Fig. 4.

Impairment of sensitization of the shortening reflex by S-cell axon lesions. Shown is the mean percentage of initial contraction for leeches in the experimental (lesion), sham (control), and habituation–control groups across habituation training 6–8 d after cutting the S-cell axon. Leeches in the experimental and control groups experienced a sensitizing stimulus before the onset of repeated presentations of the weak, habituating stimulus, whereas leeches in the habituation–control group did not experience a sensitizing stimulus. Error bars indicate SEM.