The terminalis nerve (TN) has been described in all vertebrate species, in which it plays important roles in animal behavior and physiology. In teleost fish, the TN is located in the olfactory bulb and in its nerve tract. Here, we report a study on the characterization of the TN cell ...

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 third paper by Camillo Golgi on his new method was on the olfactory bulb. This paper has never been translated into English, but is of special interest both for its pioneering description of olfactory bulb cells and for containing the first illustration by Golgi of cells stained with his ...

Nitric oxide (NO) is a free radical and produced from L-arginine by nitric oxide synthase (NOS). Since NO is recently suggested to be involved in olfactory perception, the expression of eNOS, an isoform of NOS, was examined in the rat olfactory epithelium. The activity of NADPH-diaphorase was also examined as ...

Olfactory dysfunction is a common symptom reported by patients with neurodegenerative disorders such as Alzheimer's and Parkinson's diseases. Despite the knowledge gathered about the pathology of these diseases, little information has been generated regarding the ultrastructure modifications of the granule cells that regulate the information for odor identification. Swollen organelles ...

Gonadotropin-releasing hormone (GnRH) is well known as a hypophysiotropic hormone that is produced in the hypothalamus and facilitates the release of gonadotropins from the pituitary gonadotropes. On the other hand, the functions of extrahypothalamic GnRH systems still remain elusive. Here we examined whether the activity of the olfactory bulbar neural ...

During development of the primary olfactory system, sensory axons project from the nasal cavity to the glomerular layer of the olfactory bulb. In the process axons can branch inappropriately into several glomeruli and sometimes over-shoot the glomerular layer, entering the deeper external plexiform layer. However in the adult, axons are ...

Olfactory ensheathing cells (OECs) constitute a unique population of glia that accompany and ensheath the primary olfactory axons. They are thought to be critical for spontaneous growth of olfactory axons within the developing and adult olfactory nervous system, and have recently emerged as potential candidates for cell-mediated repair of neural ...

Olfactory mucosa, the sense organ of smell, is an adult tissue that is regenerated and repaired throughout life to maintain the integrity of the sense of smell. When the sensory neurons of the olfactory epithelium die they are replaced by proliferation of stem cells and their axons grow from the ...

Olfactory acuity differs among animal species depending on age and dependence on smell. However, the attendant functional anatomy has not been elucidated. We sought to determine the functional structure of the olfactory mucosa in suckling and adult dog and sheep. Mucosal samples harvested from ethmoturbinates were analyzed qualitatively and quantitatively. ...

In this work we have analyzed the targets of the GABAergic afferents to the main olfactory bulb originating in the basal forebrain of the rat. We combined anterograde tracing of 10 kD biotinylated dextran amine (BDA) injected in the region of the horizontal limb of the diagonal band of Broca ...

Olfactory ensheathing cells (OECs) migrate with olfactory axons that extend from the nasal epithelium into the olfactory bulb. Unlike other glia, OECs are thought to migrate ahead of growing axons instead of following defined axonal paths. However it remains unknown how the presence of axons and OECs influences the growth ...

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 ...

The olfactory bulb receives a large number of centrifugal fibers whose functions remain unclear. To gain insight into the function of the bulbar centrifugal system, the morphology of individual centrifugal axons from olfactory cortical areas was examined in detail. An anterograde tracer, Phaseolus vulgaris leucoagglutinin, was injected into rat olfactory ...

Immunoreactivity of the calcium binging protein calretinin is often used as a marker of olfactory neurons. Although the immunoreactivity and density of olfactory neurons are known to change between developmental stages in the human fetus, previous descriptions have been limited to the olfactory epithelium and/or the nasal septum and have ...

The anterior olfactory nucleus (AON) occupies a crucial position within the olfactory circuit, as it is able to influence function in nearly every major synaptic processing stage of both the ipsilateral and the contralateral pathways. Nevertheless, very little is known about the region's internal organization and circuitry. The present study ...

The structural features of calbindin-positive neurons were studied in the mouse main olfactory bulb (MOB). Calbindin-positive neurons were heterogeneous, including numerous periglomerular cells, a few granule cells, small to medium-sized interneurons in the external plexiform layer, and large short-axon cells located in the external plexiform layer, internal plexiform layer, granule ...

Olfactory ensheathing cells (OECs) have been repeatedly implicated in mediating plasticity, particularly in situ in the olfactory nerve in which they support the extension of olfactory sensory neuron (OSN) axons from the olfactory epithelium to the olfactory bulb (OB). OECs are specialized glia whose processes surround OSN axon fascicles within ...

Olfactory ensheathing cells (OECs) are the glial cells that derive from the olfactory placode, envelop olfactory axons in the course of migration from the olfactory epithelium to the olfactory bulb and reside primarily in the olfactory nerve layer. OECs transplantation as a promising experimental therapy for axonal injuries has been ...

