Search results for "neuron"
showing 10 items of 2611 documents
Identification of inflammatory neuronal injury and prevention of neuronal damage in multiple sclerosis: hope for novel therapies?
2013
Importance Although multiple sclerosis (MS) has long been considered the prototype for an inflammatory, demyelinating disease of the central nervous system, modern histopathology and imaging techniques show that significant damage to neuronal structures already start occurring in the earliest stages of the disease. As the disease progresses, the extent of neuronal pathology accumulates. Therapeutic progress in terms of the prevention of increased disability has only just begun. Objective To review possible diagnostic improvements of neuronal compartment pathology as well as direct therapeutic interventions based on reports from the last decade and outline clinical results from studies and p…
Functional nicotinic acetylcholine receptors on subplate neurons in neonatal rat somatosensory cortex.
2004
The establishment of cortical synaptic circuits during early development requires the presence of subplate neurons (SPn's), a heterogeneous population of neurons capable to integrate and process synaptic information from the thalamus, cortical plate, and neighboring SPn's. An accumulation of cholinergic afferents and nicotinic acetylcholine receptors (nAChRs) has been documentated in the subplate around birth. To assess the developmental role of the cholinergic innervation onto SPn's, we used whole cell patch-clamp recordings of visually identified and biocytin-labeled SPn's in neonatal rat somatosensory cortex. Functional nAChRs were present in 92% of the investigated SPn's. Activation of…
Neuroglobin: A Respiratory Protein of the Nervous System
2004
Nerve tissues exhibit some of the highest oxygen consumption rates found in the body. Neuroglobin, a heme protein distantly related to hemoglobin, is thought to enhance the supply of oxygen to the neurons, the eye, and some endocrine tissues. Neuroglobin may promote neuronal survival under hypoxic conditions as they occur, for example, in stroke.
The role of N-methyl-D-asparate receptors in neurogenesis.
2006
The dentate gyrus continues to incorporate granule neurons during adulthood. Among the factors that we know modulate adult neurogenesis in the dentate gyrus, one of the first studied was the influence of excitatory amino-acids. These neurotransmitters, acting through NMDA receptors, are able to modulate both the proliferation of progenitor cells as well as the rate of neurogenesis in the adult dentate gyrus. However, the mechanisms by which these processes are influenced are not clearly known. Although there is no anatomical evidence of NMDA receptor expression in adult hippocampal progenitor cells or differentiating granule neurons, electrophysiological data and in vitro studies suggest th…
Selective culture of rat CNS neurons in a synthetic medium.
1983
A Chemically Defined Medium is described which facilitates the survival of neurons in primary cultures of rat cerebral hemispheres. More than 90% of all cells were identified as neurons using neurofilament as a marker in an immunocytochemical assay. In contrast, serum-supplemented medium, by stimulating nonneuronal cell proliferation, hinders the survival of neurons in culture.
Allosterically potentiating ligands of nicotinic receptors as a treatment strategy for Alzheimer's disease.
2000
Abstract One of the most prominent cholinergic deficit in Alzheimer’s disease (AD) is the reduced number of nicotinic acetylcholine receptors (nAChR) in the hippocampus and cortex of AD patients, as compared to age-matched controls. This deficit results in reduced nicotinic cholinergic excitation which may not only impair postsynaptic depolarization but also presynaptic neurotransmitter release and Ca 2+ -dependent intracellular signaling, including transcriptional activity. Presently, the most common approach to correct the nicotinic cholinergic deficit in AD is the application of cholinesterase inhibitors. Due to the resulting increase in synaptic acetylcholine levels, both in concentrati…
Multiple sclerosis – candidate mechanisms underlying CNS atrophy
2009
Recently it has become clear that the neuronal compartment plays a more important role than previously thought in the pathology of multiple sclerosis. Apart from demyelination, neuronal pathology is apparently largely responsible for the brain atrophy that can be observed early on and throughout the course of the disease. The loss of axons and their neurons in the course of chronic neuroinflammation is a major factor determining long-term disability in patients. The actual steps leading from immune attack against the myelin sheath to neuronal damage are not yet fully clear. Here we review key findings about direct axonal damage processes, demyelination-related neuronal pathology and cell-bo…
A window amplitude discriminator with adjustable upper and lower thresholds
1976
An amplitude window discriminator is described which permits selection of spikes from a multi-unit recording, provided the signal-to-noise ratio is high enough. The device can be built at relatively low cost and time. The circuitry permits analysis of the positive or the negative deflections of the recorded signals. In Part One of the circuitry, the signals are pre-amplified and may be inverted in polarity. In Part Two, the pulses are compared to a variable lower threshold voltage, and low amplitude noise is eliminated. Part Three depicts a logic circuit for elimination of disturbing high-amplitude signals, whose output delivers digital pulses, each corresponding to an original signal (e.g.…
Three-dimensional Hall effect accelerometer for recording head movements of freely moving laboratory animals
1991
A Hall effect device was constructed for a measurement of head movements in three spatial dimensions during classical conditioning experiments in cats. A Hall sensor was used to detect movements of a magnetic fragment floating in a small (15 x 15 mm) cube. The magnetic fragment was kept in the centre of the sealed cube with a thin coil spring which was filled with thin oil for damping excessive afteroscillations. A comparison of this device to a commercial accelerometer showed that the accuracy of the Hall device is sufficient for the movement recordings and that the device is sensitive also to slowly accelerating movements. The construction is compact and can be easily mounted, for example…
Neuronal network characteristics in the cat superior colliculus
1977
The system theoretical description of the superficial layers of neurons in the cat's superior colliculus is based on homogeneous linear space-time filters. The most important neurophysiological findings on the superior colliculus are simulated on the digital computer by generating suitable coupling functions and matching the space and time parameters. It is shown that the neurophysiological measurements can be interpreted by varying a few system parameters. The curves of velocity dependent responses, direction specificity and the effects of the colliculus specific surround are examined in particular. Computer simulation shows that such a surround can evaluate small moving stimuli differentl…