PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “OLFACTORY NERVE”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,585 records · Page 88Linked to original sources
PubMed1996

Ontogenetic changes in neuropeptide Y-like-immunoreactivity in the terminal nerve of the chum salmon and the cloudy dogfish, with special reference to colocalization with gonadotropin-releasing hormone-immunoreactivity.

We observed ontogenetic changes of neuropeptide Y (NPY)-like-immunoreactivity in the terminal nerve (TN) of the chum salmon, a teleost, and the cloudy dogfish, an elasmobranch. In the chum salmon, NPY-like-immunoreactive (NPY-IR) cells first appeared in the olfactory placode of embryos at 16 days after fertilization, and then extended sequentially and centrally in the olfactory system. Colocalization of NPY- and gonadotropin-releasing hormone (GnRH)-like-immunoreactivities was also observed in TN ganglion cells. In the cloudy dogfish, NPY-IR cells first appeared in the rudimental TN ganglion of the embryo at the 40 mm stage. Then, the NPY-IR cells and fibers in the TN system increased in density during late embryonic periods. Colocalization of NPY- and GnRH-like-immunoreactivities in TN ganglion cells was not found in the developing or the adult dogfish.

Age Factors↗
PubMed1992

[Unusual localization of an olfactory esthesioneuroma].

Olfactory neuroblastoma, a nerve tumour arising in the olfactory mucosa, is a relatively easy diagnosis in the case of a mass centered around the cribriform plate. It is more difficult to diagnose in its exceptional ectopic forms (maxillary sinus) in the absence of any cytological and histochemical arguments (fibrils, olfactory rosettes). Its local malignancy is variable with a 42% 5-year survival for stage C and metastases in 30% of cases (principally cervical nodes, bone and liver). The role of imaging is to define the criteria of a mass syndrome and to perform the preoperative staging in a case of apparently simple sinus obstruction.

Brain Neoplasms↗
PubMed1984

Asymmetry of the olfactory system in the brain of the winter flounder, Pseudopleuronectes americanus.

Adult flatfishes exhibit grossly asymmetric external morphology. Even the olfactory apparatus is asymmetric, being larger on the upward-facing side. We undertook the present study on the winter flounder, Pseudopleuronectes americanus, to examine whether the asymmetry of the peripheral olfactory system is maintained in its central organization. In winter flounder, the right olfactory organ, nerve, and bulb are larger than the contralateral counterparts. In addition, the right telencephalon is about 8% larger than the left. Horseradish peroxidase (HRP) and degeneration techniques were used to trace the central connections of the olfactory bulbs. Neurons afferent to the olfactory bulb occur bilaterally in the telencephalon and mesencephalic tegmentum. Afferent neurons are also present at the junction between the posterodorsal bulb and telencephalon, in the basal preoptic region, nucleus of the posterior tuber, locus coeruleus, raphe nucleus, and the contralateral bulb. Each olfactory bulb projects bilaterally to several restricted areas of the telencephalon, the posterodorsal neurons of the nucleus preopticus and the tuberal region, with ipsilateral connections being heavier in all areas. Corresponding to the differences in the peripheral olfactory apparatus, the central olfactory projections were also asymmetric. The right olfactory bulb projects to 2.6% of the ipsilateral telencephalon and 1.99% of the contralateral telencephalon. The left bulb projects to 1.8% of the ipsilateral and 0.6% of the contralateral telencephalic hemisphere. Thus the left telencephalon receives roughly equal olfactory input from the two sides, while the right telencephalon receives vastly more input from the right olfactory system. The asymmetry in the projections of the right and left bulbs may be due to differential postmetamorphic growth of the olfactory system on the two sides.

Animals↗
PubMed1975

Binding of tetrodotoxin and saxitoxin to sodium channels.

A useful first step in any chemical characterization of the sodium channels in nerve membrane would clearly be the identification of some measurable property of the channel that does not depend on the intactness of the tissue. To this end, tetrodotoxin and saxitoxin, which bind specifically to sodium channels, have been triated and their binding to rabbit, lobster and garfish non-lyelinated nerve fibres examined. In each case, a component of the binding curve was found that saturated at concentrations of a few nanomolar. In addition, non-specific binding, indicated by a linear dependence of the amount bound on concentration, occurred. A solubilized membrane preparation from garfish nerve shows the same specific binding component as that of the intact nerve. The saturable component of binding seems to reflect the sodium channel density in nerve, and this is extremely small, being about 27/mum-2 in the rabbit nerve and as small as 6/mum-2 in the garfish nerve.

Animals↗
PubMed1997

Distribution and characteristics of cholecystokinin-like immunoreactivity in the olfactory bulb of the cat.