Hyposmia is an early symptom of idiopathic Parkinson's disease but the pathological bases of such dysfunction are largely unknown. The distribution of alpha-synuclein, which forms Lewy bodies and Lewy neurites, and the types of neurons (based on their neurotransmitters) affected by alpha-synucleinopathy were investigated in the olfactory system in Parkinson's ...

To determine the cytoplasmic morphological changes in the mitral cells and quantitative changes (number of mitral cells and thickness of mitral cell layer in microns) in the rat olfactory bulb after administration of propranolol. Experimental study. The Department of Anatomy, University of Health Sciences, Lahore, from January 2006 to January ...

NADPH-diaphorase (NADPH-d) staining of the bovine olfactory epithelium was compared with the immunohistochemical localization of nitric oxide synthase (NOS), soluble guanylyl cyclase, and cGMP (cyclic guanosine 3',5'-monophosphate). Out of the three isoforms, only the inducible NOS (NOS-II) was found at the epithelial surface correlating with the strong labelling for NADPH-d. ...

Chronic rhinosinusitis (CRS) is a complex heterogeneous inflammatory disease that affects the nasal cavity, but the pathological examination of the olfactory mucosa (OM) in this disease has been limited. Nasal biopsy specimens were obtained from 20 control subjects and 50 CRS patients in conjunction with clinical assessments. Histopathology of these ...

Local inhibitory circuits are thought to shape neuronal information processing in the central nervous system, but it remains unclear how specific properties of inhibitory neuronal interactions translate into behavioral performance. In the olfactory bulb, inhibition of mitral/tufted cells via granule cells may contribute to odor discrimination behavior by refining neuronal ...

In this issue of Neuron, Abraham et al. report a direct connection between inhibitory function and olfactory behavior. Using molecular methods to alter glutamate receptor subunit composition in olfactory bulb granule cells, the authors found a selective modulation in the time required for difficult, but not simple, olfactory discrimination tasks.

Synchronization of 30-80 Hz oscillatory activity of the principle neurons in the olfactory bulb (mitral cells) is believed to be important for odor discrimination. Previous theoretical studies of these fast rhythms in other brain areas have proposed that principle neuron synchrony can be mediated by short-latency, rapidly decaying inhibition. This ...

The histological and micro-architecture of different cells lining the olfactory epithelium in Catla catla (Hamilton) have been studied by means of light and scanning electron microscopes. The oval olfactory rosette of the fish consists of a rosette of 30 to 32 primary lamellae. Each lamella is provided with restricted area ...

We investigated adult neurogenesis in two species of mammals belonging to the superorder Laurasiatheria, the southern white-breasted hedgehog (order Erinaceomorpha, species Erinaceus concolor) from Armenia and the European mole (order Soricomorpha, species Talpa europaea) from Poland. Neurogenesis in the brain of these species was examined immunohistochemically, using the endogenous markers ...

The Mt. Desert Island Biological Laboratory (MDIBL) has played a central role in the study of fish osmoregulation for the past 80 years. In particular, scientists at the MDIBL have made significant discoveries in the basic pattern of fish osmoregulation, the function of aglomerular kidneys and proximal tubular secretion, the roles ...

Species-specific characteristics of neuronal plasticity emerging from comparative studies can address the functional relevance of hippocampal or cortical plasticity in the light of ecological adaptation and evolutionary history of a given species. Here, we present a quantitative and qualitative analysis of neurogenesis in young and adult free-living Wahlberg's epauletted fruit ...

In acipenserids, crypt cells (CCs) have only been observed in juvenile specimens, and it has not been clarified whether they differentiate along with olfactory receptor neurons (ORNs) during the lecithotrophic stage or during later development stages. Furthermore, no detailed optical microscopy (OM) or electron microscopy study on the development of ...

Neurogranin (Ng) is a brain-specific postsynaptic protein involved in activity-dependent synaptic plasticity through modulation of Ca(2+)/calmodulin (CaM)-dependent signal transduction in neurons. In this study, using biochemical and immunohistochemical approaches, we demonstrate Ng expression in the adult mouse olfactory bulb (OB), the first relay station in odor information processing. We show ...

New olfactory bulb granule cells (GCs) are GABAergic interneurons continuously arising from neuronal progenitors and integrating into preexisting bulbar circuits. They receive both GABAergic and glutamatergic synaptic inputs from olfactory bulb intrinsic neurons and centrifugal afferents. Here, we investigated the spatiotemporal dynamic of newborn GC synaptogenesis in adult mouse olfactory ...

The immunoreactivity and protein expression of olfactory marker protein (OMP) and tyrosine hydroxylase (TH) in the main olfactory bulb (MOB) of the dog during normal ageing was investigated. OMP immunolabelling was observed only in nerve bundles of the olfactory nerve (ONL) and glomerular layers (GL) and there was no OMP ...

