El procesamiento temporal en el Trastorno por Déficit de Atención e Hiperactividad

El procesamiento temporal es una actividad cerebral primordial para el adecuado funcionamiento de las personas en las actividades de la vida diaria y su afectación constituye uno de los signos de disfunción más importantes en el Trastorno por Déficit de Atención e Hiperactividad (TDAH). El objetivo de este trabajo es revisar los antecedentes y estudios científicos realizados sobre el procesamiento del tiempo en personas con TDAH, así como realizar una propuesta de valoración de esta función en poblaciones con este trastorno del neurodesarrollo. El procesamiento del tiempo ha sido poco estudiado clínicamente, aunque sí en el ámbito neurocientífico y experimental. La mayoría de los estudios se han basado en mecanismos relacionados con la percepción temporal y la reproducción de intervalos de tiempo a nivel motor, en los cuales se han descrito distorsiones en personas con TDAH. Se han propuesto diversas teorías basadas en una afectación primaria de la percepción del tiempo, aunque en otras ocasiones esta afectación se ha considerado secundaria a las alteraciones nucleares del trastorno. Entre las conclusiones del estudio destacamos que los procesos cognitivos relacionados con el procesamiento temporal son diversos y requieren del funcionamiento de distintos dominios cognitivos. Si bien se han desarrollado algunas pruebas para la evaluación de esta función, precisamos de nuevas herramientas para la adecuada valoración del procesamiento del tiempo en personas con TDAH. Palabras clave: Inatención; Hiperactividad; Impulsividad;Time Processing in Attention Deficit Hyperactivity Disorder. Time processing is a primary brain activity for the proper functioning of people in their daily activities. Its affectation is one of the most important signs of dysfunction in Attention Deficit Hyperactivity Disorder (ADHD). The aim was to review the background and scientific studies carried out on time processing in patients with ADHD, as well as top put forward a proposal for evaluating this function in populations with this neurodevelopmental disorder. Although time processing has not been studied clinically in detail, it has been approached experimentally in the neuroscientific field. Most studies of time processing have been based on functional phenomena related to time perception and timed motor reproductions; distortions of these two functions have been described in people with ADHD. Several theories based on a primary affectation of time processing have been proposed; however, on some occasions this affectation has been considered secondary to the nuclear alterations of the disorder. The cognitive processes related to temporal processing are rather diverse and require the functioning of different cognitive domains. Although some tests have been developed for the evaluation of this function, new tools are needed for the proper assessment of time processing in people with ADH

The spanish intergenerational study : beliefs, stereotypes, and metacognition about older people and grandparents to tackle ageism

Funding: The work received support from Memorial Mercedes Llort Sender 2021/80/09241941/4.Ageism can be seen as systematic stereotypes, prejudice, and discrimination of people because of their age. For a long time, society has accepted negative stereotypes as a norm. When referring to older adults, the United Nations Global Report on Ageism warns about a severe impact. The Intergenerational Study for a Healthy Aging, a questionnaire about believes, stereotypes, and knowledge about older people and grandparents, was administered to 326 Spanish biology and medical students. Here we report the results of stereotype analysis through adjective qualification of the youth and older people performed before the survey. Content analysis of two open questions about metacognition at the end of the survey is also presented. The results show that: (1) The questionnaire promoted metacognition; (2) Positive metacognition toward grandparents was higher than for the general old population; (3) Most participants were not conscious about ageism; (4) Gender was a key factor-male students were more ageist than females; (5) The feeling of guilt was higher in the questionnaire about older people; (6) The metacognition exercise elicited thoughts and, in few cases, the need to take action to tackle ageism. In conclusion, both activities promoted active thoughts about older people vs. grandparents and helped participants realize unconscious ageism-specifically toward the older population-serving as an awareness activity that may help tackle ageism

Molecular Characterization of Growth Hormone-producing Tumors in the GC Rat Model of Acromegaly

