Search results for "Neurophysiology"
showing 10 items of 196 documents
Lie Detection: fMRI
2019
Objective detection of deception was extensively studied, starting from polygraph to more modern techniques, the functional MR (fMRI), and they are based on neural (sympathetic) activation that is evoked in stressful conditions, such as lying. The role of fMRI in neurophysiology has been extensively developed and studied, and its principles lie in the correlation between the brain demand of energy during determined task and its supply. Although being extensively studied, its role for judiciary purpose presents many shortcomings.
Longitudinal CSF proteome profiling in mice to uncover the acute and sustained mechanisms of action of rapid acting antidepressant (2R,6R)-hydroxynor…
2021
Delayed onset of antidepressant action is a shortcoming in depression treatment. Ketamine and its metabolite (2R,6R)-hydroxynorketamine (HNK) have emerged as promising rapid-acting antidepressants. However, their mechanism of action remains unknown. In this study, we first described the anxious and depression-prone inbred mouse strain, DBA/2J, as an animal model to assess the antidepressant-like effects of ketamine and HNK in vivo. To decode the molecular mechanisms mediating HNK's rapid antidepressant effects, a longitudinal cerebrospinal fluid (CSF) proteome profiling of its acute and sustained effects was conducted using an unbiased, hypothesis-free mass spectrometry-based proteomics app…
Indirect assessment of an interpretation bias in humans: Neurophysiological and behavioral correlates
2013
Affective state can influence cognition leading to biased information processing, interpretation, attention, and memory. Such bias has been reported to be essential for the onset and maintenance of different psychopathologies, particularly affective disorders. However, empirical evidence has been very heterogeneous and little is known about the neurophysiological mechanisms underlying cognitive bias and its time-course. We therefore investigated the interpretation of ambiguous stimuli as indicators of biased information processing with an ambiguous cue-conditioning paradigm. In an acquisition phase, participants learned to discriminate two tones of different frequency, which acquired emotio…
Migraine as a Cortical Brain Disorder
2020
Purpose Migraine is an exclusively human chronic disorder with ictal manifestations characterized by a multifaceted clinical complexity pointing to a cerebral cortical involvement. The present review is aimed to cover the clinical, neuroimaging, and neurophysiological literature on the role of the cerebral cortex in migraine pathophysiology. Overview Converging clinical scenarios, advanced neuroimaging data, and experimental neurophysiological findings, indicate that fluctuating excitability, plasticity, and metabolism of cortical neurons represent the pathophysiological substrate of the migraine cycle. Abnormal cortical responsivity and sensory processing coupled to a mismatch between the …
Adaptive-threshold neural spike detection by noise-envelope tracking
2007
A new method for adaptive threshold setting is implemented and used in two threshold-based spike detectors: simple threshold and nonlinear energy operator. Detection quality assessment is performed using both a set of artificially generated signals and a real neural recording. Receiver operating curves are obtained and results show that, compared to fix threshold, adaptive threshold setting yields performance improvement.
A computational model for motor learning in insects
2013
The aim of this paper is to propose a computational model, inspired by Drosophila melanogaster, able to handle problems related to motor learning. The role of the Mushroom Bodies and the Central Complex in solving this problem is analyzed and plausible biologically inspired models are proposed. The designed computational models have been evaluated in simulation using a dynamic structure inspired by the fruit fly. The obtained results open the way to new neurobiological experiments focused to better understand the underlined mechanisms involved, to verify the feasibility of the hypotheses formulated and the significance of the obtained results.
Neurobiologie und System-Theorie eines visuellen Muster-Erkennungsmechanismus bei Kröten
1973
Quantitative behavioral experiments have shown that the toad uses mainly two types of gestalt information in prey/enemy discrimination: pattern extension in the direction of movement promotes, in general, the signal value prey, while extension perpendicular to the direction of movement promotes that of enemy. Registrations from single fibers and single cells at different stages on the visual path showed that the object extension perpendicular to the direction of movement is chiefly analysed by means of the retinal and thalamus pretectal nerve nets, whereas the extension in the direction of movement is analysed mostly by certain tectal nerve nets. Further neurobiological findings indicated t…
Machine learning for a combined electroencephalographic anesthesia index to detect awareness under anesthesia
2020
Spontaneous electroencephalogram (EEG) and auditory evoked potentials (AEP) have been suggested to monitor the level of consciousness during anesthesia. As both signals reflect different neuronal pathways, a combination of parameters from both signals may provide broader information about the brain status during anesthesia. Appropriate parameter selection and combination to a single index is crucial to take advantage of this potential. The field of machine learning offers algorithms for both parameter selection and combination. In this study, several established machine learning approaches including a method for the selection of suitable signal parameters and classification algorithms are a…
Altered processing of sensory stimuli in patients with migraine.
2014
Migraine is a cyclic disorder, in which functional and morphological brain changes fluctuate over time, culminating periodically in an attack. In the migrainous brain, temporal processing of external stimuli and sequential recruitment of neuronal networks are often dysfunctional. These changes reflect complex CNS dysfunction patterns. Assessment of multimodal evoked potentials and nociceptive reflex responses can reveal altered patterns of the brain's electrophysiological activity, thereby aiding our understanding of the pathophysiology of migraine. In this Review, we summarize the most important findings on temporal processing of evoked and reflex responses in migraine. Considering these d…
Imaging synaptic zinc release in living nervous tissue
2001
Zinc enriched neurons have a pool of synaptic vesicles which contain free or loosely-bound zinc ions. The movement of the vesicular zinc ions into the synaptic clefts has been previously studied by microdialysis, fluorescence postmortem staining for zinc and radioactive zinc isotope. In this study the zinc fluorescence probe N-6-metoxy-p-toluensulfonamide quinoline (TSQ) has been applied as a tracer of synaptic release of zinc ions. This fluorochrome permeates cell membranes and when exposed to living brain slices gives rise to a staining pattern similar to that seen with autometallography. In the living brain slices, fluorescence emission persists after exposure to calcium saturated ethyle…