@article{articlef0c8acdc,
title   = {Lesion of the ventral periaqueductal gray reduces conditioned fear but does not change freezing induced by stimulation of the dorsal periaqueductal gray},
author = {Vianna, Daniel Machado Luiz and Graeff, Frederico Guilherme and Landeira-Fernandez, Jesus and Brandão, Marcus Lira},
year = {2001},
journal   = {Learning & Memory}
}