The distribution and characteristics of cholecystokinin (CCK)-like immunoreactive (LIR) nerve fibers was examined in the cat olfactory bulb using immunohistochemistry. CCK-LIR cell bodies were not found; fine varicose CCK-LIR fibers were observed in the most layers. In the main olfactory bulb, no staining was seen in the olfactory nerve layer and white matter. The directions of CCK-LIR fibers in the glomerular, external plexiform and mitral cell layers were generally perpendicular to the bulbar surface; those in the deep granule cell layer were parallel; and those in the internal plexiform and superficial granule cell layers were mixed. In the accessory olfactory bulb, CCK-LIR fibers were localized only in the granule cell layer. The presence of CCK-LIR fibers of the cat olfactory bulb may be involved in the modulation of olfactory transmission.

Animals↗
PubMed1995

Identification of the Ulex europaeus agglutinin-I-binding protein as a unique glycoform of the neural cell adhesion molecule in the olfactory sensory axons of adults rats.

Histochemical localization of two lectins, Ulex europaeus agglutinin-I (UEA-I) and Tetragonolobus purpureus (TPA), was studied in the olfactory bulb of adult rats. In contrast to TPA, UEA-I detected a fucosylated glycoprotein that is only present in the surface membranes of olfactory sensory cells including the whole course of their neurites up to the final arborization in glomeruli. Immunoblotting revealed that UEA-I binds specifically to a protein of 205 kDa, while TPA stains several other glycoproteins. Affinity chromatography with the use of a UEA-I column identified the 205 kDa protein as a glycoform of neural cell adhesion molecule (N-CAM), specific for the rat olfactory sensory nerves.

Agglutinins↗
PubMed1992

Cell migration from the olfactory neuroepithelium of neonatal and adult rodents.

This study reports the presence of olfactory cell clusters in postnatal and adult animals within the lamina propria of the olfactory mucosa and the nerve fiber layer of the olfactory bulb. The results obtained from mice and rats, partially or totally unilaterally bulbectomized, have been compared with observations in intact control animals. Light microscopic observation has shown that, in bulbectomized animals, the clusters are present in both experimental and normal sides and are usually associated with olfactory axon bundles. Moreover, when compared with intact animals, differences are present in terms of number of clusters and regions from where they originate. The morphological identity of the cells of the clusters with the globose basal cell of the olfactory neuroepithelium could be demonstrated with the electron microscope. By autoradiographic means, it was possible to show that they originate from the olfactory neurogenetic matrix and migrate along olfactory axon bundles. Interestingly, the migrating cells do not express olfactory marker protein. Altogether, these observations suggest that the olfactory matrix may be capable of originating neural elements other than olfactory receptor neurons.

Aging↗
PubMed1999

A mobile high-field magnetic resonance system for neurosurgery.

OBJECT: The authors' goal was to place a mobile, 1.5-tesla magnetic resonance (MR) imaging system into a neurosurgical operating room without adversely affecting established neurosurgical management. The system would help to plan accurate surgical corridors, confirm the accomplishment of operative objectives, and detect acute complications such as hemorrhage or ischemia. METHODS: The authors used an actively shielded 1.5-tesla magnet, together with 15 mtesla/m gradients, MR console computers, gradient amplifiers, a titanium, hydraulic-controlled operating table, and a radiofrequency coil that can be disassembled. The magnet is moved to and from the surgical field by using overhead crane technology. To date, the system has provided unfettered access in 46 neurosurgical patients. In all patients, high-definition T1- and/or T2-weighted images were rapidly and reproducibly acquired at various stages of the surgical procedures. Eleven patients underwent craniotomy that was optimized after preincision imaging. In four patients who harbored subtotally resected tumor, intraoperative MR imaging aided the surgeon in removing the remaining tumor. Interestingly, the intraoperative administration of gadolinium demonstrated a dynamic expansion of enhancement beyond the preoperative contrast contour in patients with malignant glioma. These zones of new enhancement proved, on examination of biopsy samples, to be tumor. CONCLUSIONS: The authors have demonstrated that high-quality MR images can be obtained in the operating room within reasonable time constraints. Procedures can be conducted without compromising or altering traditional neurosurgical, nursing, or anesthetic techniques. It is feasible that within the next decade intraoperative MR imaging may become the standard of care in neurosurgery.

Adult↗
PubMed1999

Advances in spinal cord regeneration.

Spinal cord injury continues to be a major cause of morbidity, particularly among young people involved in vehicle-related trauma, falls, and sports injuries. Although research advances are still a long way from clinical treatments, recent studies on animals have indicated new possibilities for recovery of function. In this review, these new findings on the use of neurotrophic factors, antibodies to inhibitory molecules, electrical stimulation, and transplantation of peripheral nerves and olfactory glial cells, and their success in achieving functional recovery after adult spinal cord lesions are discussed.

