rut^unspecified mutant cultured neurons display a suppression of neuronal response amplitude and a change in response kinetics to high K+ depolarisation with 30 seconds of high K⁺ stimulation. With 60 seconds of high K⁺ stimulation, the response approaches that of wild-type levels. rut^unspecified suppresses the wild-type high K⁺ response in the soma of cultured neurons. The growth cones of rut^unspecified cultured embryonic neurons often have a longer response latency than the soma, along with a stronger amplitude suppression in the growth cone. The rise-time of the growth cone high K⁺ response is decreased strongly by rut^unspecified (to a greater extent than in dnc^unspecified mutants) but that of the soma is increased (to the same extent as dnc^unspecified). rut^unspecified does not alter the basal Ca²⁺ levels in either the soma or the growth cone of cultured embryonic neurons. Release of Ca²⁺ from intracellular stores or the complex electrical activity cause by ion channel interactions can lead to multiple peaks during the high K⁺ response. The prevalence of a shoulder or second peak during the high K⁺ response is suppressed in rut^unspecified mutants.

In homozygotes no effect is seen on the amplitude of the synchronous oscillation of intracellular calcium concentration seen in wild type Kenyon cells.

While the learning index in wild-type flies persists for at least eight hours at the level reached immediately after completion of training, the learning index in rut^unspecified mutants is significantly lower than it is in the wild-type by one hour after training. By three hours after training, the learning index in rut^unspecified mutants is not different from zero.

The population of neurons in the central nervous system that exhibit K⁺ currents differs from wild type; the number of type II neurons is less than half those of wild type, while type IV neurons increase from 42.8% in wild type to 60.2% in rut^unspecified. A larger proportion of K⁺ currents are sensitive to cAMP compared to wild type.

Homozygous flies show no associative learning, heterozygous flies show a slight reduction in associative learning.