Intermediate and long-term memory are different at the neuronal level in Lymnaea stagnalis (L.)

► Behavioural memory at 3 h (ITM) and 24 h (LTM) are identical. ► Neuronal memory at 3 h (ITM) and 24 h (LTM) are significantly different. ► Excitability of specific interneuron decreases following training. ► A memory trace remains in the neuron after behavioural memory disappears.