Firstly, the number of dendritic spines decreases 6, 11. It is well established that neurons can undergo several major structural changes during aging 11, 12. Furthermore, some dynamic properties associated with aging have been reported 10, however, the effect of dendritic pruning caused by aging on neuronal dynamics remains largely unknown. There are a number of age-related structural changes that occur in the brain at various levels: synapses 6, dendrites 7, circuits 8, gray-matter volume 9. Along with these cognitive changes, aging is also a major risk factor for dementia and neurodegenerative disorders 5. Moreover, our findings suggest that increasing dendritic excitability could partially mitigate the dynamical effects of aging.Īging is often accompanied by cognitive deficits such as forgetfulness, distractibility, inflexibility 1, reduction in speed of processing 2, working and episodic memory 3, inhibitory function 4, and long-term memory. Based on the emergent neuronal dynamics, we propose to classify the effects of dendritic deterioration, and put forward a topological measure of “neuronal reserve” that quantifies the resilience of neuronal dynamics to dendritic pruning. Our measures indicate that the resilience of neuronal dynamics is neuron-specific, heterogeneous, and strongly affected by dendritic topology and the position of the soma. Pruned neurons require less energy but their function is often impaired, which can explain the diminished ability to distinguish between similar experiences (pattern separation) in older people. We show that dendritic pruning affects neuronal integrity: firing rate is reduced, causing a reduction in energy consumption, energy efficiency, and dynamic range. Utilizing a detailed computational modeling approach, we simulate the dynamics of digitally reconstructed neurons obtained from. Here we simulate the aging effects on neuronal morphology as dendritic pruning and characterize its dynamical implications. Although age-related brain structural changes have been observed across multiple scales, their functional implications remain largely unknown. It is often accompanied by reduced cognitive functions, gray-matter volume, and dendritic integrity. Aging is a main risk factor for neurodegenerative disorders including Alzheimer's disease.

Define dendrite pruning