entorhinal cortex
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Footshock is frequently used as an unconditioned stimulus in fear conditioning behavior studies. The medial entorhinal cortex (MEC) contributes to fear learning and receives neuronal inputs from the claustrum. However, whether footshocks can induce a neuronal response in claustrum-MEC (CLA-MEC) projection remains unknown. Here, we combined fiber-based Ca2+ recordings with a retrograde AAV labeling method to investigate neuronal responses of MEC-projecting claustral neurons to footshock stimulation in freely moving mice. We achieved successful Ca2+ recordings in both anesthetized and freely exploring mice. We found that footshock stimulation reliably induced neuronal responses to MEC-projecting claustral neurons. Therefore, the footshock-induced response detected in the CLA-MEC projection suggests its potential role in fear processin.
- MeSH
- cortex entorhinalis * fyziologie MeSH
- klaustrum * MeSH
- myši MeSH
- neurony fyziologie MeSH
- strach MeSH
- vápník MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- cortex entorhinalis účinky léků MeSH
- epilepsie etiologie prevence a kontrola MeSH
- inhibitory syntézy nukleových kyselin farmakologie MeSH
- krysa rodu rattus MeSH
- methotrexát farmakologie MeSH
- nedostatek hořčíku patofyziologie MeSH
- počet buněk MeSH
- těhotenství MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- těhotenství MeSH
- zvířata MeSH
The recently introduced orientation selective deep brain stimulation (OS-DBS) technique freely controls the direction of the electric field's spatial gradient by using multiple contacts with independent current sources within a multielectrode array. The goal of OS-DBS is to align the electrical field along the axonal track of interest passing through the stimulation site. Here we utilized OS-DBS with a planar 3-channel electrode for stimulating the rat entorhinal cortex (EC) and medial septal nucleus (MSN), two promising areas for DBS treatment of Alzheimer's disease. The brain responses to OS-DBS were monitored by whole brain functional magnetic resonance imaging (fMRI) at 9.4 T with Multi-Band Sweep Imaging with Fourier Transformation (MB-SWIFT). Varying the in-plane OS-DBS stimulation angle in the EC resulted in activity modulation of multiple downstream brain areas involved in memory and cognition. Contrary to that, no angle dependence of brain activations was observed when stimulating the MSN, consistent with predictions based on the electrode configuration and on the main axonal directions of the targets derived from diffusion MRI tractography and histology. We conclude that tuning the OS-DBS stimulation angle modulates the activation of brain areas relevant to Alzheimer's disease, thus holding great promise in the DBS treatment of the disease.
- MeSH
- Alzheimerova nemoc * diagnostické zobrazování terapie MeSH
- cortex entorhinalis diagnostické zobrazování fyziologie MeSH
- hluboká mozková stimulace * metody MeSH
- kognice MeSH
- krysa rodu rattus MeSH
- magnetická rezonanční tomografie metody MeSH
- mozek MeSH
- septální jádra * MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
PURPOSE: Stereotactic radiofrequency amygdalohippocampectomy (SAHE) has been modified recently in our center for the therapy of mesial temporal epilepsy (MTLE). It has promising clinical results comparable with microsurgical amygdalohippocampectomy despite smaller volume reduction of the hippocampus. We hypothesized that the extent of perirhinal and entorhinal cortex (PRC, EC) reduction could explain the clinical outcome. Therefore, we performed, retrospectively, volumetric analysis of PRC and EC and compared it with the seizure control. METHODS: Twenty-six consecutive patients with MTLE treated by SAHE were included. PRC and EC volumes were measured from magnetic resonance imaging (MRI) records obtained before and 1 year after SAHE. The clinical outcome was assessed each year after SAHE using Engel's classification. KEY FINDINGS: Twenty-six patients were analyzed. The volume of PRC decreased by 46 ± 17% (p < 10(-12) ); EC volume decreased by 56 ± 20% (p < 10(-10) ). Two years after the procedure, 73% of patients were classified as Engel's I, 19% as Engel's II; in 2 (8%) the treatment failed (were reoperated). Eighteen patients finished 3 years follow-up; 72% of them were classified as Engel's I, 17% as Engel's II, and in 2 (11%) above-mentioned patients the treatment failed. Thirteen patients finished 4 years of follow-up, 11 of them as Engel's I. There was no significant correlation of the clinical outcome to PRC and EC volume reductions. SIGNIFICANCE: The clinical effect of SAHE is not clearly explained by the volume reductions of PRC and EC (nor of the hippocampus and the amygdala). It promotes opinion that the extent of resection/destruction is not important for seizure outcomes.
