neurodegenerative ageing - a human brain depicted as the sand in an hourglass

neurodegenerative ageing neuro degenerative brain dementia alzheimer parkinson disease neurological old man hands dysfunction irreversible deterioration hourglass pathogenesis mitochondrial postmitotic genomic instability telomere attrition epigenetic alterations loss proteostasis cellular senescence deregulated stem cell exhaustion altered intercellular communication mitophagy huntington frontotemporal lobar disruption chronic decrease neuroprotective neurorestorative vulnerable synaptic sclerosis nervous system sand