The expression of Mmus\PrnpWT.3F4.UAS under the control of Scer\GAL4elav-C155 leads to adults showing a progressive decrease in climbing ability; this phenotype is enhanced by inoculation with brain extracts from individuals expressing Mmus\PrnpFFI.3F4.UAS or Mmus\PrnpCJD.3F4.UAS, but not Mmus\PrnpWT.3F4.UAS (self-inoculation), under the control of Scer\GAL4elav-C155.