Search results for "cortical"

Metaplasticity of horizontal connections in the vicinity of focal laser lesions in rat visual cortex

2010

Focal cortical injuries are accompanied by a reorganization of the adjacent neuronal networks. An increased synaptic plasticity has been suggested to mediate, at least in part, this functional reorganization. Previous studies showed an increased long-term potentiation (LTP) at synapses formed by ascending fibres projecting onto layers 2/3 pyramidal cells following lesions in rat visual cortex. This could be important to establish new functional connections within a vertical cortical column. Importantly, horizontal intracortical connections constitute an optimal substrate to mediate the functional reorganization across different cortical columns. However, so far little is known about their p…

Studies on the apoptotic activity of natural and synthetic retinoids: discovery of a new class of synthetic terphenyls that potently support cell gro…

2005

New terphenyl derivatives have been synthesized and tested for their effect on cell survival in serum-free cultures. These compounds protected HL60 cells from death and supported their growth with an activity higher than that of the natural 14-hydroxy-retro-retinol. Terphenyls 26 and 28 also possess antiapoptotic activity on neuronal cells, proving them as possible candidates for the treatment of neurodegenerative and ischemic diseases.

GLOBAL AND REGIONAL CORTICAL THINNING IN FIRST-EPISODE SCHIZOPHRENIA PATIENTS: RELATIONSHIPS WITH CLINICAL AND COGNITIVE FEATURES

2010

Integration of local features into a global shape

2001

AbstractIt is a well-established fact that the cortical filters selective for spatial frequency and orientation have a limited spatial extent. The present study investigated how information from local filters is integrated into global shapes. Specifically, we were interested in whether identification of a global pattern consisting of small oriented, spatially-bandpass features (Gabor patches) depends on the orientations of those features. The observer was presented with a C-like stimulus shape comprised of oriented Gabor elements on a blank background, and the performance measure was the threshold contrast for identifying the global orientation of the C-shape (four possible rotated orientat…

Experts’ successful psychomotor performance was characterized by effective switch of motor and attentional control

2019

Abstract Objectives This study proposed that Mu (8–13 Hz) and SMR (12–15 Hz) readings in the sensorimotor cortical area can be used to investigate the cognitive mechanisms underlying optimal motor performance. Design This study used a within-subject design. Method Forty expert golfers were recruited to perform 60 putts while their EEGs were recorded. The putting distance was chosen to ensure that approximately 50% of all putts would be missed so that there was a need for constant adjustments to be made during performance. Successful performance was defined as the ball going in the hole. Results (a) Lower Mu power in Cz, and alpha power in Pz and Oz were observed for successful performances …

Valutazione comparativa delle sequenze fast Spin-echo e Spin-echo T2-dipendenti nella dimostrazione delle lesioni demielinizzanti encefaliche in cors…

1997

We compared T2-weighted fast spin-echo (FSE) magnetic resonance (MR) imaging and conventional spin-echo (CSE) T2-weighted imaging in the detection of brain lesions of multiple sclerosis (MS). 20 patients with clinically definite MS underwent brain imaging with both FSE and CSE T2-weighted imaging. There was no significant difference in total number of lesions detected on FSE vs CSE (1354 vs 1378). Slightly more periventricular and subcortical lesions were detected using CSE than FSE, whereas more posterior cranial fossa lesions were detected by FSE. There was no statistically significant difference in the signal intensity (SI) ratio of MS lesions to that of surrounding normal white matter …

Seeing with the visual cortex

1984

A short analysis of the input-output organization of the primary visual cortical areas in the cat and monkey is followed by a description of the salient microelectrophysiological properties of retino-geniculo-cortical system neurons. It is concluded that a strict hierarchical model of cortical processing of visual information is no longer tenable.

EVALUATION OF AUDITORY CORTICAL PLASTICITY FROM FIRST AMPLIFICATION TO ONE YEAR OF HEARING AID USE: THE RELATIONSHIP BETWEEN AIDED CORTICAL AUDITORY …

2021

Over the last decade, aided cortical auditory evoked potentials (ACAEPs) have continued to be a focus of interest due to the lack of adequate tools to objectively assess cortical auditory activity in response to amplified stimuli. The majority of authors have investigated the direct relationship between behavioral thresholds and ACAEPs and the evolution of ACAEP waves among children with sensorineural hearing loss (SNHL) undergoing rehabilitation. In contrast, scarce data are available regarding changes in ACAEPs over time in adult hearing aid users, particularly in relation to speech perception outcomes. The main goal of this project was to investigate the relationship between ACAEPs and s…

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 …

Cortical Bundles in the Persistent, Photosynthetic Stems of Cacti

1992

We examined 62 species in 45 genera of the cactus subfamily Cactoideae; all had collateral cortical bundles that permeated the broad, water-storing inner cortex and extended to the base of the outer, photosynthetic palisade cortex. Mean distance between cortical bundles was 0.75 mm, similar to the mean spacing (0.74 mm) of veins in leaves of Pereskia, a genus of relict leaf-bearing cacti. In 16 species, both young and extremely old stem cortex was available for study: in all of these, older bundles had larger amounts of phloem than did younger bundles, indicating that phloem had been produced for many years. In ten species, older bundles also had more xylem than younger bundles. In two gene…