Search results for "Cerebral"

Bilaterally recorded multiple-unit activity of the cingulate cortex during head turning conditioning with unilateral medial forebrain bundle stimulat…

1993

Cats were conditioned to turn their heads using a tone conditioned stimulus (CS) and medial forebrain bundle stimulation (MFB) unconditioned stimulus (US). The CS+ was delivered to one ear at a time, in random order, followed by the US. A tone of a different frequency was used as a CS-. The cats learned to respond differentially to the CSs showing head movements of greater acceleration to the CS+ than CS- over sessions. Bilateral recordings of cingulate cortex multiple-unit activity showed increased response amplitudes over sessions and larger responses in the hemisphere ipsilateral to the US. Since ipsilateral multiple-unit responses did not differ for the CSs, the asymmetry was probably d…

Event-Related Potentials and Autonomic Responses to a Change in Unattended Auditory Stimuli

1992

Event-related brain potentials (ERPs) and autonomic nervous system (ANS) responses to occasional pitch and rise-time changes in a task-irrelevant auditory stimulus repeating at short intervals were measured while the subject performed a difficult intellectual task (Raven Matrices). It was found that deviant stimuli elicited the mismatch negativity (MMN) component of the ERP even when they elicited no ANS response. There was no significant difference in the mismatch negativity between trials in which the skin conductance response was or was not elicited. The pitch deviant tone also elicited heart rate deceleration, whereas the rise-time deviant tone tended to elicit a later heart rate accele…

PSA-NCAM immunocytochemistry in the cerebral cortex and other telencephalic areas of the lizard Podarcis hispanica: differential expression during me…

2002

The lizard medial cortex, a region homologous to the mammalian dentate gyrus, shows postnatal neurogenesis and the surprising ability to replace its neurons after being lesioned specifically with the neurotoxin 3-acetylpyridine. As the polysialylated form of the neural cell adhesion molecule (PSA-NCAM) is expressed during neuronal migration and differentiation, we have studied its distribution in adult lizards and also during the lesion-regeneration process. In the medial cortex of control animals, many labeled fusiform somata, presumably corresponding to migratory neuroblasts, appeared in the inner plexiform layer. There were also scattered immunoreactive granule neurons in the cell layer.…

Description of the response of a new multi-parametric brain sensor to physiological and pathophysiological challenges in the cortex of juvenile pigs

2014

AIM Monitoring of intracranial pressure (ICP), local cerebral blood flow (CBF) and oxygen is part of modern intensive critical care medicine. Preclinical evaluation of newly developed catheters that should monitor several parameters simultaneously is reported poorly in the literature. The goal of our study was (1) to evaluate a new multi-parametric sensor in brain tissue and (2) to establish a testing protocol using pathophysiological challenges that target measured parameters of the sensor and autoregulatory boundaries and could be used as preclinical standard protocol in future studies. MATERIAL AND METHODS We describe data from 12 new multi-parametric brain sensors (MPBS) that were impla…

Pedaleo de brazos en personas con lesión medular, parálisis cerebral o ataxia cerebelosa: Parámetros fisiológicos. [Armcrank pedaling in persons with…

2016

espanolLos desordenes neurologicos generan afectacion fisica y derivan en sedentarismo, enfermedades coronarias y obesidad o diabetes, reduciendo tanto la esperanza como la calidad de vida. La oferta de actividad fisica adaptada es escasa por falta de informacion especifica sobre la forma de adecuarlo y dosificarlo a las personas que presentan estos desordenes. Con el fin de comparar el efecto del ejercicio de pedaleo de brazos sobre la respuesta fisiologica y la percepcion del esfuerzo, en 8 personas con lesion medular, 4 con paralisis cerebral y 4 con ataxia de Friedreich, se analizo su respuesta fisiologica, asi como su percepcion subjetiva al esfuerzo, frente a un grupo Control (16 part…

Initiation of high-frequency oscillatory ventilation and its effects upon cerebral circulation in pigs: an experimental study

2006

BACKGROUND: Current practice at high-frequency oscillatory ventilation (HFOV) initiation is a stepwise increase of the constant applied airway pressure to achieve lung recruitment. We hypothesized that HFOV would lead to more adverse cerebral haemodynamics than does pressure controlled ventilation (PCV) in the presence of experimental intracranial hypertension (IH) and acute lung injury (ALI) in pigs with similar mean airway pressure settings. METHODS: In 12 anesthetized pigs (24-27 kg) with IH and ALI, mean airway pressure (P(mean)) was increased (to 20, 25, 30 cm H(2)O every 30 min), either with HFOV or with PCV. The order of the two ventilatory modes (cross-over) was randomized. Mean art…

Dynamic cerebrovascular autoregulation in patients prone to postural syncope: Comparison of techniques assessing the autoregulation index from sponta…

2021

Abstract Three approaches to the assessment of cerebrovascular autoregulation (CA) via the computation of the autoregulation index (ARI) from spontaneous variability of mean arterial pressure (MAP) and mean cerebral blood flow velocity (MCBFV) were applied: 1) a time domain method (TDM); 2) a nonparametric method (nonPM); 3) a parametric method (PM). Performances were tested over matched and surrogate unmatched pairs. Data were analyzed at supine resting (REST) and during the early phase of 60° head-up tilt (TILT) in 13 subjects with previous history of postural syncope (SYNC, age: 28 ± 9 yrs.; 5 males) and 13 control individuals (noSYNC, age: 27 ± 8 yrs.; 5 males). Analysis was completed b…

Both contextual regularity and selective attention affect the reduction of precision‐weighted prediction errors but in distinct manners

2020

Predictive coding model of perception postulates that the primary objective of the brain is to infer the causes of sensory inputs by reducing prediction errors (i.e., the discrepancy between expected and actual information). Moreover, prediction errors are weighted by their precision (i.e., inverse variance), which quantifies the degree of certainty about the variables. There is accumulating evidence that the reduction of precision-weighted prediction errors can be affected by contextual regularity (as an external factor) and selective attention (as an internal factor). However, it is unclear whether the two factors function together or separately. Here we used electroencephalography (EEG) …

Il trasferimento di molecole tra cellule cerebrali è mediato anche da vescicole extracellulari

2013

Number Representation in Bilinguals. The role of early learning in the Mental Number Line representation

2016

La presente tesis tiene como objetivo el estudio de la matemática bilingüe dentro del ámbito científico de la Cognición Numérica y Bilingüismo. El abordaje de cómo las personas bilingües representan y acceden a la magnitud es actualmente una cuestión de creciente interés que responde a la necesidad de entender el papel que desempeña el lenguaje en la adquisición temprana de las matemáticas. Esa importancia se ve reflejada habitualmente en el contexto de la educación, en donde el aprendizaje de la aritmética y el bilingüismo concurren de forma natural. Dada la importancia que tiene en nuestra sociedad tanto la adquisición de las matemáticas como el aprendizaje de una segunda lengua en edades…