Search results for "ULB"
showing 10 items of 219 documents
3D atlas describing the ontogenic evolution of the primary olfactory projections in the olfactory bulb of Xenopus laevis.
2005
The adult Xenopus presents the unique capability to smell odors both in water and air thanks to two different olfactory pathways. Nevertheless, the tadpole can initially perceive only water-borne odorants, as the olfactory receptor neurons (ORN) that will detect air-borne odorants develop later. Such a phenomenon requires major reorganization processes. Here we focused on the precise description of the neuroanatomical modifications occurring in the olfactory bulb (OB) of the tadpole throughout metamorphosis. Using both carbocyanine dyes and lectin staining, we investigated the evolution of ORN projection patterns into the OB from Stages 47 to 66, thus covering the period of time when all th…
Synaptic connectivity of serotonergic axons in the olfactory glomeruli of the rat olfactory bulb.
2010
Although the major mode of transmission for serotonin in the brain is volume transmission, previous anatomical studies have demonstrated that serotonergic axons do form synaptic contacts. The olfactory glomeruli of the olfactory bulb of mammals receive a strong serotonergic innervation from the dorsal and medial raphe nuclei. In the present report, we investigate the synaptic connectivity of these serotonergic axons in the glomerular neuropil of the rat olfactory bulb. Our study shows that serotonergic axons form asymmetrical synaptic contacts on dendrites within the glomerular neuropil. Analyzing the neurochemical nature of the synaptic targets, we have found that 55% of the synapses were …
Segregated pathways to the vomeronasal amygdala: differential projections from the anterior and posterior divisions of the accessory olfactory bulb.
2007
Apically and basally located receptor neurons in the vomeronasal sensory epithelium express G(i2 alpha)- and G(o alpha)-proteins, V1R and V2R vomeronasal receptors, project to the anterior and posterior accessory olfactory bulb and respond to different stimuli, respectively. The extent to which secondary projections from the two portions of the accessory olfactory bulb are convergent in the vomeronasal amygdala is controversial. This issue is addressed by using anterograde and retrograde tract-tracing methods in rats including electron microscopy. Injections of dextran-amines, Fluoro Gold, cholera toxin-B subunit and Fast Blue were delivered to the anterior and posterior accessory olfactory…
Organization of the ophidian amygdala: chemosensory pathways to the hypothalamus.
1999
Although recent studies in squamate reptiles have importantly clarified how chemical information is processed in the reptilian brain, how the amygdala relays chemosensory inputs to the hypothalamus to influence chemically guided behaviors is still poorly documented. To identify these chemosensory pathways, the amygdalo-hypothalamic projections, intra-amygdaloid circuitry and afferents from the lateral cortex (LC) to the amygdala were investigated by injecting conjugated dextran-amines into the hypothalamus, amygdala, and LC of garter snakes. The amygdala was divided into olfactory recipient (ventral anterior and external amygdalae), vomeronasal recipient (nucleus sphericus, NS, and medial a…
Role of the vomeronasal system in intersexual attraction in female mice
2008
Although it is generally accepted that rodents' sociosexual behavior relies mainly on chemosignals, the specific roles played by the vomeronasal and olfactory systems in detecting these signals are presently unclear. This work reports the results of three experiments aimed at clarifying the role of the vomeronasal system on gender recognition and intersexual attraction, by analyzing the effects of lesions of the accessory olfactory bulbs (AOB) in chemically naive female mice. The first experiment demonstrates that lesions of the AOB abolish the preference that females show for male-soiled bedding in tests in which the females can contact the bedding, thus having access to both volatile and …
Use of ultrasonic vocalizations to assess olfactory detection in mouse pups treated with 3-methylindole.
2005
International audience; Altricial mammals use olfaction long before the olfactory bulb has reached its anatomically mature state. Indeed, while audition and vision are still not functional, the olfactory system of newborn animals can clearly process distinct odorant molecules. Although several previous studies have emphasized the important role that olfaction plays in early critical functions, it has been difficult to develop a sensitive and reliable test to precisely quantify olfactory ability in pups. One difficulty in determining early sensory capabilities is the rather limited behavioral repertory of neonates. The present study examines the use of ultrasonic vocalizations emitted by iso…
Essential Oils and Pure Volatile Compounds as Potential Drugs in Alzheimer's Disease Therapy: An Updated Review of the Literature
2016
Background: The use of aromatic plants to relief different illness is not a new therapy. Actually aromatic plants have been used for many centuries by different cultures around the world. Pharmacological studies provide scientific support to the traditional use of aromatic medicinal plants and aromatherapy; nevertheless, more clinical trials are required regarding to their effectiveness in order to establish a guidance for their use in routine healthcare. Moreover, modern medicine in studies about olfactory function has attained great achievements and got Nobel Prize in 2004. These new searches have obviously fueled interest in the essential oils and volatile compounds of natural origin. Se…
Clinical application of adult olfactory bulb ensheathing glia for nervous system repair
2011
Abstract The ability of adult olfactory bulb ensheathing glia (OB-OEG) to promote histological and functional neural repair has been broadly documented. Pre-clinical studies show that beneficial effects of adult OB-OEG are repeatable in the same type of spinal cord injury initially tested, in other spinal cord and CNS injury models, in different species and after the administration of these cells in different forms (either alone or in combination with other cells, drugs, products or devices). These studies demonstrate the reproducibility, robustness, fundamental nature and relevance of the findings. Therefore, the use of adult OB-OEG for spinal cord injury repair meets the scientific criter…
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…