronas/fisiología , Transmisión Sináptica/fisiología , Animales , Humanos , Red Nerviosa
7.
Adv Sci (Weinh) ; 9(22): e2202062, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35618637

RESUMEN

Here, the authors report on the manufacturing and in vivo assessment of a bioresorbable nanostructured pH sensor. The sensor consists of a micrometer-thick porous silica membrane conformably coated layer-by-layer with a nanometer-thick multilayer stack of two polyelectrolytes labeled with a pH-insensitive fluorophore. The sensor fluorescence changes linearly with the pH value in the range 4 to 7.5 upon swelling/shrinking of the polymer multilayer and enables performing real-time measurements of the pH level with high stability, reproducibility, and accuracy, over 100 h of continuous operation. In vivo studies carried out implanting the sensor in the subcutis on the back of mice confirm real-time monitoring of the local pH level through skin. Full degradation of the pH sensor occurs in one week from implant in the animal model, and its biocompatibility after 2 months is confirmed by histological and fluorescence analyses. The proposed approach can be extended to the detection of other (bio)markers in vivo by engineering the functionality of one (at least) of the polyelectrolytes with suitable receptors, thus paving the way to implantable bioresorbable chemical sensors.


Asunto(s)
Implantes Absorbibles , Nanoestructuras , Animales , Concentración de Iones de Hidrógeno , Ratones , Polielectrolitos , Reproducibilidad de los Resultados
8.
J Recept Signal Transduct Res ; 31(5): 315-31, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21929287

RESUMEN

It has been estimated that at least 50% of the drugs available on the market act on G-protein coupled receptors (GPCRs) and most of these are basically or agonists or antagonists of this type of receptors. Herein, we propose new putative targets for drug development based on recent data on GPCR allosterism and on the existence of receptor mosaics (RMs). The main target for drug development is still GPCRs, but the focus is not the orthosteric binding pocket. According to the mosaic model of the plasma membrane, we mainly discuss the possibility of indirect modulatory pharmacological actions on expression/function of GPCRs. In particular, the following two new targets will be analyzed: a) The possibility of pharmacological interventions on the roamer-type of volume transmission (VT), which allow the intercellular transfer of set of signal molecules such as GPCRs, tetraspanins and ribonucleic acids. Thus, there is the possibility of pharmacological interventions on the decoding capabilities of neurons and/or glial cells by means of an action on composition and release of micro-vesicles. b) The possibility of pharmacological interventions on epigenetic mechanisms by taking into account their inter-relationships with GPCRs. As a matter of fact, there are epigenetic changes that are characteristic of periods of developmental plasticity that could provide a target for therapeutic intervention in the event of brain damage. We believe that almost all the biochemical knowledge presently available on GPCRs can be used in the development of these new pharmacological approaches.


Asunto(s)
Regulación Alostérica , Diseño de Fármacos , Epigénesis Genética , Microdominios de Membrana/química , Receptores Acoplados a Proteínas G/química , Tetraspaninas/química , Membrana Celular/química , Humanos
9.
Heliyon ; 7(12): e08648, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34957340

RESUMEN

The emergency created by Coronavirus disease 2019 (COVID-19) has inevitably changed human normal social and relational habits. The use of personal protective equipment, like surgical masks, by healthcare workers has been recommended to prevent human-to-human transmission of the novel coronavirus infection. However, the use of these masks could cause slight to considerable and reproducible changes in the infant's attitude towards the operator and health taker during routine clinical assessments. We reported a brief report on the impact of to the use of the surgical masks on the affective behaviour in 40 infants of age 2-9 months (study group) by using a scale to assess pain and distress among pediatric patients, the Face, Legs, Activity Cry and Consolability Scale (FLACC), and in 40 infants with the same ages and characteristics assessed before the COVID-19 pandemia onset (control group). Thirty-seven of the 40 infants in the study group had some signs of discomfort and appeared irritable and less prone to be engaged by the examiner with a different pattern of responses related to age with better responses for younger infants. These infants reported higher significant scores (p < 0.001) in the FLACC scale than those assessed before the COVID-19 onset. Infants appear to react negatively to the use of the surgical mask by the health operator. A different way to assess paediatric patients in early infancy with longitudinal studies should be proposed.

