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The Journal of Comparative Neurology Oct 2022The current study provides a detailed architectural analysis of the subpallial telencephalon of the tree pangolin. In the tree pangolin, the subpallial telencephalon was...
The current study provides a detailed architectural analysis of the subpallial telencephalon of the tree pangolin. In the tree pangolin, the subpallial telencephalon was divided into septal and striatopallidal regions. The septal region contained the septal nuclear complex, diagonal band of Broca, and the bed nuclei of the stria terminalis. The striatopallidal region comprised of the dorsal (caudate, putamen, internal and external globus pallidus) and ventral (nucleus accumbens, olfactory tubercle, ventral pallidum, nucleus basalis, basal part of the substantia innominata, lateral stripe of the striatum, navicular nucleus, and the major island of Calleja) striatopallidal complexes. In the tree pangolin, the organization and numbers of nuclei forming these regions and complexes, their topographical relationships to each other, and the cyto-, myelo-, and chemoarchitecture, were found to be very similar to that observed in commonly studied mammals. Minor variations, such as less nuclear parcellation in the bed nuclei of the stria terminalis, may represent species-specific variations, or may be the result of the limited range of stains used. Given the overall similarity across mammalian species, it appears that the subpallial telencephalon of the mammalian brain is highly conserved in terms of evolutionary changes detectable with the methods used. It is also likely that the functions associated with these nuclei in other mammals can be translated directly to the tree pangolin, albeit with the understanding that the stimuli that produce activity within these regions may be specific to the life history requirements of the tree pangolin.
Topics: Animals; Brain; Pangolins; Septum of Brain; Telencephalon
PubMed: 35708120
DOI: 10.1002/cne.25353 -
Behavioural Brain Research Jan 2021Accurate discrimination between safe and dangerous stimuli is essential for survival. Prior research has begun to uncover the neural structures that are necessary for...
Accurate discrimination between safe and dangerous stimuli is essential for survival. Prior research has begun to uncover the neural structures that are necessary for learning this discrimination, but exploration of brain regions involved in this learning process has been mostly limited to males. Recent findings show sex differences in discrimination learning, with reduced fear expression to safe cues in females compared to males. Here, we used male and female Sprague Dawley rats to explore neural activation, as measured by Fos expression, in fear and safety learning related brain regions. Neural activation after fear discrimination (Discrimination) was compared between males and females, as well as with fear conditioned (Fear Only) and stimulus presented (Control) conditions. Correlations of discrimination ability and neural activation were also calculated. We uncovered a correlation between central amygdala (CeA) activation and discrimination abilities in males and females. Anterior medial bed nucleus of the stria terminalis (BNST) was the only region where sex differences in Fos counts were observed in the Discrimination condition, and the only region where neural activation significantly differed between Fear Only and Discrimination conditions. Together, these findings indicate the importance of fear expression circuitry in mediating discrimination responses and generate important questions for future investigation.
Topics: Animals; Behavior, Animal; Central Amygdaloid Nucleus; Conditioning, Classical; Discrimination Learning; Fear; Male; Proto-Oncogene Proteins c-fos; Rats; Rats, Sprague-Dawley; Septal Nuclei; Sex Characteristics
PubMed: 32871228
DOI: 10.1016/j.bbr.2020.112884 -
Journal of Alzheimer's Disease : JAD 2020The hippocampus, entorhinal cortex, and basal forebrain are among the first brain structures affected by Alzheimer's disease (AD). They play an essential role in spatial...
BACKGROUND
The hippocampus, entorhinal cortex, and basal forebrain are among the first brain structures affected by Alzheimer's disease (AD). They play an essential role in spatial pattern separation, a process critical for accurate encoding of similar spatial information.
OBJECTIVE
Our aim was to examine spatial pattern separation and its association with volumetric changes of the hippocampus, entorhinal cortex, and basal forebrain nuclei projecting to the hippocampus (the medial septal nuclei and vertical limb of the diagonal band of Broca - Ch1-2 nuclei) in the biomarker-defined early clinical stages of AD.
