Stratum Lucidum

2020 ◽  
Author(s):  
Keyword(s):  
Stratum Lucidum

scholarly journals A novel approach for locating mice brain regions of Cryptococcus neoformans CNS invasion

2016 ◽  
Vol 11 ◽  
pp. S136-S143
Author(s):  
Chunting He ◽  
Qingfen Chen ◽  
Longkun Zhu
Keyword(s):  
Motor Cortex ◽  
Cryptococcus Neoformans ◽  
Primary Motor Cortex ◽  
Thalamic Nucleus ◽  
Molecular Layer ◽  
Brain Regions ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Novel Approach ◽  
Stratum Lucidum ◽  
Lateral Posterior

Aim of this study was to locate the brain regions where Cryptococcus interact with brain cells and invade into brain. After 7 days of intratracheal inocula-tion of GFP-tagged Cryptococcus neoformans strains H99, serial cryosections (10 ?m) from 3 C57 BL/6 J mice brains were imaged with immunofluorescence microscopy. GFP-tagged H99 were found in some brain regions such as primary motor cortex-secondary motor cortex, caudate putamen, stratum lucidum of hippocampus, field CA1 of hippocampus, dorsal lateral geniculate nucleus, lateral posterior thalamic nucleus, laterorostral part, lateral posterior thalamic nucleus, mediorostral part, retrosplenial agranular cortex, lateral area of secondary visual cortex, and lacunosum molecular layer of the hippocampus. The results will be very useful for further exploring the mechanism of C. neoformans infection of brain. 

scholarly journals Neurochondrin neurological autoimmunity

2019 ◽  
Vol 6 (6) ◽  
pp. e612 ◽  
Author(s):  
Shahar Shelly ◽  
Thomas J. Kryzer ◽  
Lars Komorowski ◽  
Ramona Miske ◽  
Mark D. Anderson ◽  
...  
Keyword(s):  
Vocal Cord Paralysis ◽  
Molecular Layer ◽  
Cerebellar Atrophy ◽  
Immunofluorescence Assay ◽  
Onset Age ◽  
Neurologic Outcomes ◽  
Progressive Cerebellar Ataxia ◽  
Stratum Lucidum ◽  
Protein Assays

ObjectivesTo describe the neurologic spectrum and treatment outcomes for neurochondrin-IgG positive cases identified serologically in the Mayo Clinic Neuroimmunology Laboratory.MethodsArchived serum and CSF specimens previously scored positive for IgGs that stained mouse hippocampal tissue in a nonuniform synaptic pattern by immunofluorescence assay (89 among 616,025 screened, 1993–2019) were reevaluated. Antibody characterization experiments revealed specificity for neurochondrin, confirmed by recombinant protein assays.ResultsIgG in serum (9) or CSF (4) from 8 patients yielded identical neuron-restricted CNS patterns, most pronounced in hippocampus (stratum lucidum in particular), cerebellum (Purkinje cells and molecular layer), and amygdala. All were neurochondrin-IgG positive. Five were women; median symptom onset age was 43 years (range, 30–69). Of 7 with clinical data, 6 presented with rapidly progressive cerebellar ataxia, brainstem signs, or both; 1 had isolated unexplained psychosis 1 year prior. Five of 6 had cerebellar signs, 4 with additional brainstem symptoms or signs (eye movement abnormalities, 3; dysphagia, 2; nausea and vomiting, 1). One patient with brainstem signs (vocal cord paralysis and VII nerve palsy) had accompanying myelopathy (longitudinally extensive abnormality on MRI; aquaporin-4-IgG and myelin oligodendrocyte glycoprotein-IgG negative). The 7th patient had small fiber neuropathy only. Just 1 of 7 had contemporaneous cancer (uterine). Six patients with ataxia or brainstem signs received immunotherapy, but just 1 remained ambulatory. At last follow-up, 5 had MRI evidence of severe cerebellar atrophy.ConclusionIn our series, neurochondrin autoimmunity was usually accompanied by a nonparaneoplastic rapidly progressive rhombencephalitis with poor neurologic outcomes. Other phenotypes and occasional paraneoplastic causes may occur.

