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At least 613 records · Page 34Linked to original sources
PubMed1991

[Dysfunction in connection with functional disorders of the cervical spine].

In pain patients with functional disorder you can often find a disharmonie in the cervical spine. The results of the examination from 74 patients (47 female, 27 male) shows that: 1. 86.5% of the patients told about neck pain. Those patients with hard neck pain, you can find five or more dolent masticatory muscles. 2. 50% of the patients have on block in the cervical spine, 36.5% have between two and four blocks. 3. In patients with low neck pain you can find less blocks, than in patients with hard neck pain. If there is a block the part of the patients with more than five dolent muscles is significantly higher. 4. 64 patients who have a block shows at the same time 56.8% a functional disorder. So everybody can see that it is really necessary to work together in the diagnosis, therapy and treatment in patients with functional disorders.

Adolescent↗
PubMed1994

The teleostean torus longitudinalis: a short review on its structure, histochemistry, connectivity, possible function and phylogeny.

The older idea that the torus longitudinalis (TL) is part of the ascending cerebellotectal circuitry involved in control of eye movements is at odds with facts on the histological, hodological and physiological level. Instead of an input from the valvula cerebelli, the TL and the cerebellum both receive a collateral mossy fiber input from the same source (nucleus lateralis valvulae, dorsal tegmental nucleus). The new hodological information is more consistent with fine histological and physiological data and suggests that the TL is a link in premotor circuitry descending from telencephalon to brain stem.

Animals↗
PubMed1995

Functional synaptic connections made by regenerated retinal ganglion cell axons in the superior colliculus of adult hamsters.

Regenerated synaptic connections in the damaged mammalian visual system were studied in adult hamsters in which retinal ganglion cells (RGCs) regrew their axons through autologous peripheral nerve grafts directed from the stump of the transected optic nerve to the superior colliculus (SC). Unitary responses to illumination of small areas of the visual field were recorded within the superficial laminae of the reinnervated SC 23 to 60 weeks after grafting. Each element of a typical bursting response to light consisted of a terminal potential (TP) (half width 164 +/- 25 microseconds, amplitude up to 171 microV) arising from a regenerated RGC axon terminal arborization, followed at a latency of 268 +/- 63 microseconds by a longer duration negative focal synaptic potential (FSP) (half width 938 +/- 396 msec, amplitude up to 188 microV) reflecting EPSPs in neurons within the terminal field of the regenerated RGC axon. The FSP but not the TP was attenuated in a dose-dependent manner by iontophoretic application of GABA. In some cases spikes arose from FSPs after the first two or three impulses of a train, presumably reflecting summation of EPSPs to threshold for excitation in SC neurons contacted by the regenerated RGC axon terminals. Up to one-third of the area of the SC can be infiltrated by arborizations of the regenerated RGC axons that enter the SC through a nerve graft inserted in the lateral aspect of the SC. These experiments indicate that terminal arborizations of individual regenerated RGC axons can synapse with multiple neurons in the SC and that convergence of inputs from regenerated RGC axons is not required for activation of SC neurons in response to light.

Animals↗
PubMed2005

Mapping cortical activity elicited with electrical microstimulation using FMRI in the macaque.

Over the last two centuries, electrical microstimulation has been used to demonstrate causal links between neural activity and specific behaviors and cognitive functions. However, to establish these links it is imperative to characterize the cortical activity patterns that are elicited by stimulation locally around the electrode and in other functionally connected areas. We have developed a technique to record brain activity using the blood oxygen level dependent (BOLD) signal while applying electrical microstimulation to the primate brain. We find that the spread of activity around the electrode tip in macaque area V1 was larger than expected from calculations based on passive spread of current and therefore may reflect functional spread by way of horizontal connections. Consistent with this functional transynaptic spread we also obtained activation in expected projection sites in extrastriate visual areas, demonstrating the utility of our technique in uncovering in vivo functional connectivity maps.

Action Potentials↗
PubMed1999

[Aspects of cerebral connnectivity in schizophrenia. A comparative CBF study on treated schizophrenics before and after medication].

INTRODUCTION: The hypothesis of prefrontal-temporolimbic disconnectivity, considered to be relevant to the pathogenesis of schizophrenia, has been tested in 29 drug-naive schizophrenic patients, comparing the active with the remitted state. METHOD: A pre-post-treatment design was applied to 29 drug-naive schizophrenic inpatients, 18 male, mean age 32 years, 11 female, mean age 32 years, mean duration of illness 29 months. Psychopathological symptoms were assessed using PANSS, regional cerebral blood (rCBF) was measured by HMPAO-SPECT. RCBF values were calculated for 21 regions of interest after normalization to cerebellum, and plotted by Euklidean diagrams using the ordinal, nonmetric, multidimensional scaling method. These diagrams represent similarity correlations visualized as spatial distances. High correlation levels as indicated by small Euklidean distances have been interpreted as functional connectivity. RESULTS: In active schizophrenia, functional disconnectivity was observed between prefrontal and temporal cortex. After remission, connectivity was improved between temporolimbic and frontal cortex. CONCLUSION: Comparing active with remitted schizophrenia, a frontotemporal disconnectivity appears. Temporolimbic as well as frontolimbic connections restitute parallel to psychopathological improvement.

Adolescent↗
PubMed1986

Visuomotor fields of the superior colliculus: a quantitative model.

Electrophysiological and electrical stimulation studies in the monkey have disclosed that both the retinal surface and the metrics of saccades are topographically represented in the superior colliculus. This mapping of sensory and motor space onto the colliculus is nonhomogeneous in that the central region is over-represented in both the visual and the motor map. Single unit studies have revealed that visual receptive fields of collicular neurons are typically quite large and are characterized by a skewed (asymmetrical) sensitivity profile. Analyses by McIlwain [J. Neurophysiol. 38, 219-230 (1975)] in the cat have suggested that this skewness property reflects mainly the spatial distortion inherent in the afferent mapping. In this paper we describe a quantitative model, based on a logarithmic mapping function combined with a Gaussian connectivity function in the colliculus, which can account for the extent and the shape of collicular receptive fields. Collicular neurons in the deeper layers have movement-related bursts of activity for saccades in a limited amplitude and direction range related to their location in the collicular map. These movement fields, like visual receptive fields, may be quite extensive and typically have a skewed profile. In our model, an efferent-mapping function is defined, which relates the locus of a population of recruited cells to the metrics of the ensuing saccade. The parameters of this function, which was taken to be identical with the afferent mapping function, were estimated from Robinson's [Vision Res. 12, 1795-1808 (1972)] electrical stimulation data. Based on the assumption that the population-activity profile resembles a two-dimensional Gaussian function, the shape and the size of movement fields can then be described with just 2 or 3 free parameters. Electrophysiological data recorded from a small sample of collicular visuomotor neurons were used to illustrate the procedure, which we designed to enable application of our model to the experimental data. The best fit was obtained when the mapping function was slightly anisotropic. Suggestions on how the model could be improved and extended are offered in the Discussion.

Action Potentials↗