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Foods (Basel, Switzerland) Aug 2021The anterior insula and rolandic operculum are key regions for flavour perception in the human brain; however, it is unclear how taste and congruent retronasal smell are...
The anterior insula and rolandic operculum are key regions for flavour perception in the human brain; however, it is unclear how taste and congruent retronasal smell are perceived as flavours. The multisensory integration required for sour flavour perception has rarely been studied; therefore, we investigated the brain responses to taste and smell in the sour flavour-processing network in 35 young healthy adults. We aimed to characterise the brain response to three stimulations applied in the oral cavity-sour taste, retronasal smell of mango, and combined flavour of both-using functional magnetic resonance imaging. Effective connectivity of the flavour-processing network and modulatory effect from taste and smell were analysed. Flavour stimulation activated middle insula and olfactory tubercle (primary taste and olfactory cortices, respectively); anterior insula and rolandic operculum, which are associated with multisensory integration; and ventrolateral prefrontal cortex, a secondary cortex for flavour perception. Dynamic causal modelling demonstrated that neural taste and smell signals were integrated at anterior insula and rolandic operculum. These findings elucidated how neural signals triggered by sour taste and smell presented in liquid form interact in the brain, which may underpin the neurobiology of food appreciation. Our study thus demonstrated the integration and synergy of taste and smell.
PubMed: 34574144
DOI: 10.3390/foods10092034 -
Frontiers in Aging Neuroscience 2022Normal aging causes profound changes of structural degeneration and glucose hypometabolism in the human brain, even in the absence of disease. In recent years, with the...
Normal aging causes profound changes of structural degeneration and glucose hypometabolism in the human brain, even in the absence of disease. In recent years, with the extensive exploration of the topological characteristics of the human brain, related studies in rats have begun to investigate. However, age-related alterations of topological properties in individual brain metabolic network of rats remain unknown. In this study, a total of 48 healthy female Sprague-Dawley (SD) rats were used, including 24 young rats and 24 aged rats. We used Jensen-Shannon Divergence Similarity Estimation (JSSE) method for constructing individual metabolic networks to explore age-related topological properties and rich-club organization changes. Compared with the young rats, the aged rats showed significantly decreased clustering coefficient () and local efficiency ( ) across the whole-brain metabolic network. In terms of changes in local network measures, degree () and nodal efficiency ( ) of left posterior dorsal hippocampus, and of left olfactory tubercle were higher in the aged rats than in the young rats. About the rich-club analysis, the existence of rich-club organization in individual brain metabolic networks of rats was demonstrated. In addition, our findings further confirmed that rich-club connections were susceptible to aging. Relative to the young rats, the overall strength of rich-club connections was significantly reduced in the aged rats, while the overall strength of feeder and local connections was significantly increased. These findings demonstrated the age-related reorganization principle of the brain structure and improved our understanding of brain alternations during aging.
PubMed: 35645769
DOI: 10.3389/fnagi.2022.895934 -
Scientific Reports Jan 2020Various neural systems cooperate in feeding behaviour, and olfaction plays crucial roles in detecting and evaluating food objects. While odour-mediated feeding behaviour...
Various neural systems cooperate in feeding behaviour, and olfaction plays crucial roles in detecting and evaluating food objects. While odour-mediated feeding behaviour is highly adaptive and influenced by metabolic state, hedonic cues and learning processes, the underlying mechanism is not well understood. Feeding behaviour is regulated by orexigenic and anorexigenic neuromodulatory molecules. However, knowledge of their roles especially in higher olfactory areas is limited. Given the potentiation of feeding behaviour in hunger state, we systemically examined the expression of feeding-related neuromodulatory molecules in food-restricted mice through quantitative PCR, in the olfactory bulb (OB), olfactory tubercle (OT), and remaining olfactory cortical area (OC). The OT was further divided into attraction-related anteromedial, aversion-related lateral and remaining central regions. Examination of 23 molecules including neuropeptides, opioids, cannabinoids, and their receptors as well as signalling molecules showed that they had different expression patterns, with many showing elevated expression in the OT, especially in the anteromedial and central OT. Further, in mice trained with odour-food association, the expression was significantly altered and the increase or decrease of a given molecule varied among areas. These results suggest that different olfactory areas are regulated separately by feeding-related molecules, which contributes to the adaptive regulation of feeding behaviour.
