Contributions of Matrix Metalloproteinases to Neural Plasticity, Habituation, Associative Learning and Drug Addiction
Figure 3
Mean ( SEM) group changes in number of HSR per 3-trial blocks during sessions I and II of habituation trials separated by a 24 hours ISI. (a) These independent groups of rats were bilaterally infused into the dorsal hippocampus with artificial cerebrospinal fluid (aCSF, 2.5 L each side), a low dose of FN-439 of 25 g (Low FN-439), or a high dose of FN-439 of 50 g (High FN-439) at 5 and 60 minutes following the termination of session I. All groups received a contingent signaling tone immediately prior to the air stimulus on each trial. There were no differences among the groups concerning the pattern of habituation during session I. There were differences among the groups during the first trial block of session II with the high FN-439 group revealing a significantly higher level of spontaneous recovery (poorer memory retention) as compared with the other two groups that did not differ. (b) Members of these two groups were bilaterally infused with aCSF or MMP-3 inhibitor (MMP-3i, 50 g in 2.5 L aCSF) into the dorsal hippocampus at 5 and 60 minutes following the conclusion of session I. Members of both groups received contingent tone immediately pior to the application of the air stimulus on each trial. The two groups did not differ regarding pattern of habituation during session I; however, members of the MMP-3 inhibitor group revealed a significantly higher level of spontaneous recovery (poorer memory retention) as compared with the aCSF group during the first trial block of session II, *, modified from Wiediger and Wright [136].