The effect of manganese toxicity on the ultrastructure of the olfactory bulb was evaluated. Male albino mice were injected intraperitoneally with MnCl2 (5 mg/Kg/day) five days per week during nine weeks. The control group received NaCl (0.9%). The olfactory bulbs of five mice from each group were processed for transmission ...

Several lines of evidence have shown that the olfactory system of the fish contains the main and accessory olfactory systems. However, morphological data indicate that the accessory olfactory bulb, the primary centre for the accessory olfactory system, will not differentiate in the fish. Therefore, the fish olfactory bulb is supposed ...

With each sniff, the olfactory bulbs of the brain generate a neural activity pattern representing the odour environment, transmitting this to higher brain centres in the form of mitral cell output. Inhibitory circuits in the olfactory bulb glomerular and external plexiform layers may amplify contrast in these patterns, through surround ...

Studies of the tissues of the human olfactory mucosa have been performed to investigate olfactory dysfunction and, more recently, olfactory mucosa has attracted a novel interest of investigators because it can be used as an early marker of neurodegenerative conditions of the brain and as a source of multipotent neural ...

Previous studies from our laboratory reported that transplantation of a mixture of 50% p75+ olfactory ensheathing cells (OECs) and fibroblasts derived from the outer layers of the adult olfactory bulb into unilateral lesions of the rat corticospinal tract (CST) restore function in a directed fore-paw retrieval task and induce regeneration ...

Spontaneous and patterned activity, largely attributed to chemical transmission, shape the development of virtually all neural circuits. However, electrical transmission also has an important role in coordinated activity in the brain. In the olfactory bulb, gap junctions between apical dendrites of mitral cells increase excitability and synchronize firing within each ...

AIMS: Human olfactory epithelium becomes functional at birth, but prenatal development remains unclear. In the present study, we aimed to clarify the development of human olfactory epithelium using scanning electron microscopy (SEM). METHODS: The development of human olfactory epithelium was observed in 24 externally normal fetuses, which were formalin-fixed and ...

In the development of the olfactory system, olfactory receptor neurons (ORNs) project their axons from the olfactory epithelium (OE) to the olfactory bulb (OB). The surface of the OB is covered by the central nervous system (CNS) basal lamina. To establish this connection, pioneer axons of the ORNs penetrate the ...

Lipofuscin granules are generally considered as age-pigment. However, we encountered numerous large irregular clusters of lipofuscin granules in the olfactory nerve layer and glomerular layer of the main olfactory bulb (MOB) of young adult and even juvenile mice of C57BL/6J strain. Those numerous autofluorescent irregular lipofuscin granules were contained in ...

OBJECTIVE: To investigate the telencephalon developmental characteristics of Hynobius leehii, and enrich the research data of comparable neurobiology and nervous system development of amphibian. METHODS: HE staining and Nissl staining methods were used to study the telencephalon histological structure of Hynobius leechii at both the metamorphosis and the adult phases, ...

Inhibitory interneurons in the hippocampus and neocortex are differentiated into several morphological and functional subtypes that innervate distinct subcellular domains of principal neurons. In the olfactory bulb (OB), odor information is processed by local neuronal circuits that include the major inhibitory interneuron, granule cells (GCs). All GCs reported to date ...

Rnd proteins are a family of small GTPases that have been involved in axon path finding and CNS development by their control of actin cytoskeleton dynamics. Rnd proteins are constitutively activated and, subsequently, their functions determined by their localization and expression levels. In this work we have analyzed by Western ...

Decades of work in vivo and in vitro have provided a wealth of data on the properties of the reciprocal dendrodendritic synapses that connect olfactory bulb mitral and granule cells. However, hypotheses about the function of these connections have changed relatively little. These synapses are believed to mediate recurrent and ...

The impact of chronic rhinosinusitis (CRS) on the olfactory mucosa (OM) is dramatic. Cellular profiles and epithelial integrity in OM biopsies were evaluated using histological and immunohistochemical methods to define a strategy for future histological studies of CRS. We have examined nasal biopsies of 54 CRS patients (18-63 years old) ...

Olfactory sensory neuron (OSN) axons extend from the olfactory epithelium to the olfactory bulb without branching until they reach their target region, the glomerulus. In this report, we present evidence to support the involvement of sonic hedgehog in promoting rat olfactory sensory axons to branch and to enter into the ...

Cell alterations in the central nervous system are consistent consequences of early undernourishment. Because little is known about the effects of neonatal udernourishment upon the main olfactory bulb (OB) in Golgi-Cox stained material, we evaluated the total OB cross-sectional area, the area of individual OB layers, and the area of ...