Adult↗
PubMed2002

Pharmacological, cell, and gene therapy strategies to promote spinal cord regeneration.

In this review, recent studies using pharmacological treatment, cell transplantation, and gene therapy to promote regeneration of the injured spinal cord in animal models will be summarized. Pharmacological and cell transplantation treatments generally revealed some degree of effect on the regeneration of the injured ascending and descending tracts, but further improvements to achieve a more significant functional recovery are necessary. The use of gene therapy to promote repair of the injured nervous system is a relatively new concept. It is based on the development of methods for delivering therapeutic genes to neurons, glia cells, or nonneural cells. Direct in vivo gene transfer or gene transfer in combination with (neuro)transplantation (ex vivo gene transfer) appeared powerful strategies to promote neuronal survival and axonal regrowth following traumatic injury to the central nervous system. Recent advances in understanding the cellular and molecular mechanisms that govern neuronal survival and neurite outgrowth have enabled the design of experiments aimed at viral vector-mediated transfer of genes encoding neurotrophic factors, growth-associated proteins, cell adhesion molecules, and antiapoptotic genes. Central to the success of these approaches was the development of efficient, nontoxic vectors for gene delivery and the acquirement of the appropriate (genetically modified) cells for neurotransplantation. Direct gene transfer in the nervous system was first achieved with herpes viral and El-deleted adenoviral vectors. Both vector systems are problematic in that these vectors elicit immunogenic and cytotoxic responses. Adeno-associated viral vectors and lentiviral vectors constitute improved gene delivery systems and are beginning to be applied in neuroregeneration research of the spinal cord. Ex vivo approaches were initially based on the implantation of genetically modified fibroblasts. More recently, transduced Schwann cells, genetically modified pieces of peripheral nerve, and olfactory ensheathing glia have been used as implants into the injured spinal cord.

Animals↗
PubMed1992

Characteristic distribution of glycolipids in gadoid fish nerve tissues and its bearing on phylogeny.

Glycolipids were isolated from nerve tissues of gadoid fishes including Alaskan pollack and Pacific cod. Their chemical structures were determined by gas-liquid chromatography and gas chromatography-mass spectrometry, and their constituents were analyzed in detail and compared with those of glycolipids from other fish groups. The results revealed that gadoid fish nerve membranes contain peculiar glycolipid molecular species that are distinctly different from those in other teleostean fishes and higher vertebrates. The mole percentage ratio of the four major glycolipids (cerebroside-sulfatide-galactosylglyceride-sulfogalactosylglyce ride) was 48:12:25:15, indicating profound accumulation of glycoglycerolipids. Galactosylglyceride and sulfogalactosylglyceride were primarily of the diacyl type (greater than 90%), the major fatty acids being 16:0 and 18:1. An abundance of glucocerebroside (25 to 55% of cerebroside) and its fatty acid ester (37 to 47% of ester cerebroside) was noted. Cerebroside and sulfatide were characterized by the absence of hydroxy and odd numbered fatty acids, and 24:1 acid was a predominant component of both glucocerebroside and galactocerebroside. Subcellular fractionation revealed that myelin membranes comprised such unusual glycolipid constituents as those seen in whole nerve tissues. A vertebrate whose nerve membranes consist of such peculiar glycolipid molecules has not previously been reported. The characteristics of the glycolipid composition in gadoid fishes are discussed in relation to myelin functions, physicochemical properties of nerve membranes, and the phylogenic significance of this fish group.

Animals↗
PubMed1990

Autonomic regulation of cutaneous vascular resistance in the bullfrog Rana catesbeiana.

To gain a better understanding of the regulation of cutaneous blood flow in the bullfrog, the vascular innervation, vasoactivity and adrenoceptor types of the cutaneous vasculature were investigated using a pump-perfused skin preparation. Stimulation of cranial nerve I, the vagal ganglion, sympathetic ganglion 1 and sometimes sympathetic ganglion 2 caused cutaneous vascular resistance (CVR) to increase. Stimulation of cranial nerve IX and spinal nerves 1 and 2 had no effect on CVR. The response to stimulation of sympathetic ganglion 1 was antagonized by phentolamine but not by atropine. Phentolamine, atropine and alpha,beta-methylene ATP had no effect on the response to vagal stimulation. Both epinephrine (EPI) and norepinephrine (NE) increased CVR, with EPI being more potent than NE. The minimum concentrations of EPI and NE required for a significant change in CVR were much higher than plasma catecholamine levels reported for resting bullfrogs. Phentolamine antagonized, but propranolol had no effect on, the responses to the catecholamines. Isoproterenol caused small decreases in CVR which were abolished by propranolol. Acetylcholine was a weak vasodilator. The results indicate that the cutaneous vasculature has two types of vasomotor nerves: sympathetic nerves that are probably adrenergic, and other nerves that are non-adrenergic/non-cholinergic and which do not use ATP as a transmitter. Although catecholamines are vasoactive, the sensitivity of the cutaneous vasculature to EPI and NE is probably too low to allow a direct regulatory role of these hormones on CVR. There is no evidence for cholinergic regulation of CVR. Both alpha- and beta-adrenoceptors are present in the cutaneous vasculature. alpha-Adrenoceptors mediate the constrictor responses to sympathetic nerve stimulation and catecholamine administration. It is unlikely that beta-adrenoceptors play a significant role in regulating CVR.

