Quinacrine acts like an acetylcholine receptor antagonist rather than like a phospholipase A2 inhibitor in a passive avoidance task in the chick.

Quinacrine (QU) is an inhibitor of phospholipase A2 (PLA2). However, QU has antagonistic properties at the acetylcholine receptor as well. To investigate if PLA2 activity is of importance in memory formation, QU was tested in a passive avoidance task in the chick. Injecting QU pretraining caused amnestic effects 45 min post-training. When comparing this result with results obtained with other PLA2 inhibitors, it became apparent that QU is not acting primarily as an inhibitor of PLA2. Scopolamine, an acetylcholine receptor antagonist, was tested and produced the same onset of amnesia as QU. I conclude that QU is acting functionally as an antagonist of acetylcholine receptors rather than of PLA2.