amn^28A flies are less responsive to noxious heat than wild-type flies in a light-driven heat-avoidance assay. When the temperature of the heat band is below 40[o]C, amn^28A mutants show performance index values indistinguishable from (at 30[o]C and 35[o]C) or even lower than (at 25[o]C), those of wild-type flies. At 40-50[o]C, however, a larger proportion of amn^28A flies than wild-type flies cross the heat band. Performance Index values for amn^28A and wild-type flies differ significantly in this temperature range.

amn^28A mutant larvae show a significant delay in response to noxious heat compared to control flies. These flies also exhibit a delay in their jump response to noxious heat of 23 seconds.

amn^28A/amn^X8 females, both larvae and adults, display a prolonged latency in their responses to a noxious heat stimulus.

The formation and retention of aversive memory after associative linalool/quinine hemisulfate conditioning is normal in amn^28A larvae.

Mutant males learn courtship suppression normally if tested immediately after training with a mature decapitated virgin and do not avoid mature virgins after training with an immature female. Introducing a delay between training and with a mature virgin and testing uncovers a more rapid decay of memory in these mutants.

amn^28A mutant larvae exhibit significant Response Index increment due to associative LIN/SUC training, although this increment is significantly lower than in wild-type. They do not exhibit a significant Response Index increase upon exposure to LIN or SUC alone.

The naive olfactory response of amn^28A larvae is slightly higher than in wild-type but not statistically significant. Gustatory response for SUC is also normal.

Memory in amn^28A larvae is considerably short-lived and lost by 30 minutes.

Muscles of third instar amn^28A larvae show a reduction in the L-type Ca²⁺ current compared to control larvae.

Unlike wild-type males, amn^28A homozygous males that have undergone courtship conditioning (kept in the presence of a female for 7 hours) do not spend significantly less time engaged in courtship behaviour when placed with a female 5 days after conditioning than non-conditioned males of the same genotype. Unlike wild-type males amn^28A homozygous males conditioned to the presence of a female for 30 minutes do not spend significantly less time engaged in courtship behaviour when returned to the presence of a female 1 hour later than non-conditioned males.

Mutants exhibit defects in memory retention. In olfactory memory retention tests, a significant reduction is seen in one hour memory, but not much in 0 hours and 7 hour memory. Maximal anaesthesia resistant memory (ARM) levels in mutant animals are the same as controls, but ARM levels at 20 min 30 min and 1 hour after training is significantly lower in mutants than 1 day old wild-type flies. Mutant animals, unlike wild-type, do not show significant age-related memory impairment, 1 hour memory in aged flies was not significantly different from young mutant flies.

In amn^28A homozygotes the amplitude of the synchronous oscillation of intracellular calcium concentration seen in wild type Kenyon cells is significantly increased.

Shows defects in memory retention both immediately (initial learning) or 180 minutes (3 hour memory) after training. Semidominance is restricted to the initial learning phenotype.

Hemizygous males and homozygous females show increased sensitivity to ethanol in an inebriometer assay.