Reinnervation of stratum lucidum by hippocampal mossy fibers is developmentally regulated

1996 ◽  
Vol 95 (2) ◽  
pp. 184-193 ◽  
Author(s):  
Loan B. Nguyen ◽  
Thomas N. Ricciardi ◽  
Alfred T. malouf
Keyword(s):  
Mossy Fibers ◽  
Developmentally Regulated ◽  
Stratum Lucidum

The skin and hair of the southern elephant seal, (Mirounga Leonina (L.) II. pre-natal and early post-natal development and moulting

1967 ◽  
Vol 15 (2) ◽  
pp. 349 ◽  
Author(s):  
JK Ling ◽  
CDB Thomas
Keyword(s):  
Cellular Proliferation ◽  
Elephant Seal ◽  
Hair Follicles ◽  
Southern Elephant Seal ◽  
Mirounga Leonina ◽  
Adult Type ◽  
Root Sheath ◽  
Stratum Lucidum ◽  
Near Term ◽  
Post Implantation

The embryological development of hair follicles and the emergence and growth of the foetal pelage of the southern elephant seal, Mirounga leonina (L.), are described in terms of 10 recognizable stages. Follicle primordia appear at a post-implantation age of about 8 weeks and growth of the first definitive hairs takes approximately 14 weeks. Sebaceous glands develop after the sweat gland anlagen, but their ontogeny is more rapid and they function earlier in the formation of the hair canals. The latter are formed by epidermal cellular accretion from without and sebaceous cellular activity within the developing pilosebaceous unit. Development of three epidermal layers is also described and the absence of a stratum granulosum and stratum lucidum noted. The formation of muscle, collagen, and elastic fibres, and blood vessels in the dermis has been observed and described. The histological development of the first adult-type hair generation has been followed in near-term foetuses and young pups until the latter go to sea. The post-natal moult usually commences about 1 week after birth and takes 3 weeks for its completion. Whereas the foetal hairs are not connected to the stratum corneum lining the pilary canal, with a result that they are shed individually, the epidermis and all subsequent hair generations are united. This union is established after the post-natal moult at the end of the active follicular phase by a process of epidermal and external root sheath cellular proliferation around the bottom of the hair canal.

scholarly journals Age-Induced Loss of Mossy Fibre Synapses on CA3 Thorns in the CA3 Stratum Lucidum

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Bunmi Ojo ◽  
Heather Davies ◽  
Payam Rezaie ◽  
Paul Gabbott ◽  
Francis Colyer ◽  
...  
Keyword(s):  
Wistar Rats ◽  
Synaptic Connection ◽  
Mossy Fibre ◽  
Synaptic Density ◽  
Cellular Processes ◽  
Unbiased Stereology ◽  
Microvascular Changes ◽  
Age Related ◽  
Stratum Lucidum ◽  
Serial Electron Microscopy

Advanced ageing is associated with hippocampal deterioration and mild cognitive decline. The hippocampal subregion CA3 stratum lucidum (CA3-SL) receives neuronal inputs from the giant mossy fibre boutons of the dentate gyrus, but relatively little is known about the integrity of this synaptic connection with ageing. Using serial electron microscopy and unbiased stereology, we examined age-related changes in mossy fibre synapses on CA3 thorny excrescences within the CA3-SL of young adults (4-month-old), middle-aged (12-month-old), and old-aged (28-month-old) Wistar rats. Our data show that while there is an increase in CA3 volume with ageing, there is a significant (40–45%) reduction in synaptic density within the CA3-SL of 12- and 28-month-old animals compared with 4-month-old animals. We also present preliminary data showing that the CA3 neuropil in advanced ageing was conspicuously full of lipofuscin and phagolysosome positive, activated microglial cellular processes, and altered perivascular pathology. These data suggest that synaptic density in the CA3-SL is significantly impaired in ageing, accompanied by underlying prominent ultrastructural glial and microvascular changes.

scholarly journals The distribution of serotonergic nerve on the hippocampus of the fruit bats (Rousettus amplexicaudatus)

