Peptides capable of interfering with the Kv2.1-mediated apoptotic K+ current surge that leads to neuronal cell death are described. The disclosed peptides are derived from the C-terminal region of Kv2.1, which mediates binding to the SNARE protein syntaxin. Disruption of Kv2.1 binding to syntaxin inhibits the apoptotic K+ current surge that leads to neuronal cell death. The present disclosure provides methods of inhibiting binding of Kv2.1 to syntaxin in a cell (in vitro or in vivo), such as for neuroprotection following cerebral ischemia, stroke, or traumatic brain injury, or during the course of a neurodegenerative disease, or any other condition associated with neuronal cell death.