Waste Clearance Shapes Aging Brain Health
Meaning Waste clearance in the brain refers to the biological processes responsible for removing metabolic by-products, misfolded proteins, damaged cellular components, and toxins that accumulate during normal neuronal activity. Unlike other organs, the brain lacks conventional lymphatic vessels within its parenchyma and instead relies on specialized systems such as the glymphatic pathway , cerebrospinal fluid (CSF) circulation, blood– brain barrier (BBB) transport mechanisms, and cellular degradation pathways like autophagy and proteasomal systems. These interconnected processes collectively maintain neural homeostasis. As the brain ages, efficiency of waste clearance declines, leading to accumulation of neurotoxic substances that contribute to cognitive decline and neurodegenerative diseases. Introduction Aging is accompanied by progressive changes in brain structure and function, including reduced synaptic plasticity, neuronal loss, and altered neurotransmission. A central ...