Search results for " brain"

Estimating brain connectivity when few data points are available: Perspectives and limitations

2017

Methods based on the use of multivariate autoregressive modeling (MVAR) have proved to be an accurate and flexible tool for the estimation of brain functional connectivity. The multivariate approach, however, implies the use of a model whose complexity (in terms of number of parameters) increases quadratically with the number of signals included in the problem. This can often lead to an underdetermined problem and to the condition of multicollinearity. The aim of this paper is to introduce and test an approach based on Ridge Regression combined with a modified version of the statistics usually adopted for these methods, to broaden the estimation of brain connectivity to those conditions in …

Pre- and post-ictal brain activity characterization using combined source decomposition and connectivity estimation in epileptic children

2019

In this research, the study of functional connectivity between sources of electroencephalogram (EEG) activity assessed for different classes (well before seizure, preictal and post-ictal) was performed. EEG recordings were acquired from 12 subjects with focal epilepsy. Then, ten common spatial patterns (CSP) were obtained for EEG segments describing 95% of Riemannian distance between pairs of classes, followed by estimation of multivariate autoregressive (MVAR) models’ coefficients. The MVAR models were further used to extract coherence as a functional connectivity measures. Our results show that the coherence between CSP sources differs between baseline and pre-ictal segments: it has the l…

MDMA Administration and Heat Shock Proteins Response: Foreseeing a Molecular Link

2010

Molecular and cellular mechanisms of MDMA-induced toxicity have been extensively studied in a number of experimental models. Nevertheless, only few studies investigated the involvement of HSPs ("molecular chaperones") in MDMA organs toxicity. In the present minireview we highlight this subject analysing the results of these studies conducted especially on brain tissue. Despite of it seems obvious that HSPs overexpression is a protective reaction against MDMA treatment, the molecular mechanisms for exerting their action are far to be undiscovered. At the same time, we need of comprehensive studies concerning the whole range of Hsps/chaperones expressions in all organs after acute and chronic…

The columnar gene vnd is required for tritocerebral neuromere formation during embryonic brain development of Drosophila.

2006

International audience; In Drosophila, evolutionarily conserved transcription factors are required for the specification of neural lineages along the anteroposterior and dorsoventral axes, such as Hox genes for anteroposterior and columnar genes for dorsoventral patterning. In this report, we analyse the role of the columnar patterning gene ventral nervous system defective (vnd) in embryonic brain development. Expression of vnd is observed in specific subsets of cells in all brain neuromeres. Loss-of-function analysis focussed on the tritocerebrum shows that inactivation of vnd results in regionalized axonal patterning defects, which are comparable with the brain phenotype caused by mutatio…

Neuroimaging for the anesthesiologist.

2007

Neuroimaging is essential in the treatment of cerebral nervous system disorders or in patients in the ICU with deterioration of their neurologic function. Leading clinical symptoms are acute neurologic deficits with different stages of hemisymptomatology, primary or progressing loss of consciousness or vigilance deficit, focal or generalized seizures, sometimes combined with an acute respiratory or circulatory insufficiency. The resulting questions can be summarized in those of intracranial space occupying hemorrhage; acute infarction; and signs for reduced cerebral blood flow, cerebrovascular vasospasm, or intracranial mass. Recent evolutions in imaging have contributed to an increase in d…

Extracellular Membrane Vesicles as Vehicles for Brain Cell-to-Cell Interactions in Physiological as well as Pathological Conditions.

2015

Extracellular vesicles are involved in a great variety of physiological events occurring in the nervous system, such as cross talk among neurons and glial cells in synapse development and function, integrated neuronal plasticity, neuronal-glial metabolic exchanges, and synthesis and dynamic renewal of myelin. Many of these EV-mediated processes depend on the exchange of proteins, mRNAs, and noncoding RNAs, including miRNAs, which occurs among glial and neuronal cells. In addition, production and exchange of EVs can be modified under pathological conditions, such as brain cancer and neurodegeneration. Like other cancer cells, brain tumours can use EVs to secrete factors, which allow escaping…

Modulation of hippocampal neurogenesis by Nano-Pulsed Laser Therapy

Neurogenesis is a physiological process through which new neurons are generated and it occurs throughout life, subverting the old dogma stating to the inability of the adult brain to replace neurons. Specifically, neurogenesis take place thanks to the presence of neuronal stem cells (NSCs) located in the subventricular zone of the lateral ventricle and in the subgranular zone of the dentate gyrus of the hippocampus. Data present in the literature demonstrate that neurogenesis in the hippocampus decreases during aging and it is impaired in neurodegenerative diseases, such as Alzheimer’s disease, and after traumatic brain injury (TBI). Traumatic Brain Injury (TBI) is a chronic disease that oc…

Il modello Brain-based e gli Habits of mind per potenziare la competenza linguistico-comunicativa nei futuri docenti. The Brain-based Model and the H…

2017

L’alternanza tra ricerca neurodidattica e le correlate teorie sulla mente, all’interno del dibattito scientifico nazionale, consentono una applicazione a diversi contesti disciplinari con l’intento di una complessiva implementazione del processo di insegnamento/apprendimento. Gli approcci glottodidattici di tipo brain-based, con particolare riferimento al Braingym (Mac Lean, 1975; Dennison, 2008) e le attività didattiche volte a consolidare gli Habits of Mind (Costa – Kallick, 2008) sono le cifre definitorie della ricerca qui descritta, condotta con 205 studenti del secondo anno del corso di laurea in Scienze della Formazione Primaria dell’Università di Palermo nell’A.A. 2015-2016. Attraver…

THE HABITS OF MIND AND THE BRAIN GYM FOR ENHANCEMENT OF TEACHERS’ COMMUNICATIVE-TEACHING COMPETENCE

2021

The hints offered both by Neuroeducation research and by the theories on the mind, within the national scientific debate, encourage reflection on possible ways of implementing the teaching / learning process. Communicative teaching approaches such the Brain-based ones, with particular reference to ‘Brain-gym’ (Mac Lean, 1975, Dennison, 2010) and educational activities aimed at developing the Habits of Mind (Costa & Kallick, 2008) are the keynotes of the present research, carried out with 385 secondary school teachers working in the province of Caltanissetta during the school year 2020/2021. Through the research process we wanted to verify the validity of the Brain-based model in order t…

Can we understand human brain development from experimental studies in rodents?

2020

Animal models are needed to gain an understanding of the genetic, molecular, cellular, and network mechanisms of human brain development. In rodents, a large spectrum of in vitro and in vivo approaches allows detailed analyses and specific experimental manipulations for studying the sequence of developmental steps in corticogenesis. Neurogenesis, neuronal migration, cellular differentiation, programmed cell death, synaptogenesis, and myelination are surprisingly similar in the rodent cortex and the human cortex. Spontaneous EEG activity in the pre- and early postnatal human cortex resembles the activity patterns recorded with intracortical multi-electrode arrays in newborn rodents. This ear…