Search results for "Tubercle"
showing 10 items of 33 documents
Piriform Cortex and Amygdala
2012
Publisher Summary A ventral view of the cerebral hemispheres of mammals shows an array of structures ultimately connected with the olfactory bulbs through the olfactory tracts. This is the basis for the old concept of rhinencephalon, a series of neural centers in the cerebral hemispheres, located ventral to the rhinal fissure, for which an olfactory role was assumed. Although mice lack a conspicuous rhinal fissure, their “rhinencephalon” is well developed. The concept of the rhinencephalon is difficult to sustain nowadays, as it includes neural centers of diverse origin, organization and nature. The rhinencephalon comprises several allocortical areas that constitute the olfactory cortex, de…
Hypothalamus-olfactory system crosstalk: orexin a immunostaining in mice
2012
It is well known that olfaction influences food intake, and conversely, that an individual’s nutritional status modulates olfactory sensitivity. However, what is still poorly understood is the neuronal correlate of this relationship, as well as the connections between the olfactory bulb and the hypothalamus. The goal of this report is to analyze the relationship between the olfactory bulb and hypothalamus, focusing on orexin A immunostaining, a hypothalamic neuropeptide that is thought to play a role in states of sleep/wakefulness. Interestingly, orexin A has also been described as a food intake stimulator. Such an effect may be due in part to the stimulation of the olfactory bulbar pathway…
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…
Tibial tubercle osteotomy: effect of different osteotomy planes on contact surface area and tubercle anteriorization
2022
In 1983, Fulkerson introduced a technique of tibial tubercle osteotomy performed according to an inclined plane with respect to frontal plane. Due to obliquity of the osteotomy plane, this procedure allows both anterior and medial transfer of the tibial tubercle. The purpose of the study was to investigate the influence of the different degrees of the oblique plane of osteotomy on anterior displacement and the contact surface area of tibial tubercle. Synthetic bones were used for the study. An osteotomy of the tibial tubercle (TT) was performed in each specimen. Specifically, 3 different degrees of osteotomy planes relative to the reference frontal plane were examined: 20°, 30° and 40°. On …
Spontaneous fracture of the mandibular genial tubercles: A case report
2007
Fracture of the mandibular genial tubercles is an uncommon pathology affecting edentulous patients with severe maxillary atrophy. Usually occurs spontaneously which complicates the diagnosis. Their importance lies in the functional alterations, which occur as a consequence of the disinsertion of the genihyoid and genioglossus muscles. The treatment of fracture of the genial tubercles is controversial, including no surgical intervention, excision of the avulsed bone fragments, and muscular repositioning. There have been only 11 cases reported in the literature of this fracture, most of them spontaneous. We present a difficult diagnosis situation of spontaneous fracture of the genial tubercle…
Hierarchical cross-scale analysis identifies parallel ventral striatal networks coding for dynamic and stabilized olfactory reward predictions
2021
SUMMARYThe unbiased identification of brain circuits responsible for behavior and their local cellular computations is a challenge for neuroscience. We establish here a hierarchical cross-scale approach from behavioral modeling and fMRI in task-performing mice to cellular network dynamics to identify how reward predictions are represented in the forebrain upon olfactory conditioning. fMRI identified functional segregation in reward prediction and error computations among olfactory cortices and subcortical circuits. Among them, the olfactory tubercle contributed both to dynamic reward predictions and prediction error. In this region, cellular recordings revealed two parallel neuronal populat…
Olfactory and cortical projections to bulbar and hippocampal adult-born neurons
2015
New neurons are continually generated in the subependymal layer of the lateral ventricles and the subgranular zone of dentate gyrus during adulthood. In the subventricular zone, neuroblasts migrate a long distance to the olfactory bulb where they differentiate into granule or periglomerular interneurons. In the hippocampus, neuroblasts migrate a short distance from the subgranular zone to the granule cell layer of the dentate gyrus to become granule neurons. In addition to the short-distance inputs, bulbar interneurons receive long-distance centrifugal afferents from olfactory-recipient structures. Similarly, dentate granule cells receive differential inputs from the medial and lateral ento…
Induction of c-fos gene expression by the selective sigma receptor ligand EMD 57445 in rat brain.
1996
Based on animal studies it has been reasoned that ligands to sigma binding sites might be effective in the treatment of schizophrenic disorders and may also be used to investigate this largely elusive disorder on a molecular level. Expression patterns of c-fos in rat brain were studied following treatment with single doses of the sigma ligand EMD 57445 (0.3, 1, 3, 30 mg/kg s.c.). Specific c-fos gene expression was detected at all concentrations tested in various cortical areas. The signals observed were dose-dependent with the highest intensities in the piriform cortex. Strong signals were also detected in hippocampal areas CA 1,2,3 and the gyrus dentatus, as well as in the medial habenula …
Regulation of NT Receptors after Chronic Treatment with Typical and Atypical Neuroleptic Drugs
1991
Neurotensin is a tridecapeptide, which produces central effects such as hypotension, hypothermia, muscle relaxation, analgesia, antinociception, and reduces locomotor activity (Nemeroff et al., 1977). In the recent years, several lines of evidences indicated the great importance of the dopamine (DA)- neurotensin (NT) interaction taking place mostly in the mesolimbocortical areas, both at cell bodies (A10 DA-ergic group located in the ventral tegmental area -VTA-) and nerve terminal level (cerebral cortex, n. accumbens, olfactory tubercle, ventral n. caudato-putamen) (Quirion, 1983; Nemeroff, et al., 1984; Nemeroff, 1986). Immunocytochemical data indicated the presence of NT-like immunoreact…