Activity-dependent astrocytic cholesterol release fine-tunes modes of synaptic exo- and endocytosis.

Astrocytic cholesterol release dynamically regulates synaptic vesicle exo- and endocytosis modes, affecting presynaptic release and retrieval processes.

• Why it matters: Understanding how cholesterol influences synaptic function is crucial because it impacts neurotransmitter release and synaptic plasticity, yet the specific roles of astrocyte-derived cholesterol remain unclear.
• What they did: Using nanoscale imaging and a cholesterol biosensor, the study examined hippocampal synapses, revealing that astrocytic cholesterol modulates the balance between univesicular and multivesicular release, as well as fast and ultrafast endocytosis, in an activity-dependent manner.
• The result: These findings demonstrate that astrocytic cholesterol release fine-tunes synaptic transmission by adjusting vesicle release modes and spatial distribution, enabling activity-dependent regulation of synaptic strength.