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OADES AND ISAACSON
12 3 4 5 6 7
Trial
The mean postoperative response latencies of all groups in the passive
avoidance task. Inset shows mean duration of shocks received by each group. Hippocampal
lesions treated with PCPA (Hp), closed triangles, shaded bars; hippocampal lesions treated
with saline (He), open triangles, open bars; neocortical lesions treated with PCPA (Np),
closed squares, shaded bars; neocortical lesions treated with saline (Ne), open squares,
open bars; intact controls treated with PCPA (Cp), closed circles, shaded bars; intact
controls treated with saline (Ce), open circles, open bars.
Since the shock was delivered for as long as animals remained in the
compartment with the water, it is possible to compare the total amounts
of shock each group received over the six trials. The groups with hip-
pocampal damage received more shocks than those with neocortical
damage (P < 0.05) and intact groups (P < 0.002). Over the six shock trials
of Day 1, PCPA-treated intact animals received less shock than those
treated with saline (P < 0.036). The animals with neocortical lesions were
not affected by the PCPA treatment. The PCPA treatment increased the
amount of shock the animals with hippocampal lesions recieved when
evaluated against the performance of intact animals by the Moses test of
extreme reactions (Siegel, 1956). These results support the latency data in
showing that animals with hippocampal damage are impaired in withhold-
ing approach responses in a passive avoidance task.
The treatment of animals with PCPA failed to protect animals with
bilateral hippocampal damage from developing the alterations in behavior