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Neurobiology of Disease Apr 2022Acute injuries or insults to the cortex, such as trauma, subarachnoid hemorrhage, lobar hemorrhage, can cause seizures or status epilepticus(SE). Neocortical SE is...
OBJECTIVES
Acute injuries or insults to the cortex, such as trauma, subarachnoid hemorrhage, lobar hemorrhage, can cause seizures or status epilepticus(SE). Neocortical SE is associated with coma, worse prognosis, delayed recovery, and the development of epilepsy. The anatomical structures progressively recruited during neocortical-onset status epilepticus (SE) is unknown. Therefore, we constructed large-scale maps of brain regions active during neocortical SE.
METHODS
We used a neocortical injury-induced SE mouse model. We implanted cobalt (Co) in the right supplementary motor cortex (M2). We 16 h later administered a homocysteine injection (845 mg/kg, intraperitoneal) to C57Bl/6 J mice to induce SE and monitored it by video and EEG. We harvested animals for 1 h (early-stage) and 2 h (late-stage) following homocysteine injections. To construct activation maps, we immunolabeled whole-brain sections for cFos and NeuN, imaged them using a confocal microscope and quantified cFos immunoreactivity (IR).
RESULTS
SE in the early phase consisted of discrete, focal intermittent seizures, which became continuous and bilateral in the late stage. In this early stage, cFos IR was primarily observed in the right hemisphere, ipsilateral to the Co lesion, specifically in the motor cortex, retrosplenial cortex, somatosensory cortex, anterior cingulate cortex, lateral and medial septal nuclei, and amygdala. We observed bilateral cFos IR in brain regions during the late stage, indicating the bilateral spread of focal seizures. We found increased cFOS IR in the bilateral somatosensory cortex and the motor cortex and subcortical regions, including the amygdala, thalamus, and hypothalamus. There was noticeably different, intense cFos IR in the bilateral hippocampus compared to the early stage. In addition, there was higher activity in the cortex ipsilateral to the seizure focus during the late stage compared with the early one.
CONCLUSION
We present a large-scale, high-resolution map of seizure spread during neocortical injury-induced SE. Cortico-cortical and cortico subcortical re-entrant circuits sustain neocortical SE. Neuronal loss following neocortical SE, distant from the neocortical focus, may result from seizures.
Topics: Animals; Hippocampus; Mice; Neocortex; Neurons; Seizures; Status Epilepticus
PubMed: 35065250
DOI: 10.1016/j.nbd.2022.105633 -
Annals of Clinical and Translational... Dec 2023Further understanding of the function and regulatory mechanism of cholinergic neural circuits and related neurodegenerative diseases. (Review)
Review
OBJECTIVE
Further understanding of the function and regulatory mechanism of cholinergic neural circuits and related neurodegenerative diseases.
METHODS
This review summarized the research progress of the central cholinergic nervous system, especially for the cholinergic circuit of the medial septal nucleus-hippocampus, vertical branch of diagonal band-hippocampus, basal nucleus of Meynert-cerebral cortex cholinergic loop, amygdala, pedunculopontine nucleus, and striatum-related cholinergic loops.
RESULTS
The extensive and complex fiber projection of cholinergic neurons form the cholinergic neural circuits, which regulate several nuclei in the brain through neurotransmission and participate in learning and memory, attention, emotion, movement, etc. The loss of cholinergic neurotransmitters, the reduction, loss, and degeneration of cholinergic neurons or abnormal theta oscillations and cholinergic neural circuits can induce cognitive disorders such as AD, PD, PDD, and DLB.
INTERPRETATION
The projection and function of cholinergic fibers in some nuclei and the precise regulatory mechanisms of cholinergic neural circuits in the brain remain unclear. Further investigation of cholinergic fiber projections in various brain regions and the underlying mechanisms of the neural circuits are expected to open up new avenues for the prevention and treatment of senile neurodegenerative diseases.
Topics: Humans; Central Nervous System; Hippocampus; Cerebral Cortex; Neurodegenerative Diseases; Cholinergic Agents
PubMed: 37846148
DOI: 10.1002/acn3.51920 -
Clinical Parkinsonism & Related... 2022Parkinson's disease (PD) mainly affects basal ganglia including septal nuclei. Septal nuclei have extensive cholinergic connections with thalamus and brain stem nuclei....
OBJECTIVE
Parkinson's disease (PD) mainly affects basal ganglia including septal nuclei. Septal nuclei have extensive cholinergic connections with thalamus and brain stem nuclei. We hypothesized that the degeneration of septal nuclei has an impact on dopaminergic (motor) and non-dopaminergic (cognitive) symptoms in PD.
METHOD
Clinical and MRI data of 80 patients with Parkinson's disease and 20 healthy controls (HC) with a structural magnetic resonance imaging (MRI) were selected from their first visit from PPMI database. Septal nuclei were manually segmented from T1W images according to previously established anatomical criteria. In addition, subcortical structures such as thalamus, amygdala, hippocampus, caudate, putamen, pallidum and accumbens were automatically segmented.
RESULTS
Volume of septal nuclei in the patients with PD was decreased in comparison with controls. These changes were independent of volume changes in other subcortical grey structure in PD. In addition, we found a correlation between motor components of unified Parkinson's disease rating scale (UPDRS) and volume of septal nuclei in PD. Other clinical measures such as olfactory test, upper extremity function (mobility) performance, total UPDRS, lower extremity function (mobility) performance, and cognitive function were significantly more in PD group than in control. No correction was found between cognitive function and volume of septal nuclei.
CONCLUSION
We concluded that septal nuclei is distinctly affected in PD and is strongly associated with motor impairment. This may be a modulatory effect of cholinergic system on dopaminergic and glutamergic system. It is suggested that volume of septal nuclei may be a useful biomarker in PD diagnosis and monitoring.
PubMed: 36338824
DOI: 10.1016/j.prdoa.2022.100171 -
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 -
Biological Psychiatry May 2024Social memory, the ability to recognize and remember individuals within a social group, is crucial for social interactions and relationships. Deficits in social memory... (Review)
Review
Social memory, the ability to recognize and remember individuals within a social group, is crucial for social interactions and relationships. Deficits in social memory have been linked to several neuropsychiatric and neurodegenerative disorders. The hippocampus, especially the circuit that links dorsal CA2 and ventral CA1 neurons, is considered a neural substrate for social memory formation. Recent studies have provided compelling evidence of extrahippocampal contributions to social memory. The septal nuclei, including the medial and lateral septum, make up a basal forebrain region that shares bidirectional neuronal connections with the hippocampus and has recently been identified as critical for social memory. The focus of our review is the neural circuit mechanisms that underlie social memory, with a special emphasis on the septum. We also discuss the social memory dysfunction associated with neuropsychiatric and neurodegenerative disorders.
PubMed: 38718881
DOI: 10.1016/j.biopsych.2024.04.018 -
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 -
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 -
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