β-Bungarotoxin is a potent inducer of apoptosis in cultured rat neurons by receptor-mediated internalization

The neurotoxic phospholipase A2, β‐bungarotoxin (β‐BuTx), is a component of the snake venom from the Taiwanese banded krait Bungarus multicinctus. β‐BuTx affects presynaptic nerve terminal function of the neuromuscular junction and induces widespread neuronal cell death throughout the mammalian and avian CNS. To analyse the initial events of β‐BuTx‐mediated cell death, the toxin was applied to cultured rat hippocampal neurons where it induced neuronal cell death in a concentration‐dependent manner (EC50≈ 5 × 10−13 m) within 24 h. Fluorescence labelled β‐BuTx was completely incorporated by neurons within