Search results for "Amygdala"
showing 10 items of 169 documents
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…
Chemosensory Function of the Amygdala
2010
The chemosensory amygdala has been traditionally divided into two divisions based on inputs from the main (olfactory amygdala) or accessory (vomeronasal amygdala) olfactory bulbs, supposedly playing different and independent functional roles detecting odors and pheromones, respectively. Recently, there has been increased anatomical evidence of convergence inputs from the main and accessory bulbs in some areas of the amygdala, and this is correlated with functional evidence of interrelationships between the olfactory and the vomeronasal systems. This has lead to the characterization of a third division of the chemosensory amygdala, the mixed chemosensory amygdala, providing a new perspective…
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…
Fiber Connections of the Amygdaloid Formation of the Lizard <i>Podarcis hispanica</i>
1993
The amygdaloid formation of the lizard Podarcis hispanica can be divided into three main groups of nuclei on the basis of their input from the main and accessory olfactory bulbs: the vomeronasal amygdala, the olfactory amygdala and the dorsal amygdaloid group, the latter group receiving afferents from neither the main (MOB) or the accessory olfactory bulb (AOB). The vomeronasal amygdala has a centrifugal projection to the AOB, an important commissural connection to the contralateral vomeronasal amygdala, a minor projection to nucleus accumbens, and a bilateral projection to the lateral cortex. The olfactory amygdala displays a bilateral afferents from the MOB, receives a contralateral affer…
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 …
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…
Gadd45α modulates aversive learning through post‐transcriptional regulation of memory‐related mRNA s
2018
Abstract Learning is essential for survival and is controlled by complex molecular mechanisms including regulation of newly synthesized mRNAs that are required to modify synaptic functions. Despite the well‐known role of RNA‐binding proteins (RBPs) in mRNA functionality, their detailed regulation during memory consolidation is poorly understood. This study focuses on the brain function of the RBP Gadd45α (growth arrest and DNA damage‐inducible protein 45 alpha, encoded by the Gadd45a gene). Here, we find that hippocampal memory and long‐term potentiation are strongly impaired in Gadd45a‐deficient mice, a phenotype accompanied by reduced levels of memory‐related mRNAs. The majority of the Ga…
Severity of dependence modulates smokers' neuronal cue reactivity and cigarette craving elicited by tobacco advertisement
2010
Smoking-related cues elicit craving and mesocorticolimbic brain activation in smokers. Severity of nicotine dependence seems to moderate cue reactivity, but the direction and mechanisms of its influence remains unclear. Although tobacco control policies demand a ban on tobacco advertising, cue reactivity studies in smokers so far have not employed tobacco advertisement as experimental stimuli. We investigated whether tobacco advertisement elicits cue reactivity at a behavioral (subjective craving) and a neural level (using functional magnetic resonance imaging) in 22 smokers and 21 never-smokers. Moreover, we studied the influence of severity of dependence on cue reactivity. In smokers, tob…
The control of amygdaloid and temporal paroxysmal activity by the caudate nucleus
1971
In gatti curarizzati ed in gatti portatori di elettrodi a dimora e liberi di muoversi, la stimolazione ripetitiva ad alta frequenza del nucleo caudato inibisce la comparsa sia dei fenomeni bioelettrici parossistici focalizzati nell'amigdala e nella corteccia temporale sia dei fenomeni comportamentali omologabili all'epilessia psicomotoria.