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Figure 2.
Behavioral responses at different
training-testing intervals. A, The percentage of time
animals were freezing (immobile except for respiratory movements) when
placed in the training chamber. Values are for naive control animals
and animals with 0 (24 hr), 1, 2, and 4 week training-testing
intervals (4 animals in each group). Error bars show the SEM.
Asterisks denote behavioral response levels that
differed significantly from that of naive controls
(p < 0.01). B, NGF levels in
hippocampal homogenates collected from both sides of the brains of the
naive control animals and the animals killed at 0 (24 hr), 1, 2, and 4 week intervals after training. Error bars show the SEM. At 1 week after
training (see asterisk), NGF levels were significantly
higher (p < 0.05) compared with that of
naive control animals that were tested but not trained.