D.A.C. was supported by the Nicolás Monardes program of the Andalusian Ministry of Health (C-0015-2014) and by a grant from the Andalusian Ministry of Science and Innovation (CTS-7478). A.S-M and A.L.C were supported by grants from the ISCIII-Subdirección General de Evaluación y Fomento de la Investigación co-funded with Fondos FEDER (PI12/0143 and PI13/02043, respectively) and the Andalusian Regional Government (CTS-444) and a grant from Pfizer Spain. R.L.C. was supported by a grant from Andalusian Ministry of Health (PI0302-2012). R.M.L. was supported by grants from Proyecto de Investigación en Salud (FIS) PI13- 00651 (funded by Instituto de Salud Carlos III), CTS-1406, PI-0639-2012, BIO-0139 (funded by Junta de Andalucía) and by Ayuda Merck Serono 2013. J. P. C. was funded by a grant (BFU2013-43282-R) from Ministerio de Economía y Competitividad. CIBER is an initiative of Instituto de Salud Carlos III, Ministerio de Sanidad, Servicios Sociales e Igualdad, Spain. J.F.M.R. is supported by the “Sara Borrell” program from the Instituto de Salud Carlos III. R.M. Luque and J.P. Castaño have received grants and lecture fees from Ipsen and Novartis. E. Venegas-Moreno and A. Soto-Moreno received grants and lecture fees from Ipsen, Novartis and Pfizer. A. Leal-Cerro received grants from Novartis and Pfizer. David Cano received a grant from Novartis

Effects of transcranial Direct Current Stimulation (tDCS) on cortical activity: A computational modeling study.

International audienceAlthough it is well-admitted that transcranial Direct Current Stimulation (tDCS) allows for interacting with brain endogenous rhythms, the exact mechanisms by which externally-applied fields modulate the activity of neurons remain elusive. In this study a novel computational model (a neural mass model including subpopulations of pyramidal cells and inhibitory interneurons mediating synaptic currents with either slow or fast kinetics) of the cerebral cortex was elaborated to investigate the local effects of tDCS on neuronal populations based on an in-vivo experimental study. Model parameters were adjusted to reproduce evoked potentials (EPs) recorded from the somatosensory cortex of the rabbit in response to air-puffs applied on the whiskers. EPs were simulated under control condition (no tDCS) as well as under anodal and cathodal tDCS fields. Results first revealed that a feed-forward inhibition mechanism must be included in the model for accurate simulation of actual EPs (peaks and latencies). Interestingly, results revealed that externally-applied fields are also likely to affect interneurons. Indeed, when interneurons get polarized then the characteristics of simulated EPs become closer to those of real EPs. In particular, under anodal tDCS condition, more realistic EPs could be obtained when pyramidal cells were depolarized and, simultaneously, slow (resp. fast) interneurons became de- (resp. hyper-) polarized. Geometrical characteristics of interneurons might provide some explanations for this effect

Neurodevelopmental effects of undernutrition and placental underperfusion in fetal growth restriction rabbit models

Introduction: Chronic reduction of oxygen and nutrient delivery to the fetus has been related to neurodevelopmental problems. Placental underperfusion induces a significant reduction in oxygen and nutrient delivery, whereas maternal undernutrition causes mainly nutrient deficiency. A comparison of the neurodevelopmental effects of both situations in pregnant rabbits was performed. Materials and Methods: The placental underperfusion model was induced after uteroplacental vessel ligation at 25 days of pregnancy. The undernutrition model was induced after a reduction of 70% of the basal maternal intake at 22 days of pregnancy. Neurobehavioral tests were applied in the derived offspring at the neonatal period and over the long term. Structural brain differences were evaluated by brain networks obtained from diffusion magnetic resonance imaging. Results: Birth weight was significantly lower in both cases. However, stillbirth was only increased in the placental underperfusion model. Cases from both models presented poorer neurobehavioral performance and network infrastructure, being more pro-nounced in the placental underperfusion model. Discussion: Prenatal insults during the last third of gestation resulted in functional and structural disturbances. The degree of neurodevelopmental impairment and its association with structural brain reorganization seemed to be related to the type of the prenatal insult, showing stronger effects in the placental underperfusion model. (C) 2017 S. Karger AG, Base

Symptomatology Heterogeneity. Profiles Of Patients Diagnosed With Alzheimer's Type Dementia In Antioquia (Colombia)

