Search results for "pathways"
showing 10 items of 644 documents
Exploring Oscillatory Dysconnectivity Networks in Major Depression During Resting State Using Coupled Tensor Decomposition
2022
Dysconnectivity of large-scale brain networks has been linked to major depression disorder (MDD) during resting state. Recent researches show that the temporal evolution of brain networks regulated by oscillations reveals novel mechanisms and neural characteristics of MDD. Our study applied a novel coupled tensor decomposition model to investigate the dysconnectivity networks characterized by spatio-temporal-spectral modes of covariation in MDD using resting electroencephalography. The phase lag index is used to calculate the functional connectivity within each time window at each frequency bin. Then, two adjacency tensors with the dimension of time frequency connectivity subject are constr…
Does the renin-angiotensin system also regulate intra-ocular pressure?
2009
The renin-angiotensin-aldosterone system is known to play an essential role in controlling sodium balance and body fluid volumes, and thus blood pressure. In addition to the circulating system which regulates urgent cardiovascular responses, a tissue-localized renin-angiotensin system (RAS) regulates long-term changes in various organs. Many recognized RAS components have also been identified in the human eye. The highly vasoconstrictive angiotensin II (Ang II) is considered the key peptide in the circulatory RAS. However, the ultimate effect of RAS activation at tissue level is more complex, being based not only on the biological activity of Ang II but also on the activities of other produ…
[Paediatric cochlear implantation in the critical period of the auditory pathway, our experience].
2009
Numerous experimental and clinical studies have suggested a critical or sensitive period in which the auditory pathway develops its greatest potential in terms of plasticity and learning. Early cochlear implantation performed in prelingual deaf children in this period provides a better prognosis for language acquisition. The aim of this study is to show the importance of cochlear implantation before this critical period ends.We conducted an observational, longitudinal, retrospective study of 57 children suffering profound prelingual bilateral sensorineural hearing loss who had received Advanced Bionics implants at our ENT department between June, 1998, and November, 2006. Data on their audi…
Chelation of synaptic zinc induces overexcitation in the hilar mossy cells of the rat hippocampus.
2004
Complete removal of synaptic zinc by the chelator dietyldithiocarbamate (DEDTC; 500 mg/kg i.p.) in rat was followed by convulsive behaviour including wet dog shakes alternating immobility. Histological analysis 1 day after DEDTC administration detected expression of heat shock protein in the hippocampus restricted to hilar cells. These cells colocalize the marker for neurons and the glutamate receptor GluR2/3 showing that they are excitatory neurons. Additionally, they projected to the contralateral dentate gyrus. Therefore, they correspond to hilar mossy cells. These data show that the synaptic zinc has a role in normal hippocampus avoiding overexcitation, that would impair functionality e…
Oral medicine practice in Europe and Australia: Identifying practitioner characteristics and their clinical activity
2021
Oral Medicine is a young dental specialty born almost a century ago and deals with orofacial conditions not directly attributable to the most prevalent tooth pathologies such as dental caries or periodontal diseases. Presentations may reflect local disease or orofacial manifestations of more widespread pathology affecting other parts of the body. Due to its recency as a distinct discipline and to heterogeneous global settings, Oral Medicine has not yet achieved a shared scope and definition, as well as a recognized status across the globe. The current report presents survey data gathered from Oral Medicine practitioners in Europe and Australia and aimed to identify practitioner characterist…
Functional brain imaging: a window into the visuo-vestibular systems
2007
Advances have been made in identifying how areas involved in processing vestibular, ocular motor, and visual information are represented in the human cortex as well as the cortical interaction between these systems in healthy subjects.While we know how some vestibular and ocular motor disorders modify visuo-vestibular interaction by changing the 'normal' cortical activation-deactivation patterns, it is still early days in functional magnetic resonance imaging studies of patients with specific disorders. Findings from current brain imaging studies of several vestibular, ocular motor, and cerebellar disorders are presented.The promise of more insights into the complex neuronal networks of the…
Common etiological pathways between toxic substance use, Internet and cybersex addiction: The role of expectancies and antisocial deviance proneness
2016
This study examined Internet and cybersex addiction in adolescents and how such behaviour was associated with substance use (in particular, cigarettes, alcohol, and drug use). Participants were 312 adolescents, aged 14-16, who completed survey instruments. Study measures included demographic, toxic substance use, expectancies toward substances consumption, antisocial deviance proneness, Internet, and cybersex addiction variables. Descriptive, bivariate analyses, exploratory/confirmatory factor analyses, and structural Equation Modeling were performed. Nearly 60%, 26%, and 25% of adolescents reported having drunk alcohol, used drugs and smoked cigarettes respectively. Prevalence of Internet …
Molecular anatomy of the neuro-immune connection.
1991
Light microscopic immunohistochemistry was employed to elucidate and compare the presence, distribution, and coexistence of various peptides, neuroendocrine markers and enzymes of the catecholamine pathway in nerves supplying lymphoid tissues in a variety of mammalian species. All lymphoid organs and tissues receive innervation by fibers containing dopamine-beta-hydroxylase and/or tyrosine hydroxylase, neural markers like protein gene product 9.5, synaptophysin and neurofilament and a varied spectrum of peptides. The prominent peptides were tachykinins (substance P, neurokinin A), calcitonin gene-related peptide (CGRP), neuropeptide Y (NPY), and vasoactive intestinal polypeptide/peptide his…
Study and modulation of human cortical excitability with transcranial magnetic stimulation.
1998
Transcranial magnetic stimulation (TMS) can be applied in different paradigms to obtain a measure of various aspects of cortical excitability. These different TMS paradigms provide information about different neurotransmitter systems, enhance our understanding about the pathophysiology of neuropsychiatric conditions, and in the future may be helpful as a guide for pharmacological interventions. In addition, repetitive TMS (rTMS) modulates cortical excitability beyond the duration of the rTMS trains themselves. Depending on rTMS parameters, a lasting inhibition or facilitation of cortical excitability can be induced. These effects can be demonstrated neurophysiologically or by combining rTMS…
Modulation of hippocampal acetylcholine release after fimbria-fornix lesions and septal transplantation in rats
1997
Abstract Female Long–Evans rats sustained electrolytic lesions of the fimbria and the dorsal fornix causing a partial lesion of the septohippocampal pathway. Two weeks later, the rats received intra-hippocampal grafts of fetal septal cell suspensions. Nine to twelve months later, the release of acetylcholine (ACh) in the hippocampus of sham-operated, lesion-only and grafted rats was measured by microdialysis. The extent of cholinergic (re)innervation was determined by acetylcholinesterase (AChE) staining and densitometry. In both lesion-only and grafted rats, the ratio of ACh release to AChE staining intensity was increased as compared to sham-operated rats, indicating a loss of endogenous …