Redistribution of synaptic vesicles during long-term potentiation in the hippocampus

Synaptic vesicles were quantified 20 min after the induction of long-term potentiation (LTP) in the Schaffer-commissural system of the hippocampus. With LTP, significant increases were found in vesicles attached to the active zone membrane, and in the percentage of vesicles adjacent to the active zone. In addition, as others have reported, overall vesicle density was decreased and spine area was increased. These results suggest that an increased probability of vesicle release may contribute to brain LTP.