Mutant animals with a pain^GAL4/pain^NP7022 genotype show pronounced thermal nociception and mechanical nociception defective phenotype. In mechanical niciception test, pain^GAL4/pain^NP7022 trans-heterozygotes respond approximately 40% of the time to a 50mN Von-Frey fiber (compared to 70% in wild-type).

pain^GAL4 homozygous and heterozygous adults are defective in courtship long term memory (reduction in courtship activity 5 days after 7-hours conditioning) while homozygotes exhibit normal courtship short term memory (reduction in courtship activity 30 minutes after 1-hour conditioning) when compared to controls.

pain^GAL4 flies display weakened avoidance of the odorant 4-methyl-cyclohexanol, compared to wild-type controls, which display a strong avoidance for 4-methyl-cyclohexanol perfused air. When exposed to 4-methyl-cyclohexanol at lower concentrations, pain^GAL4 flies display the wild-type preference behavior, suggesting an alteration in response towards this odor.

Male pain^GAL4 flies display a male-male courtship behavior in the morning (Zeitgeber Time: ZT0.5-ZT3). The chaining index (i.e. the percentage of time these males spend courting one another and forming chains) is 10% for these flies, significantly higher than in wild-type males (0%). After recovery from a mild anaesthesia (brief treatments with CO[[2]], nitrogen, or -20[o]C chilling), the intensity of this male-male courtship behavior is greatly enhanced over a long period (up to ~3 hours after CO[[2]] treatment).

pain^EP2451/pain^GAL4 trans-heterozygous flies exhibit strong male-male courtship behavior. In contrast, pain^EP2451/+ heterozygotes do not exhibit obvious male-male courtship behavior.

pain^GAL4/pain^EP2462 trans-heterozygous flies exhibit strong male-male courtship behavior.

pain^GAL4/pain^EP2251 trans-heterozygous flies exhibit strong male-male courtship behavior.

When placed with two decapitated wild-type flies of opposing genders, pain^GAL4 males and wild-type males display a similar delay in courtship initiation, suggesting that pain^GAL4 males are capable of sensing the targets and of initiating courtship behavior. pain^GAL4 mutant males are able to distinguish female from male flies, although the preference index is slight lower as compared with that of wild-type flies. The total time spent by pain^GAL4 males on courting is significantly longer than that observed for wild-type males.

Under dim red light (to remove the effect of visual cues), both wild-type and pain^GAL4 males show a shorter courtship delay than under normal conditions. pain^GAL4 mutant males show a smilar sex-discriminating ability as under white light, whereas wild-type flies spend more time courting the male target, indicating that pain^GAL4 males may have visual deficiencies compared to wild-type flies.

The mating success rate, defined as the percentage of pairs that copulate, is significantly higher in pain^GAL4 homozygous females than wild-type. The time to copulation of pain^GAL4 mutant females is significantly shorter than that of controls. No significant difference is detected in the courtship latency or courtship index (defined as the percentage of time spent courting in a given observation period). These results show that pain^GAL4 mutant females do not elicit increased courtship behavior than control females, and that the rapid copulation of virgin pain^GAL4 mutant females is because of their enhanced receptivity.

No significant difference is observed in locomotion of pain^GAL4 mutant females compared to controls.

pain^GAL4 mutants display impaired negative geotaxis behaviour.

The Johnston's organ of pain^GAL4 mutant flies show impaired neural activity in response to body rotation.

pain^GAL4 mutants do not show impaired auditory response.

pain^GAL4 flies exhibit a reduced avoidance to isothiocyanate-containing food.

pain^GAL4 mutants exhibit normal avoidance to quinine and NaCl. They also exhibit wild-type levels of attraction to sucrose.

pain^GAL4 mutants exhibit wild-type levels of attraction to capsaicin.