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Organization of myelin in the mouse somatosensory barrel cortex and the effects of sensory deprivation.

In rodents, the barrel cortex is a specialized area within the somatosensory cortex that processes signals from the mystacial whiskers. We investigated the normal development of myelination in the barrel cortex of mice, as well as the effects of sensory deprivation on this pattern. Deprivation was achieved by trimming the whiskers on one side of the face every other day from birth. In control mice, myelin was not present until postnatal day 14 and did not show prominence until postnatal day 30; adult levels of myelination were reached by the end of the second postnatal month. Unbiased stereolo

Increased mirror movements after epileptic seizure in a case of polymicrogyria.

BACKGROUND: Mirror movements (MM) are involuntary movements during the voluntary movements of the contralateral homologous body parts. REVIEW SUMMARY: We report a patient with an increase in MM after suffering an epileptic seizure of his upper and lower limbs due to the right frontoparietal polymicrogyria, including the supplementary motor area as evidenced by magnetic resonance imaging. MM have been investigated using transcranial magnetic stimulation and other electrophysiological techniques in our case. CONCLUSION: This case is notable in that it is the first recorded observation of a pat

Lack of trigeminal nerve toxicity in rats exposed to trichloroethylene vapor for 13 weeks.

Male and female Fischer-344 rats were exposed to 1,1,2-trichloroethylene (TCE) at 250, 800, or 2500 ppm for 6 h/day, 5 days/week, for 13 weeks. Weekly body weights and daily clinical observations were recorded and a functional observational battery (FOB) was performed monthly. Postexposure neurotoxicological evaluations included an electrodiagnostic evaluation of auditory function, the trigeminal nerve, and a comprehensive neuropathological examination. After 8 weeks of exposure, female, but not male, rats exposed to 2500 ppm were slightly more reactive to handling than the controls but not af

Reduced influence of the ipsilateral ear on spatial tuning of auditory neurons in the albino superior colliculus: a knock-on effect of anomalies of the acoustic chiasm?

Auditory brainstem abnormalities affecting decussation patterns and nuclei involved in the acoustic chiasm exist in a variety of albino mammals, suggesting that binaural processes underlying spatial hearing may be disrupted in these mutants. To evaluate this we have compared the contribution of the two ears in albino and normally pigmented guinea pigs to the spatial tuning of auditory neurons in the deep layers of the superior colliculus (SC). Broadband noise stimuli at threshold and at suprathreshold intensities were presented from different azimuthal loudspeaker locations under free-field an

Chronic electrical stimulation of the auditory nerve using high surface area (HiQ) platinum electrodes.

High surface area cochlear implant electrodes with much smaller geometric surface areas than current designs might be used in the future to increase the number of stimulating electrodes along the carrier. Potential problems with an increase in charge density for a common stimulus resulting from decreasing the geometric surface area would be reduced by the enlarged real surface area of such electrodes. Electrochemically modified (HiQ) platinum (Pt) electrodes, with a real surface area approximately 75 times greater than the current standard Pt electrodes of the same geometric size, had shown in

Hypersomnia associated with a focal pontine lesion.

A 50-year-old woman developed intractable excessive sleepiness after undergoing the surgical removal of a brainstem cholesteatoma. The 24-hour ambulatory monitoring revealed a normal architecture of sleep contents, with 62.7% of the time spent in sleep. Auditory and somatosensory evoked responses showed abnormal patterns. The MRI scan of her brain showed an extensive nonprogressive lesion in the brainstem. We speculate that the problem underlying the patient's hypersomnia is a defect in the ascending reticular activating system (ARAS) rather than in the REM and NREM sleep mechanisms.

Neurophysiologic study of beta-thalassemia patients.

Neurophysiologic investigations were performed in 34 Chinese patients with beta-thalassemia major maintained on long-term desferrioxamine treatment to look for subclinical toxicity in the auditory, visual, peripheral, or central neural pathways. In the auditory pathway study, four patients (12%) had mild sensorineural hearing impairment. Two patients (6%) had increased P 100 latencies in the visual evoked potential study, and nine patients (26%) had abnormal electroretinogram results. All had normal electrooculograms. Ophthalmoscopic examination was abnormal in three patients (9%), and three (

Auditory and visual cortical activity during selective attention in fragile X syndrome: a cascade of processing deficiencies.

