scholarly journals Synaptic Loss in a Mouse Model of Euthyroid Hashimoto’s Thyroiditis: Possible Involvement of the Microglia

2021 ◽  
Author(s):  
Fen Wang ◽  
Yao-Jun Cai ◽  
Xiao Ma ◽  
Nan Wang ◽  
Zhang-Bi Wu ◽  
...  
Keyword(s):  
Learning And Memory ◽  
Morris Water Maze ◽  
Spatial Learning ◽  
Hashimoto’S Thyroiditis ◽  
Water Maze ◽  
Hashimoto's Thyroiditis ◽  
Spatial Learning And Memory ◽  
Synaptic Loss ◽  
Activated Microglia ◽  
Euthyroid State

Abstract Background: Hashimoto’s thyroiditis (HT) is an autoimmune illness that renders individuals vulnerable to neuropsychopathology even in the euthyroid state, the mechanisms involved remain unclear. We hypothesized that activated microglia might disrupt synapses, resulting in cognitive disturbance in the context of euthyroid HT, and designed the present study to test this hypothesis. Methods: Experimental HT model was induced by immunizing NOD mice with thyroglobulin and adjuvant twice. Morris Water Maze was measured to determine mice spatial learning and memory. The synaptic parameters such as the synaptic density, synaptic ultrastructure and synaptic-markers (SYN and PSD95) as well as the interactions of microglia with synapses were also determined. Results: HT mice had poorer performance in Morris Water Maze than controls. Concurrently, HT resulted in a significant reduction in synapse density and ultrastructure damage, along with decreased synaptic puncta visualized by immunostaining with synaptophysin and PSD-95. In parallel, frontal activated microglia in euthyroid HT mice showed increased engulfment of PSD95 and EM revealed that the synaptic structures were visible within the microglia. These functional alterations in microglia corresponded to structural increases in their attachment to neuronal perikarya and a reduction in presynaptic terminals covering the neurons.Conclusion: Our results provide initial evidence that HT can induce synaptic loss in the euthyroid state with deficits might be attributable to activated microglia, which may underlie the deleterious effects of HT on spatial learning and memory.

scholarly journals Hyperthermia-Induced Febrile Seizures Have Moderate and Transient Effects on Spatial Learning in Immature Rats

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Nawel Yagoubi ◽  
Yosra Jomni ◽  
Mohsen Sakly
Keyword(s):  
Learning And Memory ◽  
Morris Water Maze ◽  
Spatial Learning ◽  
Water Maze ◽  
Febrile Seizures ◽  
Hot Water ◽  
Spatial Learning And Memory ◽  
Transient Effects ◽  
Hyperthermia Treatment ◽  
Immature Rats

The aim of this study was to characterize a novel animal model hyperthermia-induced febrile seizure and to investigate the impacts of repetitive febrile seizures on spatial learning and memory performances in immature rats.Methods. Rats were subjected to hyperthermia exposure one, two, or three times in 10-day intervals during 30 min in a water bath warmed at 45–50°C and their behaviour was monitored. Morris water maze spatial learning and memory were examined for control and treated groups. Results showed that rats subjected to 30-minute hyperthermia hot water developed rapidly myoclonic jerks and then generalized seizures. After a single hyperthermia exposure, the time for generalised tonic-clonic seizures appearance was 16.08 ± 0.60 min and it decreased gradually with repetitive exposure to reach 12.46 ± 0.39 min by the third exposure. Febrile seizures altered the spatial learning and memory abilities in Morris water maze and increased the time spent to attain the platform after one or two exposures, while after a third exposure rats exhibited the same latency compared to controls. Similar results were obtained in probe test where rats, subjected to hyperthermia for one or two episodes, spent less time in the target quadrant compared to corresponding controls. Further, when platform was moved from northwest to southwest quadrant, memory transfer test indicated that after one or two hyperthermia exposures cognitive performances were slightly altered, while after a third exposure the latency to escape increased significantly compared to untreated group. It was concluded that 30 min of hyperthermia hot water was sufficient to induce febrile seizures in immature rats and an increase of susceptibility was observed with repetitive hyperthermia exposure. Hyperthermia treatment impaired cognitive performances but the effects were mostly transient and moderate.