METHODS
A total of 98 older adults were recruited from the Czech Brain Aging Study cohort. The participants with amnestic mild cognitive impairment (aMCI) due to AD (n = 44), mild AD dementia (n = 31), and cognitively normal older adults (CN; n = 23) underwent spatial pattern separation testing, comprehensive cognitive assessment, and MRI brain volumetry.
RESULTS
Spatial pattern separation accuracy was lower in the early clinical stages of AD compared to the CN group (p < 0.001) and decreased with disease severity (CN > aMCI due to AD > AD dementia). Controlling for general memory and cognitive performance, demographic characteristics and psychological factors did not change the results. Hippocampal and Ch1-2 volumes were directly associated with spatial pattern separation performance while the entorhinal cortex operated on pattern separation indirectly through the hippocampus.
CONCLUSION
Smaller volumes of the hippocampus, entorhinal cortex, and basal forebrain Ch1-2 nuclei are linked to spatial pattern separation impairment in biomarker-defined early clinical AD and may contribute to AD-related spatial memory deficits.
Topics: Aged; Aged, 80 and over; Aging; Alzheimer Disease; Brain; Cognitive Dysfunction; Cohort Studies; Cross-Sectional Studies; Czech Republic; Female; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Photic Stimulation; Space Perception
PubMed: 32444544
DOI: 10.3233/JAD-200093 -
Current Medical Mycology 2020is a widely distributed anthropophilic dermatophyte causing different diseases of skin. In the literature limited data are available about the morphogenesis of...
BACKGROUND AND PURPOSE
is a widely distributed anthropophilic dermatophyte causing different diseases of skin. In the literature limited data are available about the morphogenesis of vegetative mycelium of and related anthropophilic dermatophytes. The aim of present study was to describe ultrastructural patterns of development, cellular organellography and septal pore apparatus structure of growing vegetative mycelium of .
MATERIALS AND METHODS
strain RCPFF 214/898 was grown on solid Czapek's Agar (CzA) at 28ºС. For investigation of colonies morphology we used methods of light-, scanning and transmission electron microscopy (SEM and TEM).
RESULTS
Differences in morphogenesis of aerial and substrate hyphae were revealed. Mitochondrial reticulum and fibrosinous bodies were shown in for the first time. The septal pore apparatus in hyphal cells of was comprised Woronin bodies and septal pore plugs. Woronin bodies (0.18 µm), located with 1‒4 near the pore, were spherical, membrane-bound, and had a homogeneous, electron-dense content. The cells of aerial and submerged hyphal cells of contain two nuclei.
CONCLUSION
Mature cells of substrate hyphae appeared more active than comparable cells in the aerial mycelium. During the maturation process, the differences in number and morphology of mitochondria, number of vacuoles, and in the synthesis of different types of storage substances were revealed. Presence of "mitochondrial reticulum" and variable types of storage substances in submerged hyphal cells suggested higher levels of metabolic activity compared to aerial mycelium.
PubMed: 32420507
DOI: 10.18502/cmm.6.1.2508 -
CNS Spectrums Feb 2022In this review, we describe proposed circuits mediating the mechanism of action of pherines, a new class of synthetic neuroactive steroids with demonstrated antianxiety... (Review)
Review
In this review, we describe proposed circuits mediating the mechanism of action of pherines, a new class of synthetic neuroactive steroids with demonstrated antianxiety and antidepressant properties, that engage nasal chemosensory receptors. We hypothesize that afferent signals triggered by activation of these peripheral receptors could reach subgroups of olfactory bulb neurons broadcasting information to gamma-aminobutyric acid (GABAergic) and corticotropin-releasing hormone (CRH) neurons in the limbic amygdala. We propose that chemosensory inputs triggered by pherines project to centrolateral (CeL) and centromedial (CeM) amygdala neurons, with downstream effects mediating behavioral actions. Anxiolytic pherines could activate the forward inhibitory GABAergic neurons that facilitate the release of neuropeptide S (NPS) in the locus coeruleus (LC) and GABA in the bed nucleus of the stria terminalis (BNST) and inhibit catecholamine release in the LC and ventral tegmental area (VTA) leading to rapid anxiolytic effect. Alternatively, antidepressant pherines could facilitate the CRH and GABAergic neurons that inhibit the release of NPS from the LC, increase glutamate release from the BNST, and increase norepinephrine (NE), dopamine (DA), and serotonin release from the LC, VTA, and raphe nucleus, respectively. Activation of these neural circuits leads to rapid antidepressant effect. The information provided is consistent with this model, but it should be noted that some steps on these pathways have not been demonstrated conclusively in the human brain.
