The role of small-conductance calcium-activated potassium (SK) channels in memory formation was explored in chicks trained on a single-trial discrimination avoidance task. Blockade of SK channels using apamin (1 nM, 0.02 ng/hem, i.c.) impaired long-term memory retention when administered between 10 min prior to, and 30 min after, training. Apamin (1 nM, 0.02 ng/hem, immediately post-training, i.c.) resulted in persistent impairment of retention during the long-term memory stage by 90 min post-training until at least 24 h post-training, indicating SK channels contribute to long-term memory.