Intracranial self-stimulation facilitates a spatial learning and memory task in the Morris water maze

Neuroscience ◽  
2008 ◽  
Vol 154 (2) ◽  
pp. 424-430 ◽  
Author(s):  
J. Ruiz-Medina ◽  
I. Morgado-Bernal ◽  
D. Redolar-Ripoll ◽  
L. Aldavert-Vera ◽  
P. Segura-Torres
Keyword(s):  
Learning And Memory ◽  
Morris Water Maze ◽  
Spatial Learning ◽  
Water Maze ◽  
Memory Task ◽  
Spatial Learning And Memory ◽  
Self Stimulation

scholarly journals Using the Morris Water Maze to Assess Spatial Learning and Memory in Weanling Mice

PLoS ONE ◽  
2015 ◽  
Vol 10 (4) ◽  
pp. e0124521 ◽  
Author(s):  
Christopher D. Barnhart ◽  
Dongren Yang ◽  
Pamela J. Lein
Keyword(s):  
Learning And Memory ◽  
Morris Water Maze ◽  
Spatial Learning ◽  
Water Maze ◽  
Spatial Learning And Memory

scholarly journals Microalgae Aurantiochytrium Sp. Increases Neurogenesis and Improves Spatial Learning and Memory in Senescence-Accelerated Mouse-Prone 8 Mice

2021 ◽  
Vol 8 ◽  
Author(s):  
Kazunori Sasaki ◽  
Noelia Geribaldi-Doldán ◽  
Qingqing Wu ◽  
Julie Davies ◽  
Francis G. Szele ◽  
...  
Keyword(s):  
Stem Cells ◽  
Learning And Memory ◽  
Morris Water Maze ◽  
Spatial Learning ◽  
Water Maze ◽  
Amyloid Β ◽  
Spatial Learning And Memory ◽  
And Function ◽  
Samp8 Mice ◽  
Senescence Accelerated Mouse

Much attention has recently been focused on nutraceuticals, with minimal adverse effects, developed for preventing or treating neurological diseases such as Alzheimer's disease (AD). The present study was conducted to investigate the potential effect on neural development and function of the microalgae Aurantiochytrium sp. as a nutraceutical. To test neuroprotection by the ethanol extract of Aurantiochytrium (EEA) and a derivative, the n-Hexane layer of EEA (HEEA), amyloid-β-stimulated SH-SY5Y cells, was used as an in vitro AD model. We then assessed the potential enhancement of neurogenesis by EEA and HEEA using murine ex vivo neurospheres. We also administered EEA or HEEA to senescence-accelerated mouse-prone 8 (SAMP8) mice, a non-transgenic strain with accelerated aging and AD-like memory loss for evaluation of spatial learning and memory using the Morris water maze test. Finally, we performed immunohistochemical analysis for assessment of neurogenesis in mice administered EEA. Pretreatment of SH-SY5Y cells with EEA or the squalene-rich fraction of EEA, HEEA, ameliorated amyloid-β-induced cytotoxicity. Interestingly, only EEA-treated cells showed a significant increase in cell metabolism and intracellular adenosine triphosphate production. Moreover, EEA treatment significantly increased the number of neurospheres, whereas HEEA treatment significantly increased the number of β-III-tubulin+ young neurons and GFAP+ astrocytes. SAMP8 mice were given 50 mg/kg EEA or HEEA orally for 30 days. EEA and HEEA decreased escape latency in the Morris water maze in SAMP8 mice, indicating improved memory. To detect stem cells and newborn neurons, we administered BrdU for 9 days and measured BrdU+ cells in the dentate gyrus, a neurogenic stem cell niche of the hippocampus. In SAMP8 mice, EEA rapidly and significantly increased the number of BrdU+GFAP+ stem cells and their progeny, BrdU+NeuN+ mature neurons. In conclusion, our data in aggregate indicate that EEA and its constituents could be developed into a nutraceutical for promoting brain health and function against several age-related diseases, particularly AD.

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