Expressing Ocun\PRNP^UAS.cFa under the control of Scer\GAL4^BG380, Scer\GAL4^da.PU does not induce defects adult climbing ability or lifespan, respectively, as compared to controls. Upon expression under the control of Scer\GAL4^ey-OK107, adult mushroom body axonal lobes have normal morphology but Kenyon cell body clusters are smaller fail to expand.

The brains of flies expressing Scer\GAL4^da.G32>Ocun\PRNP^Scer\UAS.cFa for 30 days display only a few vacuoles in the optic lobes and none in the brain neuropil. The cortex of the Scer\GAL4^da.G32>Ocun\PRNP^Scer\UAS.cFa flies contains few micro-vacuoles, suggesting no neuronal degeneration.

Flies older than 40 days expressing Scer\GAL4^ey-OK107>Ocun\PRNP^Scer\UAS.cFa display completely normal morphology of the mushroom body lobes alpha, beta and gamma.

Older flies expressing Ocun\PRNP^Scer\UAS.cFa under the control of Scer\GAL4^ey-OK107 show an insignificant reduction in the size of Kenyon cell clusters compared to controls.

Flies expressing Ocun\PRNP^Scer\UAS.cFa under the control of Scer\GAL4^BG380 perform well in climbing assays up to 20 days of age, but they show a progressive loss of motor-coordination compared with control flies. The Scer\GAL4^BG380>Ocun\PRNP^Scer\UAS.cFa-expressing flies completely loose the ability to climb by day 30.