A computational model of naming in Alzheimer's disease: Unitary or multiple impairments?

1994 ◽  
Vol 8 (1) ◽  
pp. 3-13 ◽  
Author(s):  
Lynette J. Tippett ◽  
Martha J. Farah
2020 ◽  
Author(s):  
Huayi Gao ◽  
Langzhou Liu ◽  
Shangbin Chen

AbstractDisruptions of astrocyte Ca2+ signaling is important in Alzheimer’s disease (AD) with the unclear mechanism of amyloid beta peptide (Aβ). We have modified our previous computational model of spontaneous Ca2+ oscillations in astrocytes to investigate the effects of Aβ on intracellular Ca2+ dynamics. The simulation results have shown consistence with the previous experiments. Aβ can increase the resting concentration of intracellular Ca2+ and change the regime of Ca2+ oscillations by activating L-type voltage-gated calcium channels and the metabolic glutamate receptors, or by increasing ryanodine receptors sensitivity and Ca2+ leakage, respectively. This work have provided a toolkit to study the influence of Aβ on intracellular Ca2+ dynamics in AD. It is helpful for understanding the toxic role of Aβ during the progression of AD.Statement of SignificanceAlzheimer’s disease (AD) is the most common neurodegenerative disease with the unclear mechanism of amyloid beta peptide (Aβ). This work have implemented a computational model to address the Ca2+ dynamics of astrocyte mediated by Aβ with the four different pathways: voltage-gated calcium channels, metabotropic glutamate receptors 5, ryanodine receptor channels and membrane leak. The Ca2+ oscillations and bifurcation diagram indicate that astrocytes exhibit ionic excitability mediated by Aβ and become the potential targets of Aβ neurotoxicity. We expect this shared computational model would advance the understanding of AD.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Fan Zhu ◽  
Bharat Panwar ◽  
Hiroko H. Dodge ◽  
Hongdong Li ◽  
Benjamin M. Hampstead ◽  
...  

2020 ◽  
Vol 2020 ◽  
pp. 1-26
Author(s):  
Mariana Antonia Aguiar-Furucho ◽  
Francisco Javier Ropero Peláez

Several research studies point to the fact that sensory and cognitive reductions like cataracts, deafness, macular degeneration, or even lack of activity after job retirement, precede the onset of Alzheimer’s disease. To simulate Alzheimer’s disease earlier stages, which manifest in sensory cortices, we used a computational model of the koniocortex that is the first cortical stage processing sensory information. The architecture and physiology of the modeled koniocortex resemble those of its cerebral counterpart being capable of continuous learning. This model allows one to analyze the initial phases of Alzheimer’s disease by “aging” the artificial koniocortex through synaptic pruning, by the modification of acetylcholine and GABA-A signaling, and by reducing sensory stimuli, among other processes. The computational model shows that during aging, a GABA-A deficit followed by a reduction in sensory stimuli leads to a dysregulation of neural excitability, which in the biological brain is associated with hypermetabolism, one of the earliest symptoms of Alzheimer’s disease.


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