Topics: Animals; Blood Glucose; Feeding Behavior; Gene Expression Regulation; Insulin; Male; Mice, Inbred C57BL; Neurotransmitter Agents; Odorants; Olfactory Bulb; Olfactory Tubercle; Receptors, Neurotransmitter; Reward; Signal Transduction
PubMed: 31964903
DOI: 10.1038/s41598-020-57605-7 -
Brain and Behavior Dec 2023Since 2002, when we published our article about the anterior perforated substance (APS), the knowledge about the region has grown enormously.
INTRODUCTION
Since 2002, when we published our article about the anterior perforated substance (APS), the knowledge about the region has grown enormously.
OBJECTIVE
To make a better description of the anatomy of the zone with new dissection material added to the previous, to sustain the anatomical analysis of the MRI employing the SPACE sequence, interacting with our imagenology colleagues. Especially, we aim to identify and topographically localize by MRI the principal structures in APS-substantia innominata (SI).
METHOD
The presentation follows various steps: (1) location and boundaries of the zone and its neighboring areas; (2) schematic description of the region with simple outlines; (3) cursory revision of the SI and its three systems; (4) serial images of the dissections of the zone and its vessels, illustrated and completed when possible, by MRI images of a voluntary experimental subject (ES).
RESULTS
With this method, we could expose most of the structures of the region anatomically and imagenologically.
DISCUSSION
The zone can be approached for dissection with magnification and the habitual microsurgical instruments with satisfactory results. We think that fibers in this region should be followed by other anatomical methods in addition to tractography. The principal structures of ventral striopallidum and extended amygdala (EA) can be identified with the SPACE sequence. The amygdala and the basal ganglion of Meynert (BGM) are easily confused because of their similar signal. Anatomical clues can orient the clinician about the different clusters of the BGM in MRI.
CONCLUSIONS
The dissection requires a previous knowledge of the zone and a good amount of patience. The APS is a little space where concentrate essential vessels for the telencephalon, "en passage" or perforating, and neural structures of relevant functional import. From anatomical and MRI points of view, both neural and vascular structures follow a harmonious and topographically describable plan. The SPACE MRI sequence has proved to be a useful tool for identifying different structures in this area as the striatopallidal and EA. Anatomical knowledge of the fibers helps in the search of clusters of the basal ganglion.
Topics: Basal Ganglia; Substantia Innominata; Amygdala; Olfactory Tubercle; Basal Nucleus of Meynert
PubMed: 38010896
DOI: 10.1002/brb3.3029 -
PloS One 2015Neurons in the cerebral cortex stratify on the basis of their time of origin, axonal terminations and the molecular identities assigned during early development....
Neurons in the cerebral cortex stratify on the basis of their time of origin, axonal terminations and the molecular identities assigned during early development. Olfactory cortices share many feature with the neocortex, including clear lamination and similar cell types. The present study demonstrates that the markers differentially expressed in the projection neurons of the cerebral cortex are also found in olfactory areas. Three of the four regions examined (pars principalis of the anterior olfactory nucleus: AONpP, anterior and posterior piriform cortices: APC, PPC, and the olfactory tubercle) expressed transcription factors found in deep or superficial neurons in the developing neocortex, though large differences were found between areas. For example, while the AONpP, APC and PPC all broadly expressed the deep cortical marker CTIP2, NOR1 (NR4a3) levels were higher in AONpP and DAARP-32 was more prevalent in the APC and PPC. Similar findings were encountered for superficial cortical markers: all three regions broadly expressed CUX1, but CART was only observed in the APC and PPC. Furthermore, regional variations were observed even within single structures (e.g., NOR1 was found primarily in in the dorsal region of AONpP and CART expression was observed in a discrete band in the middle of layer 2 of both the APC and PPC). Experiments using the mitotic marker EDU verified that the olfactory cortices and neocortex share similar patterns of neuronal production: olfactory cells that express markers found in the deep neocortex are produced earlier than those that express superficial makers. Projection neurons were filled by retrograde tracers injected into the olfactory bulb to see if olfactory neurons with deep and superficial markers had different axonal targets. Unlike the cerebral cortex, no specificity was observed: neurons with each of the transcription factors examined were found to be labelled. Together the results indicate that olfactory cortices are complex: they differ from each other and each is formed from a variable mosaic of neurons. The results suggest that the olfactory cortices are not merely a remnant architype of the primordial forebrain but varied and independent regions.
