Function of lipid droplets and lipoproteins in physiology and pathology of the CNS. (A and B) Circular schematic depicting the physiological and pathological functions of lipid droplets and lipoproteins. (C) Tripartite circular schematic showing defense roles of CNS lipoproteins: Neutralization (left section): Astrocyte- and microglia-derived lipoproteins sequester and solubilize Aβ aggregates and other extracellular debris. Detoxification (right section): Neurons under stress release excess fatty acids and toxic lipids, which are captured by lipoproteins and taken up by astrocytes and microglia. These glial cells form lipid droplets to store and detoxify these lipids through distinct metabolic pathways. Lipid recycling (bottom section): Astrocytes and microglia secrete lipoproteins that deliver cholesterol and phospholipids to neurons and oligodendrocytes. This supports membrane remodelling, synapse integrity, and remyelination during recovery. Aβ, amyloid-β.