10.
Sleep Med ; 63: 137-141, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31627127

RESUMEN

OBJECTIVES: (i) to assess the presence of sleep disorders in a population of very preterm children (ie, with a gestational age [GA] ≤ 31 weeks) of preschool age with no history of neurological disabilities using a questionnaire standardized for this age group and (ii) to identify possible differences in a control group of term-born children. METHODS: A total of 146 low-risk preterm children (mean gestational age 28 weeks; range: 25-30), were assessed at a preschool age (mean age 3.8 years; range 3-6 years) using the sleep disturbance scale for children (SDSC) to assess sleep problems. As controls, 146 typically developing children matched for age and gender were also evaluated using the SDSC. RESULTS: An abnormal total sleep score (>70) was found in 7% of preterm children, while 21% had an abnormal score on at least one SDSC factor. No significant differences were reported according to the age of assessment or gestational age. The preterm group reported higher significant median scores on SDSC total, sleep-disordered breathing, sleep hyperhidrosis and difficulty in initiating and maintaining sleep factors. CONCLUSIONS: Low-risk very preterm children showed only a slightly higher incidence of sleep disorders than term-born peers at preschool age, with higher scores in specific sleep factors. These data could be useful to clinicians for screening those preterm children at risk for sleep disorders who need a more detailed assessment for a conclusive diagnosis and treatment.


Asunto(s)
Recien Nacido Extremadamente Prematuro , Trastornos del Sueño-Vigilia/epidemiología , Encuestas y Cuestionarios , Desarrollo Infantil , Preescolar , Femenino , Humanos , Incidencia , Masculino , Estudios Prospectivos , Instituciones Académicas
11.
J Clin Med ; 8(8)2019 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-31426574

RESUMEN

Early neurological assessment in infants with hypoxic ischemic encephalopathy (HIE) treated with hypothermia has not been systematically explored. The aims of the present study were to assess whether the Hammersmith Infant Neurological Examination (HINE) is a good tool to predict later neurodevelopmental outcomes at 2 year from birth in this population of infants. A total of 41 term born infants with HIE treated with hypothermia performed the HINE at 12 months and a neurodevelopmental assessment at 24 months. All the infants who had a global HINE score between 67 and 78 were able to walk independently at 2 years and reported a normal developmental quotient; language disorders were observed in a limited number of infants. HINE scores <67 were always associated with motor impairment. In conclusion, the HINE confirms its role as one of the early neurological examination tools for the diagnosis of high risk infants, even in infants with HIE treated with hypothermia. These results can be useful for clinicians involved in the follow up of these infants for early identification of motor disabilities and in planning appropriate intervention.

12.
Front Pharmacol ; 10: 1452, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31849688

RESUMEN

It is widely recognized that extracellular vesicles subserve non-classical signal transmission in the central nervous system. Here we assess if the astrocyte processes, that are recognized to play crucial roles in intercellular communication at the synapses and in neuron-astrocyte networks, could convey messages through extracellular vesicles. Our findings indicate, for the first time that freshly isolated astrocyte processes prepared from adult rat cerebral cortex, can indeed participate to signal transmission in central nervous system by releasing exosomes that by volume transmission might target near or long-distance sites. It is noteworthy that the exosomes released from the astrocyte processes proved ability to selectively target neurons. The astrocyte-derived exosomes were proven positive for neuroglobin, a protein functioning as neuroprotectant against cell insult; the possibility that exosomes might transfer neuroglobin to neurons would add a mechanism to the potential astrocytic neuroprotectant activity. Notably, the exosomes released from the processes of astrocytes maintained markers, which prove their parental astrocytic origin. This potentially allows the assessment of the cellular origin of exosomes that might be recovered from body fluids.

13.
FASEB J ; 21(14): 4028-37, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17622669

RESUMEN

Pharmacological activation of nicotinic acetylcholine receptors (nAChRs) exerts neuroprotective effects in cultured neurons and the intact animal. Much less is known about a physiological protective role of nAChRs. To understand whether endogenous activation of beta2* nAChRs contributes to the maintenance of the functional and morphological integrity of neural tissue, adult beta2-/- mice were subjected to in vivo challenges that cause neurodegeneration and cognitive impairment (intrahippocampal injection of the excitotoxin quinolinic acid), or neuroprotection and cognitive potentiation (2-month exposure to an enriched environment). The excitotoxic insult caused an increased deficit in the Morris water maze learning curve and increased loss of hippocampal pyramidal cells in beta2-/- mice. Exposure to an enriched environment improved performance in contextual and cued fear conditioning and object recognition tests in beta2+/+, whereas the improvement was absent in beta2-/- mice. In addition, beta2+/+, but not beta2-/-, mice exposed to an enriched environment showed a significant hypertrophy of the CA1/3 regions. Thus, lack of beta2* nAChRs increased susceptibility to an excitotoxic insult and diminished the positive effects of an enriched environment. These results may be relevant to understanding the pathophysiological consequences of the marked decrease in nAChRs that occurs in neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease.