2019 ◽  
Vol 12 (9) ◽  
pp. 1460-1466 ◽  
Author(s):  
Vivin Wirawati ◽  
Nourrisma D. A. Widiati ◽  
Geraldus Gunawan ◽  
Golda R. Saragih ◽  
Puspa Hening ◽  
...  
Keyword(s):  
Learning And Memory ◽  
Molecular Layer ◽  
Stratum Radiatum ◽  
Fruit Bats ◽  
Cornu Ammonis ◽  
Stratum Lucidum ◽  
Paraffin Block ◽  
Hippocampus Proper ◽  
La Jolla ◽  
The Brain

Background: Rousettus amplexicaudatus is one of the old world fruit bats, commonly known in Javanese word as codot belongs to Order Chiroptera and suborder Megachiroptera. R. amplexicaudatus possessed an outstanding visual ability, which helps in the process of searching for food. Those activities process and save within the brain involving the learning and memory activities. Learning and memory activities are centered around the hippocampus with the help of serotonergic nerve. Aim: This study conducted to identify the morphology and distribution of serotonergic nerve (5-hydroxytryptamine) in the hippocampus of R. amplexicaudatus, which related to the function of serotonin within the learning and memory process. Materials and Methods: Five R. amplexicaudatus bats were brought from Gunung Kidul cave, Yogyakarta, Java Island, Indonesia. The bats were anesthetized using ketamine and xylazine. R. amplexicaudatus then perfused intracardially. The brain samples were collected processed into paraffin block, and a further cut in 8 μm thickness serially. The tissue slides were stained using hematoxylin-eosin, cresyl echt violet, and immunohistochemistry with rabbit's anti-serotonin (1:200). The results observed and analyzed quantitatively and qualitatively using image J (https://imagej.nih.gov/ij/) (Bethesda, Maryland, USA) and GraphPad Prism 7 (La Jolla, CA, USA). Results: The hippocampus of R. amplexicaudatus composed of the dentate gyrus (DG), hippocampus proper (cornu ammonis 3 [CA3], and CA1 as the main area for learning memory), and subiculum. On the DG serotonin immunoreactive cells found within the granular layer (132±35.03 cells/mm2), polymorphic stratum (86.33±11.23 cells/mm2), and molecular layer (93±1 cells/mm2). Meanwhile, on CA3 area, the immunoreactive cells for serotonin found in each stratum. The number of immunoreactive cells on each stratum from highest to the lowest are stratum pyramidal 123.33±15.88 cell/mm2, stratum molecular 63±13.11 cell/mm2, stratum lucidum 62.67±8.08 cell/mm2, stratum radiatum 55.33±510.21 cell/mm2, stratum oriens 48±3.46 cell/mm2, and stratum alveus 28.67±2.52 cell/mm2. In addition, in CA1 also hampers the immunoreactive cells in the pyramidal stratum, molecular, lucidum, oriens, radiatum, and alveus layer, respectively, of each 91±27.40 cell/mm2, 60.33±20.65 cell/mm2, 53.67±4.51 cell/mm2 44.33±10.40 cell/mm2, 41.33±5.51 cell/mm2, and 27±4 cell/mm2. Conclusion: Taking together the distribution of serotonin-immunoreactive cells in the hippocampus of R. amplexicaudatus mostly found on CA3 followed by CA 1 and DG.

scholarly journals LTD at mossy fiber synapses onto stratum lucidum interneurons requires TrkB and retrograde endocannabinoid signaling

2019 ◽  
Vol 121 (2) ◽  
pp. 609-619 ◽  
Author(s):  
Enhui Pan ◽  
Zirun Zhao ◽  
James O. McNamara
Keyword(s):  
High Frequency ◽  
Mossy Fiber ◽  
Mossy Fibers ◽  
High Frequency Stimulation ◽  
Long Term Depression ◽  
Stratum Lucidum ◽  
Frequency Stimulation ◽  
Retrograde Signal ◽  
Stimulation Of

