Search results for "Tubercle"
showing 10 items of 33 documents
Effect of sertraline treatment on benzodiazepine receptors in the rat brain.
1993
In this paper we describe the modification of benzodiazepine (BDZ) binding sites in the rat brain after different times of treatment with the 5-hydroxytryptamine-(5HT) uptake blocker sertraline. We investigated the effect of 8, 15 and 30 days sertraline treatment (10 mg/kg/day, i.p.) on 3 H-flunitrazepam binding sites. In order to describe the anatomical site of action of the drug, the experiment has been carried out by means of quantitative receptor autoradiography. After 8 days of sertraline treatment, an increase of BDZ receptor density is found in the olfactory tubercle. This effect is reversed at 15 and 30 days. At 15 days of treatment, an increase is found in the anterior cingulate co…
Afferent and efferent connections of the olfactory bulbs in the lizard Podarcis hispanica.
1991
The connections of the olfactory bulbs of Podarcis hispanica were studied by tract-tracing of injected horseradish peroxidase. Restricted injections into the main olfactory bulb (MOB) resulted in bilateral terminallike labeling in the medial part of the anterior olfactory nucleus (AON) and in the rostral septum, lateral cortex, nucleus of the lateral olfactory tract, and ventrolateral amygdaloid nucleus. Bilateral retrograde labeling was found in the rostral lateral cortex and in the medial and dorsolateral AON. Ipsilaterally the dorsal cortex, nucleus of the diagonal band, lateral preoptic area, and dorsolateral amygdala showed labeled cell bodies. Retrogradely labeled cells were also foun…
Neural substrates for processing chemosensory information in snakes.
2002
Snakes interact with their chemical environment through their olfactory and vomeronasal systems. The present report summarizes advances on neural substrates for processing chemosensory information. First, the efferent and centrifugal afferent connections of the main and accessory olfactory bulbs were reinvestigated. Second, the afferent and efferent connections of the nucleus sphericus, the main target of the accessory olfactory bulb, were characterized. The nucleus sphericus gives rise to a very small projection to the hypothalamus, but it does project to other telencephalic structures where olfactory and vomeronasal information could converge. Third, the intra-amygdaloid circuitry and the…
Projections from the posterolateral olfactory amygdala to the ventral striatum: neural basis for reinforcing properties of chemical stimuli
2007
Abstract Background Vertebrates sense chemical stimuli through the olfactory receptor neurons whose axons project to the main olfactory bulb. The main projections of the olfactory bulb are directed to the olfactory cortex and olfactory amygdala (the anterior and posterolateral cortical amygdalae). The posterolateral cortical amygdaloid nucleus mainly projects to other amygdaloid nuclei; other seemingly minor outputs are directed to the ventral striatum, in particular to the olfactory tubercle and the islands of Calleja. Results Although the olfactory projections have been previously described in the literature, injection of dextran-amines into the rat main olfactory bulb was performed with …
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…
Focal Lesions within the ventral striato-pallidum abolish attraction for male chemosignals in female mice
2014
In rodents, socio-sexual behaviour is largely mediated by chemosensory cues, some of which are rewarding stimuli. Female mice display an innate attraction towards male chemosignals, dependent on the vomeronasal system. This behaviour likely reflects the hedonic value of sexual chemosignals. The anteromedial aspect of the olfactory tubercle, along with its associated islands of Calleja, receives vomeronasal inputs and sexually-dimorphic vasopressinergic innervation. Thus, we hypothesised that this portion of the ventral striato-pallidum, known to be involved in reward processing, might be important for sexual odorant-guided behaviours. In this study, we demonstrate that lesions of this regio…
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…
The vomeronasal cortex - afferent and efferent projections of the posteromedial cortical nucleus of the amygdala in mice
2013
Most mammals possess a vomeronasal system that detects predominantly chemical signals of biological relevance. Vomeronasal information is relayed to the accessory olfactory bulb (AOB), whose unique cortical target is the posteromedial cortical nucleus of the amygdala. This cortical structure should therefore be considered the primary vomeronasal cortex. In the present work, we describe the afferent and efferent connections of the posteromedial cortical nucleus of the amygdala in female mice, using anterograde (biotinylated dextranamines) and retrograde (Fluorogold) tracers, and zinc selenite as a tracer specific for zinc-enriched (putative glutamatergic) projections. The results show that t…
Sexual pheromones and the evolution of the reward system of the brain: the chemosensory function of the amygdala.
2008
The amygdala of all tetrapod vertebrates receives direct projections from the main and accessory olfactory bulbs, and the strong similarities in the organization of these projections suggest that they have undergone a very conservative evolution. However, current ideas about the function of the amygdala do not pay sufficient attention to its chemosensory role, but only view it as the core of the emotional brain. In this study, we propose that both roles of the amygdala are intimately linked since the amygdala is actually involved in mediating emotional responses to chemical signals. The amygdala is the only structure in the brain receiving pheromonal information directly from the accessory …