Topics: Animals; Biomarkers; Brain Mapping; DNA-Binding Proteins; Embryo, Mammalian; Female; Gene Expression Regulation, Developmental; Mice; Mice, Inbred C57BL; Neocortex; Nerve Tissue Proteins; Neurons; Olfactory Bulb; Olfactory Cortex; Olfactory Pathways; Pregnancy; Receptors, Steroid; Receptors, Thyroid Hormone; Repressor Proteins; Tissue Distribution; Tumor Suppressor Proteins
PubMed: 26407299
DOI: 10.1371/journal.pone.0138541 -
The Journal of Comparative Neurology Nov 2018This study employed a range of neuroanatomical stains to determine the organization of the main and accessory olfactory systems within the brain of the tree pangolin....
This study employed a range of neuroanatomical stains to determine the organization of the main and accessory olfactory systems within the brain of the tree pangolin. The tree pangolin has a typically mammalian olfactory system, but minor variations were observed. The main olfactory system is comprised of the layered main olfactory bulb (MOB), the anterior olfactory nucleus (AON), the rostral olfactory cortex (including the taenia tecta, anterior hippocampal continuation and induseum griseum), the olfactory tubercle (Tu), the lateral olfactory tract (lot) and the olfactory limb of the anterior commissure, the nucleus of the lateral olfactory tract (NLOT), the piriform cortex (PIR) and a typically mammalian rostral migratory stream (RMS). The accessory olfactory system included the layered accessory olfactory bulb (AOB) and the nucleus of the accessory olfactory tract (NAOT). Volumetric analysis of the relative size of the MOB and PIR indicate that the tree pangolin has an olfactory system that occupies a proportion of the brain typical for the majority of mammals. Within the MOB, the glomeruli of the tree pangolin, at 200 μm diameter, are larger than observed in most other mammalian species, and the MOB lacks a distinct internal plexiform layer. In addition, the laminate appearance of the NLOT was not observed in the tree pangolin. The accessory olfactory system appears to lack the posterior compartment of the accessory olfactory bulb. These observations are contextualized in relation to olfactory-mediated behaviors in pangolins.
Topics: Animals; Brain; Eutheria; Olfactory Pathways
PubMed: 30078195
DOI: 10.1002/cne.24510 -
Neuroreport Aug 2014Parkinson's disease is a neurodegenerative disease which often presents hyposmia (80-90% of the cases). We characterized the olfactory behavior in the model of...
Parkinson's disease is a neurodegenerative disease which often presents hyposmia (80-90% of the cases). We characterized the olfactory behavior in the model of 6-hydroxydopamine of Parkinson's disease. Mice were trained to discriminate between two odorants in a radial maze. One of the odorants was associated with water as a reward. 6-hydroxydopamine was injected directly into the dorsal striatum; after complete striatal denervation, olfactory performance was evaluated in a radial maze. In the first evaluation, experimental mice performed as control mice. After the first evaluation, the narine of the contralateral side to the striatal injection was closed and mice were evaluated again. The experimental group completely lost the capacity to discriminate between the odorant associated with the reward (heptaldehyde) and the unconditioned odorant (2-heptanone). We propose that the olfactory deficit was caused by dopaminergic denervation to the olfactory tubercle and nucleus accumbens.
Topics: Amphetamine; Animals; Central Nervous System Stimulants; Corpus Striatum; Discrimination, Psychological; Disease Models, Animal; Functional Laterality; Immunohistochemistry; Male; Maze Learning; Mice, Inbred BALB C; Mice, Inbred C57BL; Motor Activity; Neuropsychological Tests; Olfactory Perception; Oxidopamine; Parkinsonian Disorders; Reward
PubMed: 25006848
DOI: 10.1097/WNR.0000000000000218 -
Frontiers in Neurology 2020Autoimmune encephalitic syndromes include mutism, somnolence, movement disorder, and behavioral, or psychiatric symptoms. When paired with bilateral basal ganglia...
