(A) Trials to a learning criterion of eight CRs in nine
consecutive trials for four groups of older rabbits treated with 3.0
mg/kg Gal over 15 wk, 3.0 mg/kg Gal over 3 wk, 1.0 mg/kg Gal over
15 wk, or sterile saline vehicle. There was no difference during 15
days of acquisition in rabbits treated with 3.0 mg/kg Gal, so the
groups are collapsed in B. (B) Response
latency over 15 daily acquisition sessions in the older rabbits shown
above treated with 3.0 mg/kg Gal, 1.0 mg/kg Gal, or 0.0 mg/kg
Gal.