Topics: Anti-Anxiety Agents; Antidepressive Agents; Corticotropin-Releasing Hormone; Humans; Septal Nuclei; Ventral Tegmental Area
PubMed: 33092667
DOI: 10.1017/S109285292000190X -
Cell Reports Nov 2022Stress is a risk factor for emotion and energy metabolism disorders. However, the neurocircuitry mechanisms for emotion initiation and glucose mobilization underlying...
Stress is a risk factor for emotion and energy metabolism disorders. However, the neurocircuitry mechanisms for emotion initiation and glucose mobilization underlying stress responses are unclear. Here we demonstrate that photoactivation of Gad2+ projection from the anterior bed nucleus of the stria terminalis (aBNST) to the arcuate nucleus (ARC) induces anxiety-like behavior as well as acute hyperglycemia. Photoinhibition of the circuit is anxiolytic and blocks hyperglycemia induced by restraint stress. Pharmacogenetic inhibition of the ARC→raphe obscurus nucleus (ROb) and photoactivation of the aBNST→ARC circuits simultaneously leads to significant hypoglycemia and anxiety-like behavior. Pharmacogenetic inhibition of the ARC→nucleus of the solitary tract (NTS) whilst photoactivation of the aBNST→ARC circuit only induces hyperglycemia. Our results reveal that the aBNST→ARC→ROb circuit is recruited for the stress response of rapid glucose mobilization and the aBNST→ARC→NTS circuit for behavioral symptoms of stress response. This study identifies a possible general strategy for neurocircuitry structural organization dealing with multiple organs involved in responses, with potential therapeutic targets for emotion and energy metabolism disorders underlying psychiatric disorders.
Topics: Humans; Glucose; Septal Nuclei; Anxiety; Arcuate Nucleus of Hypothalamus; Hyperglycemia
PubMed: 36351404
DOI: 10.1016/j.celrep.2022.111586 -
NeuroImage Apr 2020The bed nucleus of the stria terminalis (BNST) is emerging as a critical region in multiple psychiatric disorders including anxiety, PTSD, and alcohol and substance use...
The bed nucleus of the stria terminalis (BNST) is emerging as a critical region in multiple psychiatric disorders including anxiety, PTSD, and alcohol and substance use disorders. In conjunction with growing knowledge of the BNST, an increasing number of studies examine connections of the BNST and how those connections impact BNST function. The importance of this BNST network is highlighted by rodent studies demonstrating that projections from other brain regions regulate BNST activity and influence BNST-related behavior. While many animal and human studies replicate the components of the BNST network, to date, structural connections between the BNST and insula have only been described in rodents and have yet to be shown in humans. In this study, we used probabilistic tractography to examine BNST-insula structural connectivity in humans. We used two methods of dividing the insula: 1) anterior and posterior insula, to be consistent with much of the existing insula literature; and 2) eight subregions that represent informative cytoarchitectural divisions. We found evidence of a BNST-insula structural connection in humans, with the strongest BNST connectivity localized to the anteroventral insula, a region of agranular cortex. BNST-insula connectivity differed by hemisphere and was moderated by sex. These results translate rodent findings to humans and lay an important foundation for future studies examining the role of BNST-insula pathways in psychiatric disorders.