Objetivo: Describir y contrastar la variabilidad sintomatológica de los casos con demencia tipo Alzheimer esporádico (DTA+E) con los datos obtenidos de los casos con demencia tipo Alzheimer familiar precoz causado por la mutación E280A del Neurobanco del Grupo de Neurociencias de Antioquia (GNA). Materiales y Método: Este estudio fue de tipo exploratoriodescriptivo y correlacional, se tomaron 83 casos de donantes con DTA almacenados en el Neurobanco del GNA. Estos casos se dividen en dos grupos, i) un grupo definido genéticamente como portador de la mutación E280A en el gen de la Presenilina1; y ii) otro grupo no portador de la mutación diagnosticado con Demencia Tipo Alzheimer Esporádico (DTA+E); se contrastaron los marcadores y/o características neuropsiquiatricas, neuropsicológicas, neurológicas y neuropatológicas de ambos grupos. Resultados: El síntoma que mostró mayores diferencias entre ambos grupos fue la repetidera (DTAF E280A fue de 1.2% y el grupo de DTA+E fue 18.4%). Otros síntomas como la depresión o el tiempo de aparición de pérdida progresiva de memoria no mostraron grandes diferencias entre grupos (DTAF E2080A=55.9%; DTA+E =53.1%) y (DTAF E2080A=55.9%; DTA+E =53.1%). Los trastornos del lenguaje que se observaron con mayor frecuencia entre los donantes fueron la pérdida del lenguaje, mutismo, anomia y afasia. El signo de mayor frecuencia en ambos grupos fue descontrol de esfínteres. La atrofia se registró con mayor intensidad en los lóbulos temporales de los cerebros de los donantes con DTA +E (83.3%). Los pesos del cerebro y del contenido de la fosa posterior, tienen una relación moderada, directamente proporcional y altamente significativa desde el punto de vista estadístico. Conclusiones: Existen diferencias neuropatológicas entre DTA+E y E280A que pueden estar asociadas a la fisiopatología de la forma hereditaria de E280A. Palabras claves: Demencia, AlzheimerObjective: To describe and contrast the symptomatic variability of cases with sporadic or non-sporadic Alzheimer's dementia (DTA + E) with the data obtained from the cases with early familial Alzheimer's dementia caused by the E280A of the Neurobank of the Neurosciences Group of Antioquia (GNA). Materials and Method: This study was of exploratory - descriptive and correlacional type, 83 donors' cases were taken with DTA stored in the Neurobank. These cases were divided in two groups, i) a group defined genetically like E280A; and ii) another not carrying group of the mutation (DTA+E); the scoreboards and / or characteristics neuropsychiatric, neuropsychological, neurological and neuropathological of both groups were confirmed. Results: The symptom that showed higher differences between both groups was iteration iteration (DTAF E280A with 1.2% and 18.4% for the DTA+E group). Other symptoms as depression or the time of appearance of progressive loss of memory did not show big differences among groups (DTAF E2080A=55.9%; DTA+E =53.1%) and (DTAF E2080A=55.9%; DTA+E =53.1%). The language disorders that were observed with major frequency among the donors were the loss of the language, mutism, anomia and aphasia. The sign with higher frequency in both groups was lost of sphincter control. The atrophy was with more intensity in the temporary lobes of the brains of the donors with DTA+E (83.3%). The weight of the brain and of the posterior fosse content, they have a moderate, directly proportional and highly significant relation from the statistical point of view. Conclusions: DTA +E has neuropathological differences with DTAF E280A that can be associated with the physiology hereditary from of DTAF E280A. Keywords: Dementia, Alzheime

Abnormal Capillary Vasodynamics Contribute to Ictal Neurodegeneration in Epilepsy

Seizure-driven brain damage in epilepsy accumulates over time, especially in the hippocampus, which can lead to sclerosis, cognitive decline, and death. Excitotoxicity is the prevalent model to explain ictal neurodegeneration. Current labeling technologies cannot distinguish between excitotoxicity and hypoxia, however, because they share common molecular mechanisms. This leaves open the possibility that undetected ischemic hypoxia, due to ictal blood flow restriction, could contribute to neurodegeneration previously ascribed to excitotoxicity. We tested this possibility with Confocal Laser Endomicroscopy (CLE) and novel stereological analyses in several models of epileptic mice. We found a higher number and magnitude of NG2+ mural-cell mediated capillary constrictions in the hippocampus of epileptic mice than in that of normal mice, in addition to spatial coupling between capillary constrictions and oxidative stressed neurons and neurodegeneration. These results reveal a role for hypoxia driven by capillary blood flow restriction in ictal neurodegeneration