Asunto(s)
Conducta Animal/efectos de los fármacos , Planificación Ambiental , Hipocampo/efectos de los fármacos , Neurotoxinas/administración & dosificación , Ácido Quinolínico/administración & dosificación , Receptores Nicotínicos/deficiencia , Receptores Nicotínicos/genética , Animales , Conducta Animal/fisiología , Conducta Exploratoria/efectos de los fármacos , Conducta Exploratoria/fisiología , Femenino , Hipocampo/metabolismo , Hipocampo/patología , Masculino , Aprendizaje por Laberinto/efectos de los fármacos , Aprendizaje por Laberinto/fisiología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Neurotoxinas/toxicidad , Unión Proteica/genética , Ácido Quinolínico/toxicidad , Receptores Nicotínicos/fisiología
14.
Neuroreport ; 19(6): 657-60, 2008 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-18382281

RESUMEN

The possible neuroprotective role of a novel and highly selective cyclooxygenase-2 inhibitor GW637185X was studied in a model of acute 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced injury of nigrostriatal dopaminergic (DA) neurons in the mouse. Stereological and microdensitometrical analysis of nigral tyrosine hydroxylase-immunoreactive cell bodies and striatal tyrosine hydroxylase-immunoreactive terminals, respectively, showed that GW637185X exerted a full protection against MPTP-induced degeneration of the nigro-striatal pathway. In contrast to earlier studies, these findings demonstrate that acute inhibition of cyclooxygenase-2 can result in a full neuroprotective effect not only on nigral DA cell bodies, but also on striatal DA terminals in the mouse MPTP model.


Asunto(s)
Encéfalo/efectos de los fármacos , Inhibidores de la Ciclooxigenasa 2/farmacología , Intoxicación por MPTP/tratamiento farmacológico , Degeneración Nerviosa/prevención & control , Fármacos Neuroprotectores/farmacología , Animales , Encéfalo/metabolismo , Encéfalo/patología , Dopamina/metabolismo , Inmunohistoquímica , Masculino , Ratones , Ratones Endogámicos C57BL , Degeneración Nerviosa/inducido químicamente , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Neuronas/patología , Tirosina 3-Monooxigenasa/metabolismo
15.
Brain Res Rev ; 55(1): 167-89, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17467058

RESUMEN

Since the discovery and mapping of the neuronal circuits of the brain by Golgi and Cajal neuroscientists have clearly spelled the fundamental questions which should be answered to delineate the arena for a scientific understanding of brain function: How neurons communicate with each other in a network? Is there some basic principle according to which brain networks are organised? Is it possible to map out brain regions specialised in carrying out some specific task? As far as the first point is concerned it is well known that Golgi and Cajal had opposite views on the interneuronal communication. Golgi suggested protoplasmic continuity and/or electrotonic spreading of currents between neurons. Cajal proposed the so-called "neuron doctrine", which maintained that neurons could communicate only via a specialised region of contiguity, namely the synapse. The present paper has the first and second points as main topics and last century progresses in these fields are viewed as developments of Golgi and Cajal's findings and above all, hypotheses. Thus, we will briefly discuss these topics moving from the transmitter based mapping, which brought neurochemistry into the Golgi-Cajal mapping of the brain with silver impregnation techniques. The mapping of transmitter-identified neurons in the brain represents one of the major foundations for neuropsychopharmacology and a reference frame for the biochemical and behavioural investigations of brain function. Biochemical techniques allowed giving evidence for multiple transmission lines in synapses interacting via receptor-receptor interactions postulated to be based on supramolecular aggregates, called receptor mosaics. Immunocytochemical and autoradiographic mapping techniques allowed the discovery of extra-synaptic receptors and of transmitter-receptor mismatches leading to the introduction of the volume transmission concept by Agnati-Fuxe teams. The Volume Transmission theory proposed the existence of a three-dimensional diffusion of e.g. transmitter and ion signals, released by any type of cell, in the extra-cellular space and the cerebrospinal fluid of the brain. Thus, a synthesis between Golgi and Cajal's views became possible, by considering two main modes of intercellular communication: volume transmission (VT) and wiring transmission (WT) (a prototype of the latter one is synaptic transmission) and two types of networks (cellular and molecular networks) in the central nervous system. This was the basis for the suggestion of two fundamental principles in brain morphological and functional organisation, the miniaturisation and hierarchic organisation. Finally, moving from Apathy's work, a new model of brain networks has recently been proposed. In fact, it has been proposed that a network of fibrils enmeshes the entire CNS forming a global molecular network (GMN) superimposed on the cellular networks.