Topics: Adolescent; Adult; Cerebral Cortex; Diffusion Tensor Imaging; Echo-Planar Imaging; Female; Humans; Male; Middle Aged; Nerve Net; Septal Nuclei; Sex Characteristics; Sex Factors; Young Adult
PubMed: 31954845
DOI: 10.1016/j.neuroimage.2020.116555 -
Brain Research Oct 2023The hypothalamus plays essential roles in the human brain by regulating feeding, fear, aggression, reproductive behaviors, and autonomic activities. The septal nuclei...
The hypothalamus plays essential roles in the human brain by regulating feeding, fear, aggression, reproductive behaviors, and autonomic activities. The septal nuclei and the bed nucleus of stria terminalis (BNST) are also known to be involved in control of autonomic, motivational, learning, emotional and associative processes in the human brain. Multiple animal dissection studies have revealed direct connectivity between central limbic gray matter nuclei and occipital cortex, particularly from the hypothalamic, septal and BNST nuclei. However, the detailed anatomy of this connectivity in the human brain has yet to be determined. The primary objective of this study was to explore the utility of high spatial and high angular resolution diffusion weighted tractography techniques for mapping the connectivity pathways between the occipital cortex and central limbic gray matter nuclei in the human brain. We studied 30 healthy adult human brains, delineated, and reconstructed the trajectory of the occipito-hypothalamic/septal/BNST for the first time in the human brain.
Topics: Adult; Animals; Humans; Septal Nuclei; Brain; Diffusion Tensor Imaging; Hypothalamus; Occipital Lobe
PubMed: 37488033
DOI: 10.1016/j.brainres.2023.148510 -
ELife Dec 2021The septum is a ventral forebrain structure known to regulate innate behaviors. During embryonic development, septal neurons are produced in multiple proliferative areas...
The septum is a ventral forebrain structure known to regulate innate behaviors. During embryonic development, septal neurons are produced in multiple proliferative areas from neural progenitors following transcriptional programs that are still largely unknown. Here, we use a combination of single-cell RNA sequencing, histology, and genetic models to address how septal neuron diversity is established during neurogenesis. We find that the transcriptional profiles of septal progenitors change along neurogenesis, coinciding with the generation of distinct neuron types. We characterize the septal eminence, an anatomically distinct and transient proliferative zone composed of progenitors with distinctive molecular profiles, proliferative capacity, and fate potential compared to the rostral septal progenitor zone. We show that -expressing septal eminence progenitors give rise to neurons belonging to at least three morphological classes, born in temporal cohorts that are distributed across different septal nuclei in a sequential fountain-like pattern. Our study provides insight into the molecular programs that control the sequential production of different neuronal types in the septum, a structure with important roles in regulating mood and motivation.
Topics: Animals; Female; Gene Expression Profiling; Male; Mice; Neurogenesis; Neurons; Septum of Brain; Thyroid Nuclear Factor 1; Transcription, Genetic
PubMed: 34851821
DOI: 10.7554/eLife.71545 -
Current Opinion in Pharmacology Jun 2021Oxytocin regulates a variety of centrally-mediated functions, ranging from socio-sexual behavior, maternal care, and affiliation to fear, stress, anxiety. In the past... (Review)
Review
Oxytocin regulates a variety of centrally-mediated functions, ranging from socio-sexual behavior, maternal care, and affiliation to fear, stress, anxiety. In the past years, both clinical and preclinical studies characterized oxytocin for its modulatory role on reward-related neural substrates mainly involving the interplay with the mesolimbic and mesocortical dopaminergic pathways. This suggests a role of this nonapeptide on the neurobiology of addiction raising the possibility of its therapeutic use. Although far from a precise knowledge of the underlying mechanisms, the putative role of the bed nucleus of the stria terminalis as a key structure where oxytocin may rebalance altered neurochemical processes and neuroplasticity involved in dependence and relapse has been highlighted. This view opens new opportunities to address the health problems related to drug misuse.
Topics: Anxiety; Humans; Neuronal Plasticity; Oxytocin; Septal Nuclei
PubMed: 33845377
DOI: 10.1016/j.coph.2021.03.002