Abstract Glutamate-induced neurodegeneration in the mammalian central nervous system may be involved in both normal development and pathological neurodegenerative disorders. Cultured embryonic hippocampal pyramidal neurons were used to test the hypothesis that acetylcholine can modify glutamate-induced neurodegeneration. Acetylcholine potentiated the neurodegenerative actions of glutamate and lowered the threshold for glutamate neurotoxicity. The degeneration-potentiating effects of acetylcholine were mediated by muscarinic receptors. These results emphasize the importance of neurotransmitter interactions in the modification of neuroarchitecture.