Asunto(s)
Neuronas/fisiología , Neuronas/ultraestructura , Neurociencias/historia , Tinción con Nitrato de Plata/métodos , Animales , Comunicación Celular , Historia del Siglo XX , Historia del Siglo XXI , Humanos , Modelos Neurológicos , Redes Neurales de la Computación , Vías Nerviosas , Tinción con Nitrato de Plata/historia
16.
Brain Res Rev ; 55(1): 17-54, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17433836

RESUMEN

After Golgi-Cajal mapped neural circuits, the discovery and mapping of the central monoamine neurons opened up for a new understanding of interneuronal communication by indicating that another form of communication exists. For instance, it was found that dopamine may be released as a prolactin inhibitory factor from the median eminence, indicating an alternative mode of dopamine communication in the brain. Subsequently, the analysis of the locus coeruleus noradrenaline neurons demonstrated a novel type of lower brainstem neuron that monosynaptically and globally innervated the entire CNS. Furthermore, the ascending raphe serotonin neuron systems were found to globally innervate the forebrain with few synapses, and where deficits in serotonergic function appeared to play a major role in depression. We propose that serotonin reuptake inhibitors may produce antidepressant effects through increasing serotonergic neurotrophism in serotonin nerve cells and their targets by transactivation of receptor tyrosine kinases (RTK), involving direct or indirect receptor/RTK interactions. Early chemical neuroanatomical work on the monoamine neurons, involving primitive nervous systems and analysis of peptide neurons, indicated the existence of alternative modes of communication apart from synaptic transmission. In 1986, Agnati and Fuxe introduced the theory of two main types of intercellular communication in the brain: wiring and volume transmission (WT and VT). Synchronization of phasic activity in the monoamine cell clusters through electrotonic coupling and synaptic transmission (WT) enables optimal VT of monoamines in the target regions. Experimental work suggests an integration of WT and VT signals via receptor-receptor interactions, and a new theory of receptor-connexin interactions in electrical and mixed synapses is introduced. Consequently, a new model of brain function must be built, in which communication includes both WT and VT and receptor-receptor interactions in the integration of signals. This will lead to the unified execution of information handling and trophism for optimal brain function and survival.


Asunto(s)
Encéfalo/fisiología , Modelos Neurológicos , Red Nerviosa , Neuronas , Neurotransmisores/metabolismo , Tinción con Nitrato de Plata/métodos , Transmisión Sináptica/fisiología , Animales , Encéfalo/ultraestructura , Humanos , Red Nerviosa/fisiología , Red Nerviosa/ultraestructura , Neuronas/metabolismo , Neuronas/fisiología , Neuronas/ultraestructura
17.
J Pharm Biomed Anal ; 161: 1-11, 2018 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-30138822

RESUMEN

Cannabidiol (CBD), for long time considered as a minor cannabinoid of Cannabis sativa, has recently gained much attention due to its antioxidant, anti-inflammatory, analgesic and anticonvulsant properties. A liquid chromatography coupled to mass spectrometry based method was developed for the quantitative determination of CBD and other cannabinoids (Δ9-tetrahydrocannabinol (THC), 11-hydroxy-THC and 11-nor-9-carboxy-THC) in rat brain samples after oral administration of a single high dose (50 mg/kg) of CBD. The main challenge of the present work was to study CBD pharmacokinetics in rat cortex: the identification of its metabolites and pharmacodynamics through the study of variations in endogenous compounds' concentrations following CBD administration. An untargeted metabolomics approach revealed the formation of some CBD metabolites that are not commonly found in other body tissues or fluids. Lastly, the changes in some endogenous compounds' concentrations were correlated with some of the pharmacological properties of this cannabinoid.


Asunto(s)
Encéfalo/metabolismo , Cannabidiol/administración & dosificación , Cannabidiol/farmacocinética , Cromatografía Líquida de Alta Presión/métodos , Dronabinol/análogos & derivados , Dronabinol/análisis , Metabolómica , Espectrometría de Masas en Tándem/métodos , Animales , Cannabidiol/análogos & derivados , Cannabidiol/análisis , Ratas
18.
Curr Alzheimer Res ; 4(3): 305-13, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17627488