Autoimmune encephalitic syndromes include mutism, somnolence, movement disorder, and behavioral, or psychiatric symptoms. When paired with bilateral basal ganglia lesions on magnetic resonance imaging, these support the diagnosis of basal ganglia encephalitis (BGE). BGE is a rare but distinct entity of putative autoimmune etiology, with specific basal ganglia inflammation and acute movement disorders. A previous study identified dopamine-2 receptors (D2R) antibody to be positive in most BGE children, indicating that the D2R antibody may trigger the downstream pathological process in BGE patients. The highest levels of D2R are found in the striatum, the nucleus accumbens, and the olfactory tubercle. D2R antibody-positive BGE is widely reported in children. Here we present a 17-year-old girl with a typical clinical feature of basal ganglia encephalitis, who benefited from immune therapy.
PubMed: 32612568
DOI: 10.3389/fneur.2020.00471 -
Neuroscience Feb 2015The islands of Calleja (IC) are dense clusters of cells localized within the ventral striatum. The IC have been described as variable in both number and localization...
The islands of Calleja (IC) are dense clusters of cells localized within the ventral striatum. The IC have been described as variable in both number and localization from animal-to-animal, however, a quantitative investigation of this variability is unavailable. Further, it is presently unknown whether the IC occupy select areas of the olfactory tubercle (OT), the ventral striatum structure which possesses the IC in mice. To address these questions, we examined the IC of adult C57bl/6 mice. As previously noted, we found substantial inter-hemispheric and inter-mouse variations in the total number of IC. While the IC were observed in all three cell layers of the OT, the bulk of IC occupied layer iii. The span of the IC along the anterior-posterior and medial-lateral axes of the OT was variant. Further, localizations of the IC within the OT also differed across animals. Notably, the probability of observing an IC in the medial OT was greater than that of observing one in the lateral. These data provide a fundamental characterization of both differences and similarities regarding the IC in mice and will be informative for future in vivo studies seeking to perturb and possibly record from the IC. Further, we predict that inter-animal diversity in the IC may be a mechanism for inter-animal differences in behavior, especially reward-related and motivational behaviors.
Topics: Animals; Cell Count; Islands of Calleja; Male; Mice; Mice, Inbred C57BL; Neurons
PubMed: 25536047
DOI: 10.1016/j.neuroscience.2014.12.019 -
Frontiers in Behavioral Neuroscience 2016Ethanol and caffeine are frequently consumed in combination and have opposite effects on the adenosine system: ethanol metabolism leads to an increase in adenosine...
Ethanol and caffeine are frequently consumed in combination and have opposite effects on the adenosine system: ethanol metabolism leads to an increase in adenosine levels, while caffeine is a non-selective adenosine A/A receptor antagonist. These receptors are highly expressed in striatum and olfactory tubercle, brain areas involved in exploration and social interaction in rodents. Ethanol modulates social interaction processes, but the role of adenosine in social behavior is still poorly understood. The present work was undertaken to study the impact of ethanol, caffeine and their combination on social behavior, and to explore the involvement of A and A receptors on those actions. Male CD1 mice were evaluated in a social interaction three-chamber paradigm, for preference of conspecific vs. object, and also for long-term recognition memory of familiar vs. novel conspecific. Ethanol showed a biphasic effect, with low doses (0.25 g/kg) increasing social contact and higher doses (1.0-1.5 g/kg) reducing social interaction. However, no dose changed social preference; mice always spent more time sniffing the conspecific than the object, independently of the ethanol dose. Ethanol, even at doses that did not change social exploration, produced amnestic effects on social recognition the following day. Caffeine reduced social contact (15.0-60.0 mg/kg), and even blocked social preference at higher doses (30.0-60.0 mg/kg). The A antagonist Cyclopentyltheophylline (CPT; 3-9 mg/kg) did not modify social contact or preference on its own, and the A antagonist MSX-3 (1.5-6 mg/kg) increased social interaction at all doses. Ethanol at intermediate doses (0.5-1.0 g/kg) was able to reverse the reduction in social exploration induced by caffeine (15.0-30.0 mg/kg). Although there was no interaction between ethanol and CPT or MSX-3 on social exploration in the first day, MSX-3 blocked the amnestic effects of ethanol observed on the following day. Thus, ethanol impairs the formation of social memories, and A adenosine antagonists can prevent the amnestic effects of ethanol, so that animals can recognize familiar conspecifics. On the other hand, ethanol can counteract the social withdrawal induced by caffeine, a non-selective adenosine A/A receptor antagonist. These results show the complex set of interactions between ethanol and caffeine, some of which could be the result of the opposing effects they have in modulating the adenosine system.
PubMed: 27853423
DOI: 10.3389/fnbeh.2016.00206