OBJECTIVE: This study examined whether attention deficits in fragile X syndrome (FXS) can be traced back to abnormalities in basic information processing. METHOD: Sixteen males with FXS and 22 age-matched control participants (mean age 29 years) performed a standard oddball task to examine selective attention in both auditory and visual modalities. Five FXS males were excluded from analysis because they performed below chance level on the auditory task. ERPs were recorded to investigate the N1, P2, N2b, and P3b components. RESULTS: N1 and N2b components were significantly enhanced in FXS mal

Comparison of central versus peripheral nerve pathways to the guinea pig inferior mesenteric ganglion determined electrophysiologically after chronic nerve section.

The contributions of central versus peripheral nerve pathways to neurons of the inferior mesenteric ganglion of guinea pigs were studied. Nerve trunks innervating neurons in the ganglion were surgically sectioned and intracellular electrical responses to nerve stimulation were measured 6-8 days after surgery. Guinea pigs were divided into two experimental groups: (1) those that had the lumbar sympathetic chain ganglia (LSG) L2 through L4 removed and (2) those that had the intermesenteric, lumbar colonic and hypogastric nerves sectioned leaving central connections intact. After 6-8 days fast ex

Conduction properties of epidurally recorded spinal cord potentials following lower limb stimulation in man.

Spinal somatosensory evoked potentials were recorded in 35 neurologically normal patients undergoing surgery for scoliosis. During posterior procedures the recording electrodes were placed in the dorsal epidural space and during anterior operations in the intervertebral discs. Stimulation was of the tibial nerve in the popliteal fossa and the posterior tibial and sural nerves at the ankle. At thoracic levels the response consisted of at least 3 components with different peripheral excitation thresholds and spinal conduction velocities (range 35-85 m/sec). All components were conducted mainly i…

Misinterpreting Electrophysiology in Human Cognitive Neuroscience.

An axiomatic view in contemporary neuroscience is that EEG components such as event-related brain potentials (ERPs) and oscillations are directly interpretable as manifestations of biological processes that support sensory, motor, and cognitive constructs of interest. This premise justifies and propels research programs in laboratories worldwide, but with a substantial social and economic cost, warranted by the potential for basic-science discovery and the resulting bench-to-bedside transfer for health and disease. But a different premise would be more fruitful. This article proposes that, in

Auditory brainstem response in the identification of cochlear synaptopathy in aged rodents: a systematic review with meta-analysis.

PURPOSE: This systematic review and meta-analysis evaluated the diagnostic performance of auditory brainstem response (ABR) for identifying age-related cochlear synaptopathies in rodents. METHOD: Following PRISMA guidelines, searches were conducted in PubMed/MEDLINE, Cochrane Library, Scopus, Embase, Web of Science, SciELO, LILACS, and gray literature. Studies evaluating CS in naturally aged rodents using short-latency auditory evoked potentials (AEPs) were included. Study selection, data extraction, risk-of-bias (JBI Critical Appraisal Checklist for Analytical Cross-Sectional Studies), and c…

N170 and N250 in schizophrenia spectrum disorder: systematic review and meta-analysis.

INTRODUCTION: Schizophrenia spectrum disorders (SSD) commonly involve deficits in social cognition and facial processing. The N170 and N250 event-related potentials (ERP), indexing perceptual and recognition stages of face processing respectively, have shown alterations in schizophrenia. Given diagnostic advances, an updated analysis is necessary to examine these ERP across SSD, including high-risk individuals and those exhibiting schizotypal traits. OBJECTIVES: To update previous meta-analysis findings by evaluating the effects of SSD on N170 and N250 amplitude and latency. METHOD: Studies

The Behavioural and Neurophysiological Effects of Set-for-Variability (SfV) Reading Intervention for Children With Sustained Word Reading Difficulties.

This study investigates whether a Set-for-Variability (SfV) reading intervention improves irregular word reading and induces neural changes in the N400, specifically earlier onset latency and increased negative amplitude in incongruent conditions, among children with persistent word reading difficulties (RD). A pre-registered randomised control trial (RCT) was conducted with 30 children (average age: 9 years). Over 10 weeks, participants completed a 15-h online reading program. The SfV group focused on phoneme variation in decoding both regular and exception words, while the Current Best Pract

[Preoperative Examination:Neuro-Otological Examination and Its Significance].