RESUMEN

Amyloid peptides (Abeta) are fragments of the Amyloid Precursor Protein (APP), an integral membrane protein. Abeta peptides are continuously generated by neurons and non-neuronal cells via sequential cleavage of APP by secretases. In particular, Abeta1-42 is the main component of the senile plaques associated with Alzheimer's disease (AD). Glial cells participate in the uptake of soluble extra-cellular Abeta and in the clearance of this material at localized sites where the Abeta are concentrated. It has been shown that clusterin (Apo J) and apolipoprotein E (ApoE) exert important additive effects in reducing Abeta deposition. In agreement with the fact that homocysteine (Hcy) potentiates Abeta peptide neurotoxicity, and Hcy brain levels increase with age, it has been demonstrated that high plasma levels of Hcy are a risk factor for AD. In the present paper, we used animals subjected to chronic intake of methionine (1 g/kg/day) in the drinking water, since this treatment can increase plasma Hcy levels by 30%. By means of this animal model, interactions between the Abeta beta-sheet rich fibrils and clusterin, have been evaluated in striata of animals after Abeta injection. Furthermore, it has been demonstrated that Abeta peptides are not only signals capable of activating astrocytes but also capable of reducing tyrosine-hydroxylase immunoreactivity in the basal ganglia probably leading to a reduction of volume transmission. These alterations in the neuroglial network morphology and function can, at least in part, explain the enhanced pain threshold observed in the Abeta intra-striatally injected animals.


Asunto(s)
Péptidos beta-Amiloides/farmacología , Núcleo Caudado/efectos de los fármacos , Clusterina/metabolismo , Hiperhomocisteinemia/metabolismo , Hiperhomocisteinemia/patología , Péptidos beta-Amiloides/química , Animales , Conducta Animal/efectos de los fármacos , Benzotiazoles , Interacciones Farmacológicas , Alimentos Formulados/efectos adversos , Homocisteína/sangre , Hiperhomocisteinemia/inducido químicamente , Masculino , Metionina , Modelos Biológicos , Dimensión del Dolor , Fragmentos de Péptidos/farmacología , Ratas , Ratas Sprague-Dawley , Tiempo de Reacción/fisiología , Tiazoles
19.
ScientificWorldJournal ; 7: 1073-81, 2007 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-17619790

RESUMEN

It has been demonstrated that some viruses, such as the cytomegalovirus, code for G-protein coupled receptors not only to elude the immune system, but also to redirect cellular signaling in the receptor networks of the host cells. In view of the existence of receptor-receptor interactions, the hypothesis is introduced that these viral-coded receptors not only operate as constitutively active monomers, but also can affect other receptor function by interacting with receptors of the host cell. Furthermore, it is suggested that viruses could also insert not single receptors (monomers), but clusters of receptors (receptor mosaics), altering the cell metabolism in a profound way. The prevention of viral receptor-induced changes in host receptor networks may give rise to novel antiviral drugs that counteract viral-induced disease.


Asunto(s)
Receptores Acoplados a Proteínas G/metabolismo , Transducción de Señal , Activación Viral/fisiología , Virosis/metabolismo , Virus/metabolismo
20.
Int J Mol Med ; 39(3): 487-497, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28204813

RESUMEN

In this review, the aspects and further developments of the concept of homeostasis are discussed also in the perspective of their possible impact in the clinical practice, particularly as far as psychic homeostasis is concerned. A brief historical survey and comments on the concept of homeostasis and allostasis are presented to introduce our proposal that is based on the classical assumption of the interstitial fluid (ISF) as the internal medium for multicellular organisms. However, the new concept of a hierarchic role of ISF of the various organs is introduced. Additionally, it is suggested that particularly for some chemico­physical parameters, oscillatory rhythms within their proper set­ranges should be considered a fundamental component of homeostasis. Against this background, we propose that the brain ISF has the highest hierarchic role in human beings, providing the optimal environment, not simply for brain cell survival, but also for brain complex functions and the oscillatory rhythms of some parameters, such as cerebrospinal fluid sodium and brain ISF pressure waves, which may play a crucial role in brain physio­pathological states. Thus, according to this proposal, the brain ISF represents the real internal medium since the maintenance of its dynamic intra-set-range homeostasis is the main factor for a free and independent life of higher vertebrates. Furthermore, the evolutionary links between brain and kidney and their synergistic role in H2O/Na balance and brain temperature control are discussed. Finally, it is surmised that these two interrelated parameters have deep effects on the Central Nervous System (CNS) higher integrative actions such those linked to psychic homeostasis.


Asunto(s)
Encéfalo/fisiología , Líquido Extracelular/metabolismo , Homeostasis , Animales , Evolución Biológica , Regulación de la Temperatura Corporal , Líquido Cefalorraquídeo/metabolismo , Retroalimentación Fisiológica , Humanos , Riñón/fisiología , Sodio/metabolismo
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