Mutants lack alpha and alpha' lobes of the mushroom bodies. The more intensively flies are trained, the less they remember; they show almost non memory 5 hours after spaced conditioning. Anasthesia resistant consolidated memory seems to be erased during a long term memory-specific training protocols.

Mutants are bang-sensitive, with a recovery period of 52 +/- 10 seconds and a refractory period of 510 +/- 30 seconds.

Mutant flies show a reduced seizure threshold (of 4.5 +/- 0.2 V) compared to wild type in response to high-frequency electrical stimulation.

1-hour, 3-hour, 24-hour (spaced training) and 24-hour (massed training) memory are normal in mutant flies. 3-hour memory is not reduced in mutant flies lacking either α α' or β β' lobes of the mushroom body. Long term memory (24-hour spaced training) is normal in the flies which have β β' lobes, but is completely abolished in flies which lack the α α' lobes (the long term memory defect is not caused by the fused β β' lobe defect which may be seen in these flies). 24-hour (massed training) memory is not reduced in flies lacking the α α' lobes.