Long-term memory assessment after injection with arachidonic acid. A. Protocol indicating timing of injection and start of pre- and post-training tests with respect to the start of the first training session for both the conditioned (CS-UCS) and control (CS-DS) animals. B-D. LTM assessment in animals injected 1 hr before training. There was a robust response to conditioning in both vehicle and arachidonic acid injected animals. Thus all conditioned animals responded with significant feeding movements in the post-training test upon application of the conditioning stimulus. These results indicate that injection with exogenous arachidonic acid does not induce LTM impairment in snails.