Neuro-otologic examinations are essential to identify lesion sites in patients with hearing and balance disorders. These tests assess the functions from the peripheral sensory organs to the central auditory and vestibular pathways. They are valuable for evaluating inner ear function and detecting central nervous system involvement. Auditory tests, such as pure-tone audiometry and auditory brainstem response, help localize lesions along the auditory neural pathway. Vestibular function can be assessed using the caloric test, video head impulse test, and vestibular evoked myogenic potentials, whi

The Role of Visual Electrophysiology in Systemic Hereditary Syndromes.

Visual electrophysiology is a valuable tool for evaluating the visual system in various systemic syndromes. This review highlights its clinical application in a selection of syndromes associated with hearing loss, mitochondrial dysfunction, obesity, and other multisystem disorders. Techniques such as full-field electroretinography (ffERG), multifocal electroretinography (mfERG), pattern electroretinography (PERG), visual evoked potentials (VEP), and electrooculography (EOG) offer insights into retinal and optic nerve function, often detecting abnormalities before clinical symptoms manifest. In…

Письмо редактору: комментарий к "первичному зрительскому повреждению коры головного мозга в результате транссинптического дегенерации после оптического нейрита: систематический обзор исследований нейроимации".

В настоящем письме рассматривается систематический обзор, проведенный " Хсиао " и др. " по транссинптической дегенерации (ТСР) в оптическом неуриите " (ОН), с уделением особого внимания нескольким областям для дальнейшей разведки в целях оптимизации клинического управления. Существенным пробелом является отсутствие индивидуализированного анатомического анализа мозга при оценке ОВД. Будущие исследования должны включать индивидуализированные модели мозга с использованием таких методов, как морфометрия на поверхности и объемный анализ, в целях более эффективной оценки ОВД и ру

Совпадение в аннотации оригинала
This letter addresses the systematic review by Hsiao et al. on trans-synaptic degeneration (TSD) in optic neuritis (ON), highlighting severa … thermore, the integration of functional imaging techniques such as functional MRI (fMRI) and visual evoked potentials (VEPs) with structural imaging can provide valuable insights into the functional impairments of the visual cortex and inform treatment decisions. Finally, integrating immune activity with neuroimaging can significantly improve patient management, pa …

Aligning Event-Related Potentials with Transcranial Alternating Current Stimulation for Modulation-a Review.

This review aims to demonstrate the connections between event-related potentials (ERPs), event-related oscillations (EROs), and non-invasive brain stimulation (NIBS), with a specific focus on transcranial alternating current stimulation (tACS). We begin with a short examination and discussion of the relation between ERPs and EROs. Then, we investigate the diverse fields of NIBS, highlighting tACS as a potent tool for modulating neural oscillations and influencing cognitive performance. Emphasizing the impact of tACS on individual ERP components, this article offers insights into the potential

Extended source analysis of movement related potentials (MRPs) for self-paced hand and foot movements demonstrates opposing cerebral and cerebellar laterality: a preliminary study.

The cerebellum is known to have extensive reciprocal connectivity with the cerebral cortex, including with prefrontal and posterior parietal cortex, which play an important role on the planning and execution of voluntary movement. In the present article we report an exploratory non-invasive electrophysiological study of the activity of the cerebellum and cerebrum during voluntary finger and foot movements. In a sample of five healthy adult subjects, we recorded EEG and the electro-cerebellogram (ECeG) with a 10% cerebellar extension montage during voluntary left and right index finger and foot

Temporary threshold shift in bottlenose dolphins exposed to steady-state, 1/6-octave noise centered at 0.5 to 80 kHza).

Temporary threshold shift (TTS) was measured in bottlenose dolphins after 1-h exposures to 1/6-octave noise centered at 0.5, 2, 8, 20, 40, and 80 kHz. Tests were conducted in netted ocean enclosures, with the dolphins free-swimming during noise exposures. Exposure levels were estimated using a combination of video-based measurement of dolphin position, calibrated exposure sound fields, and animal-borne archival recording tags. Hearing thresholds were measured before and after exposures using behavioral methods (0.5, 2, 8 kHz) or behavioral and electrophysiological [auditory brainstem response