Search results for "Olfactory Nerve"
showing 8 items of 18 documents
Synaptogenesis in the mouse olfactory bulb during glomerulus development
2008
Synaptogenesis is essential for the development of neuronal networks in the brain. In the olfactory bulb (OB) glomeruli, numerous synapses must form between sensory olfactory neurons and the dendrites of mitral/tufted and periglomerular cells. Glomeruli develop from E13 to E16 in the mouse, coincident with an increment of the neuropil in the border between the external plexiform (EPL) and olfactory nerve layers (ONL), coupled to an extensive labelling of phalloidin and GAP-43 from the ONL to EPL. We have tracked synaptogenesis in the OB during this period by electron microscopy (EM) and immunolabelling of the transmembrane synaptic vesicle glycoprotein SV-2. No SV-2 labelling or synapses we…
Bilateral olfactory deprivation reveals a selective noradrenergic regulatory input to the olfactory bulb.
2001
Unilateral olfactory deprivation in the rat induces changes in the catecholaminergic system of the olfactory bulb. Nevertheless, evidence suggests that unilateral deprivation does not fully prevent stimulation of the deprived bulb. The present report analyses the response of the catecholaminergic system of the olfactory bulb in fully deprived rats obtained by bilateral naris occlusion. The complete deprivation produces more rapid and dramatic changes in both the intrinsic and extrinsic catecholaminergic systems of the olfactory bulb. Intrinsic responses involve a rapid decrease in dopamine-containing cells to about 25% of controls, correlated with a decreased Fos expression in juxtaglomerul…
Types of cholecystokinin-containing periglomerular cells in the mouse olfactory bulb
2010
The periglomerular cells (PG) of the olfactory bulb (OB) are involved in the primary processing and the refinement of sensory information from the olfactory epithelium. The neurochemical composition of these neurons has been studied in depth in many species, and over the last decades such studies have focused mainly on the rat. The increasing use of genetic models for research into olfactory function demands a profound characterization of the mouse olfactory bulb, including the chemical composition of bulbar interneurons. Regarding both their connectivity with the olfactory nerve and their neurochemical fate, recently, two different types of PG have been identfied in the mouse. In the prese…
Nitric oxide synthase containing periglomerular cells are GABAergic in the rat olfactory bulb.
2003
In the olfactory glomeruli of the rat olfactory bulb, there is a population of periglomerular cells (PG) that contains the neuronal isoform of the nitric oxide synthase (nNOS). To date, these PG have not been characterized neurochemically and it has not been determined whether they are type 1 (GABAergic PG that receive synaptic contacts from the olfactory axons) or type 2 PG (non-GABAergic PG that do not receive synapses from the olfactory axons). Combining pre-embedding NADPH-diaphorase histochemistry and post-embedding immunoperoxidase detection of GABA, we demonstrate that nNOS-containing PG are GABAergic and therefore, belong to the type 1 PG. The possible actions of nitric oxide in the…
Subcellular localization of m2 muscarinic receptors in GABAergic interneurons of the olfactory bulb
2000
We analysed the ultrastructural distribution of the m2 muscarinic receptor (m2R) in the rat olfactory bulb (OB) using immunohistochemical techniques and light and electron microscopy. m2R was differentially distributed within the cellular compartments of gamma-aminobutyric acid (GABA)ergic bulbar interneurons. It is located in the gemmules of granule cells and in the synaptic loci of the interneurons of the external plexiform layer, suggesting that m2R activation could modulate the release of GABA from these interneurons onto principal cells by a presynaptic mechanism. By contrast, the receptor appears in the somata and dendritic trunks of second-order short-axon interneurons located in the…
Distribution of D2 dopamine receptor in the olfactory glomeruli of the rat olfactory bulb
2005
Dopamine plays key roles in the processing of the olfactory information that takes place in the olfactory glomeruli. Previous studies using autoradiography demonstrate that, at the glomerular level, these actions are mainly mediated via activation of D2 dopamine receptors. Moreover, it has been suggested that D2 receptors could be present in the olfactory nerve, where they might modulate the entrance of olfactory input into the brain. Nevertheless, the precise subcellular localization of D2 receptors in the glomerular neuropil has not been investigated. In this report, we show the subcellular distribution of D2 receptors in the glomerular circuits of Wistar rats, using pre-embedding immunog…
Chemoresponsiveness and Breath Physiology in Anosmia
2014
Anosmia is a model to study the interaction among chemoreception systems. In the head injury, the traumatic irreversible anosmia caused by damage to olfactory nerve fibers and brain regions is of enviable research interest. In this study, psychophysiological tests for a comprehensive assessment of olfactory function were utilized to investigate anosmia, together with a new technique based on the breath real-time monitoring of volatile organic compounds (VOCs). We applied the breath and VOCs analysis to investigate chemoresponsiveness in the long-term irreversible post-traumatic anosmia.
Objective measures of nasal function
1995
Numerous techniques to objectively measure nasal function are available to the rhinologic surgeon. Rhinomanometry, acoustic rhinometry, laser Doppler flowmetry, saccharin transport time, determination of ciliary beat frequency, and olfactory and trigeminal event-related potentials are all techniques in current use. Rhinomanometry is the standard clinical tool used to indicate those patients complaining of nasal obstruction who are likely to benefit from septal and turbinate surgery. Acoustic rhinometry permits the precise localization of nasal stenoses and is the best predictor of a patient's postoperative satisfaction. It is, in addition, more sensitive than rhinomanometry in recording cha…