Abnormal Capillary Vasodynamics Contribute to Ictal Neurodegeneration in Epilepsy

Seizure-driven brain damage in epilepsy accumulates over time, especially in the hippocampus, which can lead to sclerosis, cognitive decline, and death. Excitotoxicity is the prevalent model to explain ictal neurodegeneration. Current labeling technologies cannot distinguish between excitotoxicity and hypoxia, however, because they share common molecular mechanisms. This leaves open the possibility that undetected ischemic hypoxia, due to ictal blood flow restriction, could contribute to neurodegeneration previously ascribed to excitotoxicity. We tested this possibility with Confocal Laser Endomicroscopy (CLE) and novel stereological analyses in several models of epileptic mice. We found a higher number and magnitude of NG2+ mural-cell mediated capillary constrictions in the hippocampus of epileptic mice than in that of normal mice, in addition to spatial coupling between capillary constrictions and oxidative stressed neurons and neurodegeneration. These results reveal a role for hypoxia driven by capillary blood flow restriction in ictal neurodegeneration

Role of Reuniens Nucleus Projections to the Medial Prefrontal Cortex and to the Hippocampal Pyramidal CA1 Area in Associative Learning

We studied the interactions between short- and long-term plastic changes taking place during the acquisition of a classical eyeblink conditioning and following high-frequency stimulation (HFS) of the reuniens nucleus in behaving mice. Synaptic changes in strength were studied at the reuniens-medial prefrontal cortex (mPFC) and the reuniens-CA1 synapses. Input/output curves and a paired-pulse study enabled determining the functional capabilities of the two synapses and the optimal intensities to be applied at the reuniens nucleus during classical eyeblink conditioning and for HFS applied to the reuniens nucleus. Animals were conditioned using a trace paradigm, with a tone as conditioned stimulus (CS) and an electric shock to the trigeminal nerve as unconditioned stimulus (US). A single pulse was presented to the reuniens nucleus to evoke field EPSPs (fEPSPs) in mPFC and CA1 areas during the CS-US interval. No significant changes in synaptic strength were observed at the reuniens-mPFC and reuniens-CA1 synapses during the acquisition of eyelid conditioned responses (CRs). Two successive HFS sessions carried out during the first two conditioning days decreased the percentage of CRs, without evoking any long-term potentiation (LTP) at the recording sites. HFS of the reuniens nucleus also prevented the proper acquisition of an object discrimination task. A subsequent study revealed that HFS of the reuniens nucleus evoked a significant decrease of paired-pulse facilitation. In conclusion, reuniens nucleus projections to prefrontal and hippocampal circuits seem to participate in the acquisition of associative learning through a mechanism that does not required the development of LTP

The past, present and future challenges in epilepsy related and sudden deaths and biobanking.

Awareness and research on epilepsy-related deaths (ERD), in particular Sudden Unexpected Death in Epilepsy (SUDEP), have exponentially increased over the last two decades. Most publications have focused on guidelines that inform clinicians dealing with these deaths, educating patients, potential risk factors and mechanisms. There is a relative paucity of information available for pathologists who conduct these autopsies regarding appropriate post-mortem practice and investigations. As we move from recognizing SUDEP as the most common form of ERD toward in-depth investigations into its causes and prevention, health professionals involved with these autopsies and post-mortem procedure must remain fully informed. Systematizing a more comprehensive and consistent practice of examining these cases will facilitate 1) more precise determination of cause of death, 2) identification of SUDEP for improved epidemiological surveillance (the first step for an intervention study), and 3) bio-banking and cell-based research. This article reviews how pathologists and healthcare professionals have approached ERD, current practices, logistical problems and areas to improve and harmonize. The main neuropathology, cardiac and genetic findings in SUDEP are outlined, providing a framework for best practices, integration of clinical, pathologic and molecular genetic investigations in SUDEP, and ultimately prevention