Fig. 6.

l-NAME treatment before training blocks long-term memory. The experiment was identical to that in Figure4, except that the test of memory was performed after 24 hr. For animals treated with l-NAME, n = 7; for animals treated with seawater, n = 4; for naive animals, n = 6. A, There was a significant decrease in the time to stop responding to the inedible food between the training and testing session for the control animals (p < 0.001;t₍₃₎ = 25.37) but not for thel-NAME-treated animals (p = 0.32; t₍₆₎ = 1.08; 2-tailed pairedt tests). In addition, there was a significant difference in the percentage of change in response between the training and testing session between animals treated with l-NAME and seawater (p < 0.001;t₍₉₎ = 10.13; 2-tailed ttest). B, There was a significant decrease in the time that food was in the mouth during the first 5 min from the training and testing session for the control animals (p = 0.005; t₍₃₎ = 7.19) but not for thel-NAME-treated animals (p = 0.33; t₍₆₎ = 1.06; 2-tailed pairedt tests). In addition, there was a significant difference between l-NAME- and seawater-treated animals in the percentage of change in response from the training to the testing session (p = 0.002;t₍₉₎ = 4.14; 2-tailed ttest).