- MeSH
- amygdala patologie chirurgie MeSH
- cortex entorhinalis patologie chirurgie MeSH
- dospělí MeSH
- elektrokoagulace metody MeSH
- epilepsie temporálního laloku patologie chirurgie MeSH
- hipokampus patologie chirurgie MeSH
- lidé středního věku MeSH
- lidé MeSH
- magnetická rezonanční tomografie MeSH
- mapování mozku MeSH
- mladiství MeSH
- radiochirurgie přístrojové vybavení metody MeSH
- výsledek terapie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by the loss of cognitive functions, reflecting pathological damage to the medial prefrontal cortex (mPFC) as well as to the hippocampus and the entorhinal cortex. Astrocytes maintain the internal homeostasis of the CNS and are fundamentally involved in neuropathological processes, including AD. Here, we analysed the astrocytic cytoskeletal changes within the mPFC of a triple transgenic mouse model of AD (3 × Tg-AD) by measuring the surface area and volume of glial fibrillary acidic protein (GFAP)-positive profiles in relation to the build-up and presence of amyloid-β (Aβ), and compared the results with those found in non-transgenic control animals at different ages. 3 × Tg-AD animals showed clear astroglial cytoskeletal atrophy, which appeared at an early age (3 months; 33% and 47% decrease in GFAP-positive surface area and volume, respectively) and remained throughout the disease progression at 9, 12 and 18 months old (29% and 36%; 37% and 35%; 43% and 37%, respectively). This atrophy was independent of Aβ accumulation, as only a few GFAP-positive cells were localized around Aβ aggregates, which suggests no direct relationship with Aβ toxicity. Thus, our results indicate that the progressive reduction in astrocytic branching and domain in the mPFC can account for the integrative dysfunction leading to the cognitive deficits and memory disturbances observed in AD.
- MeSH
- Alzheimerova nemoc patologie MeSH
- amyloidní beta-protein metabolismus MeSH
- astrocyty cytologie metabolismus patologie MeSH
- atrofie patologie MeSH
- cytoskelet patologie MeSH
- imunohistochemie MeSH
- modely nemocí na zvířatech MeSH
- myši transgenní MeSH
- myši MeSH
- prefrontální mozková kůra cytologie metabolismus patologie MeSH
- progrese nemoci MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Neuronální úbytek jako charakteristický rys Alzheimerovy nemoci (AN) se může nepřímo posuzovat na magnetické rezonanci (MR) podle celkové nebo regionální atrofie mozku. Mediotemporální atrofie je pro AN typická, leč nespecifická. Ke zvýšení diagnostické vý¬ těžnosti z jednorázového MR vyšetření jsme se zaměřiU na vybrané oblasti mozkové kůry a bílé hmoty. U 20 pacientů s pravděpodobnou AN a 20 kontrolních seniorů jsme změřili tloušťku, šířku či výšku následujících oblastí v obou hemisférach: a) šedá hmota mozková - entorinální kůra (EC), dvě oblasti frontální kůry (dorsálně Fl, ventrálně F2), temporální (T) kůra a okcipitální kůra, b) bílá hmota mozková - capsula interna (CI), corpus callosum. Oproti kontrolním seniorům měli pacienti s AN významně atrofovány tyto oblasti: pravá a levá EC, levá F2 kůra, pravá T kůra a všechny oblasti měřené bílé hmoty, nejvíce levá capsula interna. Významná asymetrie u AN byla prokázána pro EC a F2 kůru. AN vede k difúzni atrofii mozku, z níž největší úbytek mozkové tkáně nastává v oblasti EC oboustranně a v levé CI. Degenerativní proces postihuje nerovnoměrně pravou a levou hemisféru, především v kůře EC a F2.
Neuronal loss as a feature of Alzheimer's disease (AD) may be indirectly assessed on magnetic resonance (MR) according to the total or regional brain atrophy. Mediotemporal atrophy is typical for AD, but not specific. To increase the diagnostic yield from a single MR examination, we focused on selected areas of the cortex and the white matter. We measured the thickness, the width or the height of the following areas in both hemispheres in 20 patients with probable AD and 20 control elderly people: a) the grey matter – entorhinal cortex (EC), two frontal cortical areas (dorsal F1, ventral F2), temporal (T) cortex and occipital cortex, b) the white matter – internal capsule (CI), corpus callosum. Compared to control elderly patients, AD patients had significantly atrophied following areas: right and left EC, left F2 cortex, right T cortex, and all parts measured in the white matter, the most pronounced change being in the left internal capsule. A significant asymmetry in AD was observed for the EC and F2 cortices. AD results in a diffuse brain atrophy, from which the greatest loss of brain tissue occurs in the EC bilaterally and the left CI. A degenerative process disproportionately affects the right and left hemisphere, especially in the EC and F2 cortices.
