SV2A (synaptic vesicle glycoprotein 2A) is an integral membrane glycoprotein localized to synaptic vesicles throughout the brain that plays critical roles in synaptic function and disease. Structurally, SV2A contains a large fourth luminal domain and functions as a putative membrane transporter 1. Primary functions include modulating action potential-dependent neurotransmitter release, particularly GABAergic signaling in limbic regions 2, and controlling synaptotagmin-1 trafficking and localization at the presynapse 3. SV2A also serves as a receptor for botulinum neurotoxin type A 1. Clinically, SV2A is the target of major antiepileptic drugs: levetiracetam and its derivative brivaracetam bind to SV2A's substrate-binding site, with brivaracetam showing 15-30 fold higher affinity 41. Loss-of-function SV2A mutations cause developmental and epileptic encephalopathy 113 2. SV2A-knockout mice exhibit severe seizures, and altered SV2A expression occurs in various epileptic disorders 2. Beyond epilepsy, SV2A serves as a biomarker for synaptic density via PET imaging using radiotracers like 11C-UCB-J, enabling assessment of synaptic pathology in neurodegenerative diseases, depression, and PTSD 56. Lower SV2A density correlates with depression severity and network alterations 6, suggesting therapeutic potential in restoring synaptic connections.