Acetylcholine↗
PubMed1972

Electric-field-induced shifts in the infrared spectrum of conducting nerve axons.

Difference spectra between resting and excited nerve in the infrared region between 2000 and 1000 cm(-1) have been examined with a resolution of 0.5 cm(-1). Spectra were obtained with a modified Perkin-Elmer model 521 grating infrared spectrophotometer (Perkin-Elmer Corp., Instrument Div., Norwalk, Conn.), and the signal-to-noise (S/N) ratio was improved by time averaging and digital smoothing. Peaks occurring in the regions around 1030 and 1066 cm(-1) are identified as P-O-C stretch, at 1410-1414 cm(-1) as C-H deformation, and at 1750 cm(-1) as carbonyl stretch. The difference peaks appear to be due to a shift of about 1 cm(-1) in the absorption band to lower frequencies for the three lower frequency bands and to a higher frequency for 1750 cm(-1) band. Since the difference peaks appear when the nerve is modulated by a propagated action potential it is concluded that the changing electrical field across the nerve membrane is perturbing the absorption spectrum. From evidence presented it appears likely that these difference peaks are due to phospholipids in the nerve membrane and that they may be related to conformational changes associated with membrane permeability.

Animals↗
PubMed2001

A subpopulation of nervus terminalis neurons projects to the olfactory mucosa in Xenopus laevis.

Biocytin application to the normal or zinc sulfate-treated nasal cavity of Xenopus laevis was used to trace retrogradely neurons associated with the terminal nerve (TN). Immunocytochemistry was conducted to identify the relationship of gonadotropin-releasing hormone-immunoreactive (GnRH-ir) TN neurons with biocytin-labeled neurons. Neurons that accumulated biocytin were located in olfactory nerve fascicles close to the olfactory mucosa lining the caudal, medial, and rostral walls of the principal cavity. GnRH-ir fibers were observed only in the olfactory nerve fascicle projecting to the rostral edge of the principal cavity. In addition, GnRH-ir fibers did not contact biocytin-labeled TN neurons. We hypothesize that these two classes of neurons represent separate components of the TN.

Animals↗
PubMed1985

Postnatal development of brain alpha 1-adrenergic receptors: in vitro autoradiography with [125I]HEAT in normal rats and rats treated with alpha-difluoromethylornithine, a specific, irreversible inhibitor of ornithine decarboxylase.

The postnatal development of brain alpha 1-adrenergic receptors was studied in the rat brain using in vitro autoradiography. In some regions, such as the globus pallidus, receptor-binding sites were present at birth and increased during the first week but then decreased to very low levels by adulthood. In contrast, other regions such as the olfactory bulb and cerebral cortex exhibited little binding at birth, with a subsequent increase in receptors during the second week of life that persisted into the mature stage. Several regions had an intermediate pattern with significant labelling at birth, an increase in the first few weeks and a smaller decrement in binding sites as adulthood was approached. The data suggested that there were two archetypal development patterns, one of which was potentially related to the arrival of noradrenergic nerve projections (olfactory bulb) and the other of which was determined intrinsically by differentiation (globus pallidus). The two patterns could be distinguished by their sensitivity to alpha-difluoromethylornithine, a drug that inhibits ornithine decarboxylase, leading to a slowing of cellular replication, differentiation and migration. Drug treatment dramatically delayed the developmental fall-off of binding in the globus pallidus such that receptor sites remained in high concentration well past the point at which they disappeared in control animals. In the olfactory bulb, however, alpha-difluoromethylornithine had little or no effect on the ontogeny of receptor binding. These studies provide evidence that alpha 1-adrenergic receptors in various brain regions develop at different rates and with at least two characteristic patterns. Autoradiographic techniques provide important insights into receptor development that cannot be garnered from biochemical methods using isolated membrane preparations.

Adrenergic alpha-Antagonists↗