Hippocampal mossy fiber axons simultaneously activate CA3 pyramidal cells and stratum lucidum interneurons (SLINs), the latter providing feedforward inhibition to control CA3 pyramidal cell excitability. Filopodial extensions of giant boutons of mossy fibers provide excitatory synaptic input to the SLIN. These filopodia undergo extraordinary structural plasticity causally linked to execution of memory tasks, leading us to seek the mechanisms by which activity regulates these synapses. High-frequency stimulation of the mossy fibers induces long-term depression (LTD) of their calcium-permeable AMPA receptor synapses with SLINs; previous work localized the site of induction to be postsynaptic and the site of expression to be presynaptic. Yet, the underlying signaling events and the identity of the retrograde signal are incompletely understood. We used whole cell recordings of SLINs in hippocampal slices from wild-type and mutant mice to explore the mechanisms. Genetic and pharmacologic perturbations revealed a requirement for both the receptor tyrosine kinase TrkB and its agonist, brain-derived neurotrophic factor (BDNF), for induction of LTD. Inclusion of inhibitors of Trk receptor kinase and PLC in the patch pipette prevented LTD. Endocannabinoid receptor antagonists and genetic deletion of the CB1 receptor prevented LTD. We propose a model whereby release of BDNF from mossy fiber filopodia activates TrkB and PLCγ1 signaling postsynaptically within SLINs, triggering synthesis and release of an endocannabinoid that serves as a retrograde signal, culminating in reduced glutamate release. Insights into the signaling pathways by which activity modifies function of these synapses will facilitate an understanding of their contribution to the local circuit and behavioral consequences of hippocampal granule cell activity. NEW & NOTEWORTHY We investigated signaling mechanisms underlying plasticity of the hippocampal mossy fiber filopodial synapse with interneurons in stratum lucidum. High-frequency stimulation of the mossy fibers induces long-term depression of this synapse. Our findings are consistent with a model in which brain-derived neurotrophic factor released from filopodia activates TrkB of a stratum lucidum interneuron; the ensuing activation of PLCγ1 induces synthesis of an endocannabinoid, which provides a retrograde signal leading to reduced release of glutamate presynaptically.

scholarly journals Mossy fiber Zn2+ spillover modulates heterosynaptic N-methyl-d-aspartate receptor activity in hippocampal CA3 circuits

2002 ◽  
Vol 158 (2) ◽  
pp. 215-220 ◽  
Author(s):  
Sayaka Ueno ◽  
Masako Tsukamoto ◽  
Tomoya Hirano ◽  
Kazuya Kikuchi ◽  
Maki K. Yamada ◽  
...  
Keyword(s):  
Nmda Receptor ◽  
Mossy Fiber ◽  
Hippocampal Slices ◽  
Physiological Role ◽  
Chelating Agent ◽  
Stratum Radiatum ◽  
High Frequency Stimulation ◽  
Dependent Manner ◽  
Synaptic Terminals ◽  
Stratum Lucidum

Although Zn2+ is contained in large amounts in the synaptic terminals of hippocampal mossy fibers (MFs), its physiological role in synaptic transmission is poorly understood. By using the newly developed high-sensitivity Zn2+ indicator ZnAF-2, the spatiotemporal dynamics of Zn2+ was monitored in rat hippocampal slices. When high-frequency stimulation was delivered to the MFs, the concentration of extracellular Zn2+ was immediately elevated in the stratum lucidum, followed by a mild increase in the stratum radiatum adjacent to the stratum lucidum, but not in the distal area of stratum radiatum. The Zn2+ increase was insensitive to a non–N-methyl-d-aspartate (NMDA) receptor antagonist but was efficiently attenuated by tetrodotoxin or Ca2+-free medium, suggesting that Zn2+ is released by MF synaptic terminals in an activity-dependent manner, and thereafter diffuses extracellularly into the neighboring stratum radiatum. Electrophysiological analyses revealed that NMDA receptor–mediated synaptic responses in CA3 proximal stratum radiatum were inhibited in the immediate aftermath of MF activation and that this inhibition was no longer observed in the presence of a Zn2+-chelating agent. Thus, Zn2+ serves as a spatiotemporal mediator in imprinting the history of MF activity in contiguous hippocampal networks. We predict herein a novel form of metaplasticity, i.e., an experience-dependent non-Hebbian modulation of synaptic plasticity.

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