Objectives: Mild behavioral impairment (MBI) is a syndrome describing late-onset persistent neuropsychiatric symptoms (NPS) in non-demented older adults. Few studies to date have investigated the associations of MBI with structural brain changes. Our aim was to explore structural correlates of NPS in a non-demented memory clinic sample using the Mild Behavioral Impairment Checklist (MBI-C) that has been developed to measure MBI. Methods: One hundred sixteen non-demented older adults from the Czech Brain Aging Study with subjective cognitive concerns were classified as subjective cognitive decline (n = 37) or mild cognitive impairment (n = 79). Participants underwent neurological and neuropsychological examinations and brain magnetic resonance imaging (MRI) (1.5 T). The Czech version of the MBI-C was administered to participants' informants. Five a priori selected brain regions were measured, namely, thicknesses of the orbitofrontal cortex (OFC), anterior cingulate cortex (ACC), posterior cingulate cortex (PCC), and entorhinal cortex (ERC) and volume of the hippocampus (HV), and correlated with MBI-C total and domain scores. Results: Entorhinal cortex was associated with MBI-C total score (rS = -0.368, p < 0.001) and with impulse dyscontrol score (rS = -0.284, p = 0.002). HV was associated with decreased motivation (rS = -0.248, p = 0.008) and impulse dyscontrol score (rS = -0.240, p = 0.011). Conclusion: Neuropsychiatric symptoms, particularly in the MBI impulse dyscontrol and motivation domains, are associated with medial temporal lobe atrophy in a clinical cohort of non-demented older adults. This study supports earlier involvement of temporal rather than frontal regions in NPS manifestation. Since these regions are typically affected early in the course of Alzheimer's disease (AD), the MBI-C may potentially help further identify individuals at-risk of developing AD dementia.
- Publikační typ
- časopisecké články MeSH
The perirhinal cortex (PRC) composed of areas 35 and 36 forms an important route for activity transfer between the hippocampus-entorhinal cortex and neocortex. Its function in memory formation and consolidation as well as in the initiation and spreading of epileptic activity was already partially elucidated. We studied the general pattern of calretinin (CR), parvalbumin (PV) and calbindin (CB) immunoreactivity and its corrected relative optical density (cROD) as well as morphological features and density of CR and PV immunoreactive (CR+, PV+) interneurons in the rat PRC. Neighboring neocortical association area Te3V was analyzed as well. The PRC differed from the Te3V in higher CR and lower PV overall immunoreactivity level. On CR immunostained sections, the difference between high cROD value in area 35 and low cROD value in area Te3V reached statistical significance (p<0.05). The pattern of CB immunoreactivity was similar to that of the neocortex. Vertically oriented bipolar neurons were the most common morphological type of CR+ neurons, multipolar neuronal morphology was typical among PV+ neurons and vertically oriented bipolar neurons and multipolar neurons were approximately equally frequent among CB+ neurons. The density of CR+ and PV+ neurons was stereologically measured. While the density of PV+ neurons was not significantly different in PRC when compared to Te3V, density of CR+ neurons in area 35 was significantly higher by comparison with Te3V (p<0.05). Further, the overall neuronal density was measured on Nissl stained sections and the proportion of CR+ and PV+ interneurons was expressed as a percentage of the total neurons counts. The percentage of CR+ interneurons was higher in area 35 by comparison with area Te3 (p<0.05), while the percentage of PV+ interneurons did not significantly differ among the examined areas. In conclusion, the PRC possesses specific interneuronal equipment with unusually high proportion of CR+ interneurons, what might be of importance for the presumed gating function of PRC in normal and diseased states.
- MeSH
- interneurony chemie metabolismus MeSH
- krysa rodu rattus MeSH
- mozková kůra chemie metabolismus MeSH
- neurony chemie metabolismus MeSH
- parvalbuminy analýza metabolismus MeSH
- S100 kalcium vázající protein G analýza metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
