Search results for "nucleus"
showing 10 items of 1803 documents
Reduced oxytocin receptor gene expression and binding sites in different brain regions in schizophrenia: A post-mortem study
2016
Schizophrenia is a severe neuropsychiatric disorder with impairments in social cognition. Several brain regions have been implicated in social cognition, including the nucleus caudatus, prefrontal and temporal cortex, and cerebellum. Oxytocin is a critical modulator of social cognition and the formation and maintenance of social relationships and was shown to improve symptoms and social cognition in schizophrenia patients. However, it is unknown whether the oxytocin receptor is altered in the brain. Therefore, we used qRT-PCR and Ornithine Vasotocin Analog ([125I]OVTA)-based receptor autoradiography to investigate oxytocin receptor expression at both the mRNA and protein level in the left p…
Characterization of blink reflex interneurons by activation of diffuse noxious inhibitory controls in man.
1998
The blink reflex consists of an early, pontine R1-component and a late, medullary R2-component. R1 and R2 can be evoked by innocuous stimuli, but only the R2 also by painful heat, suggesting that the R2 is mediated by wide dynamic range neurons (WDR) of the spinal trigeminal nucleus. Remote noxious stimuli suppress the activity in WDR neurons via activation of diffuse noxious inhibitory controls (DNIC), whereas low-threshold mechanoreceptive neurons (LTM) are unaffected. In order to characterize the trigeminal interneurons of R1 and R2 we investigated the modulation of the blink reflex by remote painful heat. The blink reflex was elicited in 11 healthy subjects by innocuous electrical pulse…
Surprise: Unexpected Action Execution and Unexpected Inhibition Recruit the Same Fronto-Basal-Ganglia Network.
2020
Unexpected and thus surprising events are omnipresent and oftentimes require adaptive behavior such as unexpected inhibition or unexpected action. The current theory of unexpected events suggests that such unexpected events just like global stopping recruit a fronto-basal-ganglia network. A global suppressive effect impacting ongoing motor responses and cognition is specifically attributed to the subthalamic nucleus (STN). Previous studies either used separate tasks or presented unexpected, task-unrelated stimuli during response inhibition tasks to relate the neural signature of unexpected events to that of stopping. Here, we aimed to test these predictions using a within task design with i…
Medial Vestibular Nucleus Lesions in Wallenberg's Syndrome Cause Decreased Activity of the Contralateral Vestibular Cortex
2005
Three patients with the clinical diagnosis of Wallenberg's syndrome caused by acute unilateral ischemic infarctions, which included the vestibular nucleus in the medullary brain stem and afferent vestibular pathways, were examined by positron emission tomography (PET) during caloric vestibular stimulation. They all had typical signs of vestibular dysfunction such as transient rotatory vertigo with vomiting at the onset, ipsiversive body and ocular lateropulsion, and a complete ocular tilt reaction with tilts of the subjective visual vertical. Compared with healthy volunteers, who show activation in a network of temporoparietal vestibular areas within both hemispheres, especially in the post…
Cytological changes in the oral mucosa after use of a mouth rinse with alcohol. A prospective double blind control study
2012
Aim: The aim of this preliminary study was to detect cytological changes in the oral mucosa after using a mouth wash with alcohol. Material and Methods: A prospective double-blind, controlled study was performed, for 6 months. Group 1 consisted of 30 subjects who used a mouth rinse with 26.9% of alcohol [Listerine®] and Group 2 consisted of 30 subjects who used a mouth rinse with the same ingredients but with no alcohol. We obtained three cytological samples from the oral mucosa. The presence of cytological atypia, binucleation and karyorrhesis, and type of cells were studied. We also used a fluorescent in situ hybridization technique (FISH) in 15 samples in each group, for the micronucleus…
High striatal occupancy of D2-like dopamine receptors by amisulpride in the brain of patients with schizophrenia.
2003
The 'atypicality' of the antipsychotic drug, amisulpride, has been attributed to preferential extrastriatal binding. Previous investigations of striatal D2 receptor occupancy by amisulpride revealed conflicting results. The aim of this PET study was to measure the striatal occupancy by amisulpride and to correlate it with the corresponding drug plasma concentrations. Nine amisulpride-treated patients and 12 healthy volunteers serving as controls were studied with PET and [18F]desmethoxyfallypride. Occupancy values and plasma concentrations were nonlinearly fitted to an E max model. Results showed 43-85% (putamen) and 67-90% (caudate) D2-like receptor occupancy. Plasma amisulpride concentrat…
Convergence of nociceptive and non-nociceptive input onto the medullary dorsal horn in man
1998
Referred pain arising in orofacial pain states is probably due to convergence of different somatosensory input onto the medullary dorsal horn (MDH). To examine convergence between nociceptive and non-nociceptive input onto the MDH, the blink reflex (BR) was applied. R1- and R2-components can be evoked by innocuous stimuli, but only the R2 is elicited by painful heat. The BR was elicited by innocuous electrical stimuli applied to the supraorbital nerve. A conditioning painful heat pulse which did not evoke any BR was homotopically applied to the left forehead preceding the electrical stimulus by 75 ms. While R1 remained unchanged, the R2 was facilitated by about 30%. This study demonstrates …
Brain density in depression: methodological and psychopathological aspects
1988
The relationship between brain density, measured by computerized tomography (CT), and severity of depression was investigated in 44 patients with a major depressive episode according to DSM-III. In order to limit methodological problems, correlations between both the Brief Psychiatric Rating Scale (BPRS) and the Bech-Rafaelsen Melancholia Scale (BRMS) with density values were controlled for age, different ventricle measurements, brain size, and density and size of the skull. The BRMS score correlated inversely with density of the right thalamus, the right head of the caudate, and with parietal grey matter and occipital regions of both hemispheres. Similar, but nonsignificant results, were o…
The pterygoid reflex in man and its clinical application
1992
A technique for eliciting and recording the stretch reflex (R) of the medial pterygoid muscle (Pter) is described. The latency was 6.9 ± 0.43 ms in 23 healthy volunteers (mean age 23.7 years) showing a side-to-side difference of 0.29 ± 0.21 ms. The PterR latencies were little shorter and side-to-side difference little greater than of the masseter reflex. Observations in 5 selected patients with small brainstem lesions suggest that the neurons of the PterR afferents form a cluster within the caudal portion of the trigeminal mesencephalic nucleus. Testing the masseter and pterygoid reflexes provides a more precise localization of small ponto-mesencephalic lesions. © 1992 John Wiley & Sons, In…
Voxel-based morphometry depicts central compensation after vestibular neuritis.
2010
Objective Patients who have had vestibular neuritis (VN) show a remarkable clinical improvement especially in gait and posture >6 months after disease onset. Methods Voxel-based morphometry was used to detect the VN-induced changes in gray and white matter by means of structural magnetic resonance imaging. Twenty-two patients were compared an average 2.5 years after onset of VN to a healthy sex-and age-matched control group. Results Our analysis revealed that all patients had signal intensity increases for gray matter in the medial vestibular nuclei and the right gracile nucleus and for white matter in the area of the pontine commissural vestibular fibers. A relative atrophy was observed in…